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Photodetectors are widely employed in research and innovation, necessitating swift response times, precision, and stability. However, their application in commercial and industrial settings is hindered by limited flexibility and a constrained capacity to respond across a broad spectrum. In this study, we adopted a facile, cost-effective, and room temperature Successive Ionic Layer Adsorption and Reaction (SILAR) technique to craft thin films of Cobalt-doped ZnS on a flexible paper substrate. The Cobalt doping, with varying wt.% (0, 0.5, 1, and 1.5) exhibiting excellent responsivity to both UV and visible spectra. Zinc Sulfide (ZnS), renowned for its wide bandgap, serves as a versatile semiconductor, making it an ideal candidate for photodetectors. The introduction of Cobalt broadened the responsivity of ZnS, covering a wide spectrum, including UV and visible regions. Structural confirmation of the material was achieved through XRD and Raman analyses. Scanning Electron Microscopy revealed the aggregated spherical nanostructure of ZnS on the cellulose substrate. Verification of Cobalt presence in the ZnS thin film and assessment of elemental oxidation states were conducted using XPS. Temporal response and I–V characteristics of the device were evaluated under varying light conditions, specifically at wavelengths of 325 nm and 700 nm at different intensities. Responsivity calculations yielded values of 22.5 mA/W for UV illumination (light intensity 0.6 mW/cm2) and 37.6 mA/W (light intensity 0.4 mW/cm2) for visible light, with corresponding response times recorded as 1.45 s and 2.13 s, respectively. In addition to performance assessments, bending cycle studies were conducted, demonstrating the excellent flexibility of the device up to 800 cycles. The Cobalt-doped ZnS device, as fabricated, emerges as a promising material for energy harvesting. [Display omitted] • Cobalt doped ZnS thinfilms were fabricated using facile Successive ionic layer adsorption and reaction technique on paper substrate. • The inclusion of Cobalt resulted in an expansion of the spectral responsivity of pure ZnS. • Cobalt-doped ZnS device exhibited high responsivity and detectivity across both UV and visible light spectra. • The fabricated device demonstrated resilience, enduring 1000 bending cycles without functional compromise. [ABSTRACT FROM AUTHOR]

Detection of organic pollutants and biomolecules at very low concentrations is a great challenge for protecting the environment and diagnosis of human health. Noble metal nanomaterials have been employed as active surface-enhanced Raman spectroscopy (SERS) substrates for such detection but suffer with high cost. The two-dimensional (2D) transition-metal dichalcogenides (TMDs) can be used as cost-effective alternative SERS substrates for the detection of organic impurities and biomolecules. Here, we report the hydrothermally synthesized in-situ grown MoS 2 films over conducting carbon paper (CCP) and fluorine-doped tin oxide (FTO) coated glass and used them as SERS substrates for the detection of Rhodamine 6G (R6G), vitamin B 12 and bilirubin. We observe that hydrothermally in-situ grown MoS 2 film over FTO coated glass (MoS 2 -FTO) shows a better SERS detection limit for studied analytes compared to the in-situ grown MoS 2 film over conducting carbon paper (MoS 2 -CCP). We observe the detection of R6G, vitamin B 12 , and bilirubin with maximum enhancement factors of 2.42 × 106, 4.18 × 102, and 2.78 × 106, respectively, using MoS 2 -FTO as SERS substrate. Furthermore, we demonstrate the electrochemical-SERS (EC-SERS) activity of prepared SERS substrates. The MoS 2 -FTO shows a better EC-SERS signal as compared to MoS 2 -CCP due to the high conductivity (maximum charge transfer at oxidation potential), strong chemical adsorption, change of orientation, and density of the molecules on the surface of the substrate. [Display omitted] • Hydrothermal synthesis of in-situ grown MoS 2 film over conducting carbon paper and FTO coated glass substrate. • SERS detection of R6G, vitamin B 12 and bilirubin molecules. • Detection of R6G (10−10M), vitamin B 12 (10−6M) and bilirubin (10−10M) using MoS 2 -FTO as SERS substrate. • Enhancement factor of 2.42 × 106 (R6G), 4.18 × 102 (vitamin B 12) and 2.78 × 106 (bilirubin) using MoS 2 -FTO as SERS substrate. • Demonstration of electrochemical-assisted SERS (EC-SERS) biosensor for improved SERS signal. [ABSTRACT FROM AUTHOR]

A derivative of fluorescein was designed, synthesized, and characterized by FT-IR, 1H, 13C NMR, mass spectrometry, and quantum chemical calculations. When applied to the set of solutions containing different cations, it has shown a selective colorimetric and fluorescence response for Cu2+. A visible color change from colorless to purple and from non-fluorescent to red fluorescence was observed. A linear relationship between Cu2+ concentration and absorbance or fluorescence intensity was demonstrated with low detection limits (0.64 and 0.24 μM, respectively) in the acetonitrile/water mixture. Test strips are made by impregnating filter paper with acetonitrile chemosensor 1 solution and used to detect Cu2+ in water. The strips noticeably change their color from colorless to purple. • Chemosensor 1 has been designed and synthesized for selective recognition of Cu2+. • Structure of 1 has been confirmed by 1H, 13C NMR, FT-IR, and mass spectrometry. • Cu2+ ions cause visible color change of the hydrazone solution. • Cu2+ ions turn-on the red fluorescence of the chemosensor. • The limit of detection value is 0.24 μM. [ABSTRACT FROM AUTHOR]

Recent work on the development of integrated thermographic phosphors and digital image correlation (TP+DIC) for combined thermal–mechanical measurements has revealed the need for a flexible, stretchable phosphor coating for metal surfaces. Herein, we coat stainless steel substrates with a polymer-based phosphor ink in a DIC speckle pattern and demonstrate that the ink remains well bonded under substrate deformation. In contrast, a binderless phosphor DIC coating produced via aerosol deposition (AD) partially debonded from the substrate. DIC calculations reveal that the strain on the ink coating matches the strain on the substrate within 4% error at the highest substrate loads (0.05 mm/mm applied substrate strain), while the strain on the AD coating remains near 0 mm/mm as the substrate deforms. Spectrally resolved emission from the phosphor is measured through the transparent binder throughout testing, and the ratio method is used to infer temperature with an uncertainty of 1.7 °C. This phosphor ink coating will allow for accurate, non-contact strain and temperature measurements of a deforming surface. • A simultaneous full-field strain and temperature measurement technique is utilized. • A flexible polymeric phosphor coating is compared to aerosol deposited phosphors. • Aerosol deposited coating cracks under substrate deformation. • Polymer coating deforms with the substrate allowing for accurate strain measurements. [ABSTRACT FROM AUTHOR]

This paper examines how varying the thickness of the indium tin oxide (ITO) seed layer, ranging from 8 to 20 nm, impacts the optical, electrical, and structural properties of triple-layer transparent conductive oxide ITO/aluminum doped zinc oxide (AZO)/ITO. ITO and AZO films were deposited by DC and RF magnetron sputtering, respectively. The thickness and density of each layer were measured by X-ray reflectometry (XRR). X-ray diffraction showed that as the thickness of the ITO seed layer increased, both the average size of the crystallites and the volume of the crystalline phase in the AZO film also increased. Measurements of the electrical characteristics indicated a decrease in resistivity as the thickness of the ITO seed layer increased. This reduction is attributed to enhanced charge mobility, resulting from improved crystallinity. It has been shown that a 20-nm-thick ITO seed layer is sufficient to achieve a charge mobility comparable to that of pure ITO films. The photoluminescence spectra have shown a decrease in the concentration of the oxygen vacancies with the introduction of both the cover and seed layers of ITO. The figure of merits (FOM) of the triple-layer coatings and the optical constants of the AZO and ITO films were calculated. The results of this paper indicate that the ITO20/AZO48/ITO12 triple-layer coating possesses optimal characteristics for use in high-efficiency silicon solar cells. [Display omitted] • ITO seed layer with a thickness >8 nm improves AZO layer crystallinity. • 20 nm ITO seed layer enough to increase mobility from 9.56 to 41.34 cm2V−1s−1. • Introduction of ITO layers decreases concentration of oxygen vacancies in AZO layer. • ITO12/AZO48/ITO20 layer has the best FOM equal to 9.13 10−4 □ Ω−1. • 60–76 % replacement of ITO by AZO improves transparency in the region of 350–1100 nm. [ABSTRACT FROM AUTHOR]

The ferroelectric perovskite material Cs 2 AgBiBr 6 has received much attention because of its low poisonous nature and environmental stability. In this paper, we prepared high-quality Cs 2 AgBiBr 6 thin films for self-powered photodetectors using a low-pressure-assisted method, investigated their optical, electrical, and pyroelectric properties, and characterized the film morphology and crystallization. The device modulates the photoelectric process without an external power supply, and has a maximum switching ratio of 1.72 × 106, a response rate of 0.158 A/W, a specific detectivity of 1.39 × 1011 Jones, an external quantum efficiency of 52.8 %, and a fast response time of 15.4/16.8 μs when irradiated with 532 nm light, which is much better than that of previous self-powered devices with the same material on/off ratio and specific detectivity. It is worth mentioning that the pyroelectric effect was observed in the infrared band. In addition, the devices exhibited high stability to water and oxygen in an air environment (25 °C, 60 % humidity), retaining more than 95 % of the initial performance after one month of placement. Our study demonstrates that the lead-free perovskite Cs 2 AgBiBr 6 is a promising and environmentally friendly alternative for the preparation of highly stable self-powered photodetectors and is also of great research value in the field of pyroelectric detection. • The pyroelectric effect of the Cs 2 AgBiBr 6 thin-film device was observed in the infrared band. This paper explains the effect in terms of light-induced changes in the temperature gradient. • The Cs 2 AgBiBr 6 thin films are prepared by a low-pressure-assisted method and the devices have good morphology and properties. • The device modulates the photoelectric process without an external power supply and has a maximum switching ratio of 1.72 × 106 and a response time of 15.4/16.8 μs. The device retains more than 95 % of the initial performance after one month of placement in an air environment (25 °C, 60 % humidity). [ABSTRACT FROM AUTHOR]

Perovskite light-emitting diodes (PeLEDs) are widely used in optoelectronics due to their excellent performance. The hole transport layer (HTL) plays a crucial role in the performance of the device. In this paper, we prepared quasi-two-dimensional perovskite light-emitting diodes with doping CsBr into PEDOT:PSS as a composite HTL, and investigated the optoelectronic properties of the devices. The maximum luminance of the CsBr-doped device was 6652 cd/m2 and the maximum current efficiency (CE) was 7.55 cd/A, which were increased by 112 % and 80 % compared with the undoped device, respectively. This is primarily due to the PEDOT:PSS/CsBr composite HTL optimizes the morphology of the perovskite film, passivates the defects of the perovskite film, and suppresses the exciton quenching at the HTL/perovskite emission layer (EML) interface. Meanwhile, CsBr doping helps to enhance the hole transport ability of HTL and thus increase the exciton recombination efficiency, which improves the device performance. The results in this paper can provide experimental support for the development of PeLEDs. • Optimized the hole transport layer (HTL) and prepared quasi-two-dimensional perovskite light-emitting diodes by doping CsBr into PEDOT:PSS. • Enhanced PL strength, suppresses exciton bursting at the HTL/emission layer (EML) interface. • Passivation of defects in perovskite films and enhancement of crystallinity. • Enhanced hole injection ability and exciton recombination efficiency in HTL. • Optimized PeLED's performance is improved in every way. [ABSTRACT FROM AUTHOR]

In the third-harmonic-generation crystal of Inertial Confinement Fusion (ICF) system, the transverse stimulated Raman scattering (TSRS) is one of the most destructive nonlinear scattering effects. In this paper, the effects of time-phase modulation on TSRS are studied in KDP and KD*P. The time-phase modulation is analyzed theoretically and "the fastest growth condition of Stokes light" is proposed. And the finite difference method is used to calculate Maxwell-Bloch-Langevin equations describing TSRS. The results show that the time-phase modulation can greatly reduce peak intensity and peak fluence of Stokes light. In addition, the effects of time-phase modulation on TSRS are also analyzed in detail when time-phase modulation model, pump pulse width, pump peak intensity and pump beam aperture are changed. By analysis and calculation, we give reasonable suggestions for the selection of the above working parameters. • In this paper, the effects of time-phase modulation on TSRS are studied in KDP and KD*P. • The time-phase modulation is analyzed theoretically and "the fastest growth condition of Stokes light" is proposed. • And the finite difference method is used to calculate Maxwell-Bloch-Langevin equations describing TSRS. [ABSTRACT FROM AUTHOR]

This paper gives a brief overview on the recent advances on photonic devices based on carbon materials such as: graphene waveguides or photonic devices on paper or plastic substrates in analogy with carbon based electronic devices. The four building block for electronics are the electrons as carrier's information's vectors, the generators, the cables and the transistors. In the same way, photonics or plasmonics will achieve in the future the capability to do same operations done actually in electronics by using photons or plasmons. Following the same steps as in electronics, new technologies were developed in photonics in order to produce photonic integrated circuits (PIC) first on silicon and more recently on plastic or paper substrates. If we analyze the present achievements we can notice that the already equivalent building blocks for photonics on paper substrates are already done: laser on paper substrate (as signal generators), optical and plasmonic waveguides (as information transport cables), optical and plasmonic transistors, photodetectors based on carbon materials etc. In this paper we present by analogy with electronics the recent advancements on paper and carbon based photonics devices. As for electronics, some of the most important advantages of these materials are that they are mechanically flexible, lightweight, cheap and environmentally friendly. • A briefly overview on technologies and materials for photonics on paper substrates. • State of art on perovskite materials for solar cells, LED and lasers. • State of art on plasmonic modulators based on graphene. • New perspectives for the development of future integrated photonic devices. [ABSTRACT FROM AUTHOR]

This paper investigates the potential of zinc aluminate (ZnAl 2 O 4)-based microwave dielectric ceramics for use as materials in the 4–10 GHz band for patch antennas. Microwave dielectric nanoceramics (MDNC) play a vital role in the telecommunications industry, and ZnAl 2 O 4 stands out as a particularly intriguing and promising nonmetal for wireless microstrip antennas. X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) assessments confirm the presence of both ZnAl 2 O 4 and TiO 2 /V 2 O 5 , establishing a dual-phase system. Simultaneously, energy dispersive spectroscopy (EDS) is utilized to scrutinize the composite nanoparticles for functional groups, morphology, and elemental composition. The introduction of titanium dioxide/vanadium pentoxide results in a significant augmentation of both crystallite and grain sizes. The estimated size of the nanoparticles' crystallites is 19 nm, while the dielectric permittivity and dielectric loss range between 22.82 and 22, and 0.14 and 0.007, respectively. This paper presents the key parameters of the fabricated patch antenna, denoted as (1- x)ZnAl 2 O 4 x (0.6 wt%V 2 O 5 -0.4 wt%TiO 2) (ZAVT). The antenna's performance is defined by a return loss (RL) of −44.69 dB, a bandwidth spanning 1.723 GHz, and a voltage standing wave ratio (VSWR) of 1.23, all observed consistently at an operational frequency of 8.73 GHz in both measured and simulated scenarios. • Material & Composition: Antenna fabricated from titanium co-doped ZnAl 2 O 4 V 2 O 5 composite ceramic Nanoparticles, integrating TiO2 for enhanced characteristics. • Operational Specs: Operates at 8.73 GHz with substrate dimensions of 1.6 mm thickness, 2.5 mm length, and 1.5 mm width. • Dielectric Properties: Exhibits stable dielectric permittivity across a frequency range of 100 Hz to 16 MHz. • Loss Characteristics: Decreasing dielectric loss with inceasing frequency, indicating reduced energy dissipation. • Performance Analysis: outperforms similar antennas at 8.73 GHz, with HFSS simulation showing significant gain, directivity and efficiency. [ABSTRACT FROM AUTHOR]

This paper introduces an innovative photonic crystal device that amalgamates a low cross-talk GaAs waveguide intersection with a ring employing phase change material (PCM) for application in all-optical neuromorphic synapses. The device uses a degenerate optical cavity housing Germanium–Antimony-Telluride (GST) phase-change material whose optical properties can be manipulated via a control signal. The proposed design facilitates the development of a non-volatile synapse for photonic neural networks and optical neuromorphic circuits. Numerical simulations using the finite difference time domain method (FDTD) exhibit a notably high-quality factor of 900 and a minimal cross-talk level of −60 dB at the intersection of two waveguides. To validate the FDTD results, the structure undergoes further simulations using the finite element method (FEM), confirming the accuracy of the initial calculations. The resultant structure achieves transmissions of 81 % and 13 % in the amorphous and fully crystalline states of PCM, respectively, enabling low output power in the crystalline state and high output power in the amorphous state. Moreover, modulation of the transmission coefficient between 13 % and 81 % is feasible by manipulating the crystallization coefficient of GST materials. To reduce the effect of the imaginary part of the refractive index of the GST material, the evaluation of the output transmission results for the GSST material (Ge 2 Sb 2 Se 4 Te 1) has been performed. The results revealed that, despite having a lower imaginary part of the refractive index compared to GST, GSST exhibits lower absorption in both amorphous and crystalline states. However, the use of GSST materials shows a 27 % reduction in the figure of merit (FOM), indicating a lower effective range and fewer degrees of freedom in the different crystallization levels of the PCM ring. To investigate the effect of fabrication defects and structural sensitivity, the radius of photonic crystal rods and the rings of GaAs and GST have been changed, and the results indicate that the radius of the photonic crystal rods and the GST ring have negligible effects on the output transmission and resonant wavelength. However, the thickness of the GaAs ring shows a high sensitivity, which leads to a change in the resonance wavelength that is utilized as an effective tool for tuning the pass wavelength through the structure within the 171 nm bandgap range. The transmission loss in the amorphous state is −0.6 dB and in the fully crystalline state −7.5 dB, which is attributed to the absorption of GST material. This proposed photonic crystal synapse structure with an area of less than 30 μm2 significantly minimizes the required space compared to similar silicon photonic structures and increases the prospects for integration and scalability. The compatibility of the materials employed with optical fibre communications at the 1310 nm wavelength further bolsters the practical feasibility of this design. In summary, this paper presents a significant advancement in the domain of neuromorphic photonics by introducing a promising structure with substantial potential for neural network synapses. • A photonic crystal device combining a waveguide intersection with a ring made of phase-change material is presented. • A non-volatile synapse suitable for integration in photonic neural networks is presented. • A notably high-quality factor of 900 and minimal cross-talk of −60 dB at the waveguide intersection is obtained. • Achieves transmittance of 70 % and 20 % in amorphous and fully crystalline states of PCM. • Occupying less than 100 μm2, the proposed synapse minimizes space requirements compared to silicon photonic structures. [ABSTRACT FROM AUTHOR]

Organic light emitting diodes (OLEDs) have gained a remarkable position in display industries, because of its high flexibility and wide color gamut features. A number of OLED structures have been demonstrated in the recent years with an aim to make proficient device. In this paper, an H-shaped single layer OLED design has been proposed. An intensive investigation over various design challenges such as, device potential, current density, luminescent power, electric field, recombination rate and single exciton densities have been analyzed with the help of analytical modeling and a number of mathematical simulations. The complete analyses of H-shaped OLED are performed by utilizing Atlas 2-D TCAD device simulation. The H-shaped structure of the device consists of small distance between anode and cathode in some regions that leads to high potential. Therefore, it directly results in the current density augmentation of the device and hence high performance is achieved. Furthermore, owing to high carrier injection that improves the overall recombination rate significantly and enables high singlet exciton density. Besides this, for fair estimation of H-shaped device performance, investigation at various intentional doping levels is analyzed. Additionally, more depth analysis has been investigated with incorporation of graphene oxide buffer layer. This analysis results in superior luminosity that can be employed for high current and reliable applications. • In this paper, an H-shaped single layer OLED design has been proposed. • Investigation of various design challenges has been performed via analytical modeling and several mathematical simulations. • The complete analysis of H-shaped OLED are performed by utilizing Atlas 2-D TCAD device simulation. • The H-shaped device consists of a small distance between anode and cathode in some regions that leads to high potential. • Therefore, it directly results in the current density augmentation of the device and hence high performance is achieved. • Due to high carrier injection, the recombination rate improves significantly and enables high singlet exciton density. • For fair estimation of H-shaped device performance, investigation at various intentional doping levels is analyzed. • Additionally, more depth analysis has been investigated with incorporation of graphene oxide buffer layer. • This analysis results in superior luminosity that can be employed for high current and reliable applications. [ABSTRACT FROM AUTHOR]

In this paper, we present a detailed study of the effect of WO 3 and Ni films in the presence of BP and BlueP-MDC nanomaterial layers on the sensitivity of a surface plasmon resonance (SPR) following the change in refractive index of the detection medium. Our nanostructure is based on the Kretschmann multilayer configuration composed of a BK7 prism, an Ag metallic film deposited on ZnO and a hybrid multilayer composed of WO 3 /Ni/2D-nanomaterials. In the first part, the study aims to optimize the effect of the thicknesses of the layers of the nanomaterials of the structure on the surface plasmon resonance. We obtain an angular sensitivity of the order of 480 deg/RIU for a figure of merit of 177.11 RIU−1 at the wavelength of 633 nm. These values are respectively 300% and 342% higher than those of a conventional SPR sensor (BK7/Ag/SM). After modeling the SPR biosensor studied in this paper, we showed how the plasmon resonance and sensitivity of the SPR sensor are affected by the refractive index of liquid biochemical elements. The proposed SPR structure can be used in highly sensitive urinary glucose detection and medical analysis applications. [Display omitted] • Engineering and optimization of the SPR device highly sensitive for biomedical processing and detection. • The optimized nanostructure shows the highest sensitivity 480 deg/RIU. • Highest sensitivity enhancement 300% for SPR biosensor. • This study demonstrated high FoM of 177.11 RIU-1 with an enhancement of 342%. • Detection of glucose concentration in human urine samples to test the glucose levels of people with diabetes. [ABSTRACT FROM AUTHOR]

The production of green and clean energy in the current era is heavily reliant on light harvesting through the use of solar cells. A successful fabrication of any of the components of Dye-sensitized solar cells (DSSC) through an easy, environmental, and economic-friendly method would be an added advantage in promoting the production of green and clean energy. With this in mind, this paper highlights the green synthesis of materials for the preparation of photo-anodes as well as sensitizers. Apart from the routine synthesis method, this paper presents a new perspective that enhances inter-particle connections by providing an optimum calcination temperature (thermodynamic sintering) during the preparation procedure. The best calcination temperature for the preparation of photo-anode material is initially optimized by comparing the device output performance between synthetic and natural dyes. Further improvement in device performance is achieved through TiCl4 (Titanium tetrachloride) post-annealing treatment on the optimized photo-anodes. The improvement in performance of these optimized photo-anodes is checked and confirmed with different natural, synthetic, and cocktail sensitizers. The best natural dye-sensitized solar cell (NDSSC) device showed an efficiency of 4.65 % and the dye-sensitized solar cell (DSSC) device showed an efficiency of 5.78 %. This confirms the suitability of these green-synthesized TiO2 nanopowders as a promising material for photo-anode preparation that could work well for both NDSSC and DSSC. [Display omitted] • Green synthesis of TiO 2 nanoparticles with mixed-phase using Hypochaeris radicata as a capping agent. • The importance and superior quality of TiO 2 prepared via green synthesis are highlighted. • The output parameters of the device are enhanced with the post-treatment of the photoanode. • Performance of photoanodes sensitized with different natural and synthetic dyes are highlighted. [ABSTRACT FROM AUTHOR]

A three-layer adjustable THz wave absorber is introduced in this paper. The structure's geometry is heavily based on a combination of periodic graphene disks and their complementary patterns. Also, the middle layer is considered an air gap while the graphene patterns are stacked into TOPAS filler. Additionally, a golden back reflector is placed at the bottom of the absorber to ensure a blocked transmission channel. This configuration is modeled exclusively by passive circuit elements, while full wave simulation is also performed. Also, a simple genetic-based algorithm is exploited to optimize design parameters in numerical values, including geometrical and stimulation values. In addition, a mechanical tuning setup is suggested that can interestingly change absorption peaks. The frequency shift of absorption peaks can be up to 5 THz, which makes the proposed absorber an ideal basic building block for several applications ranging from sensing to indoor communication. Furthermore, the discussion section explains the potential applications of the proposed absorber for bio-sensing by filling the air gap with biological samples. [Display omitted] • A three-layer adjustable THz wave absorber is introduced in this paper. • The structure geometry is based on a combination of periodic graphene disks and their complementary pattern. • This configuration is modeled by passive circuit elements exclusively while full wave simulation is also performed. • A genetic-based algorithm is exploited to optimize design parameters numerical values including geometrical and stimulation values. • The potential applications of the proposed absorber is bio-sensing by filling the air gap with biological samples. [ABSTRACT FROM AUTHOR]

In this paper, the successful synthesis of bare molybdenum oxide (MoO 3) nanobelts using a one-step hydrothermal method without the use of surfactants is reported. Additionally, ZnO nanoflakes are synthesized through a green method, employing ginger extract, owing to the presence of phenolic compounds found in ginger, mainly gingerols , shogaols , and paradols. Furthermore, the fabrication of MoO 3 /ZnO nanocomposites using an uncomplicated and readily accessible ultrasonication method is presented. Also, the effects of hydrothermal reaction time (12, 24, and 36 h) and the molar ratio of MoO 3 nanobelts (NBs) to ZnO nanoflakes (2:1, 1:1, and 1:2) are investigated on the properties of synthesized MoO 3 nanostructures and MoO 3 /ZnO composites, respectively. The results declare that the optical and structural properties, morphology, and stability of the MoO 3 are influenced by hydrothermal reaction time significantly and the uniform MoO 3 nanobelts are obtained in a reaction time of 24 h. Also, the formation of nanocomposites with different ratios of MoO 3 nanobelt and ZnO nanoflakes by ultrasonication leads to forming uniform distributions of ZnO nanoparticles on the surface of MoO 3 structures. Indeed, the ultrasonication condition causes the transformation of the biphasic MoO 3 structure to a single-phase MoO 3 in the composites. Furthermore, the optical properties of MoO 3 nanobelts including the reflection especially in the UV region, and also the bandgap energies of the NBs are affected by providing the nanocomposites, and the bandgap energies change from 2.94 eV (bare MoO 3 nanobelts) to 3.18 eV (nanocomposites). The reasons for the phenomena are explained in the paper. These insights into the controlled synthesis of MoO 3 nanostructures and MoO 3 /ZnO nanocomposites pave the way for potential applications in fields such as advanced sensors, optoelectronics, and energy-efficient devices. [Display omitted] • Synthesis of MoO 3 nanobelts and consider the effects of hydrothermal reaction time. • Synthesis of ZnO nanoflakes (NFs) by a green method using the ginger extract. • Effects of NPs molar ratios on MoO 3 /ZnO nanocomposites provided by ultrasonication. • Transformation (bi-to single-phase MoO 3) in the composites. • Significant effects on optical properties including reflectance and bandgap energy. [ABSTRACT FROM AUTHOR]

This paper presents a high-sensitivity dual-open microchannel PCF-SPR refractometric sensor that was numerically analyzed using the Finite Element Method (FEM). A dual-open microchannel was created on both sides of the fiber to facilitate analyte infiltration and improve its detection performance. The microchannel of PCF was coated with gold plasmonic material to achieve practical sensing. The results revealed that the refractive index sensing range of the proposed refractometric sensor is between 1.37 and 1.43, with a highest amplitude sensitivity of 3743.64 RIU−1 and a wavelength sensitivity of 33000 nm/RIU. Additionally, it offers a maximum resolution of 5.56 × 10−6 RIU. All structure parameters, such as air-hole length, pitch, open-channel radius, and gold thickness, are optimized. The proposed sensor is a significant improvement in the detection of multiple analytes in bio-sensing applications. • This paper presents a high-sensitivity dual-open microchannel PCF-SPR refractometric sensor. • The refractive index sensing range of the proposed refractometric sensor is between 1.37 and 1.43. • High amplitude and wavelenght sensitivities of 3743.64 RIU−1 and 33000 nm/RIU respectively. Maximum resolution is 5.56 × 10−6 RIU. • The proposed sensor is an important improvement in the detection of multiple analytes in bio-sensing applications. [ABSTRACT FROM AUTHOR]

In the creation of nano- and macro-sized solid-state laser sources that emit light from pump light absorption, the main light-emitting component typically consists of rare earth or transition metal ions (optical centres) doped into an optically transparent solids in the form of a crystal or glass. This has led to countless demonstrations of laser systems and basic wavelength converters emitting over many octaves from the ultraviolet to the mid-infrared. Energy exchange from pump to laser via energy storage in the metal ion drives the process but, as the concentration of the ions increases, energy can transfer between the ions leading to a redistribution of the excited electronic states. Recently there has been very strong interest in exploiting energy transfer within nano-sized particles that are highly doped with rare earth ions. In this context and others, this paper sets out a basic review of the fundamental concepts related to energy transfer between excited and ground state ions with a view to assist in the basic understanding of energy transfer. With this understanding it is hoped that these important processes can be even further developed leading to higher efficiencies, higher output power and a wider range of emitted wavelengths. • A much-needed review of the basic theoryof energy transfer given the new optical materials being developed. • Provides a historical perspective and assembles some of the most important papers in energy transfer theory. • A completely re-written and updated version of a book chapter published in 2021 by the same author. • Offers areas for extension of the theory based on the recent progress in strongly pumped highly doped nanoparticles. [ABSTRACT FROM AUTHOR]

In this work, the development of a novel paper-supported ratiometric fluorescent sensing platform for amines detection and discrimination based on co-doped Tb3+ and Eu3+ silica film is reported. The sensor film was obtained by the sol-gel process, in a one-pot straightforward synthesis approach. After exposure to different amines, the resulting intensity ratio between Tb3+ and Eu3+ emission bands presents characteristic values that can be ascribed to the different amines. The higher emission intensity ratios were found for amines with the higher p K a values, as in the case of biogenic amines. The sensor can be stored for more than 120 days, keeping the capacity to detect and distinguish different amines. The prepared fluorescent probe was tested as a food freshness indicator in beef and tuna samples, where notable changes were observed during the food degradation. This proof-of-concept shows the capability of the developed sensor platform to be applied in the detection of multiple amines, and in daily and quality control operations by "naked-eye" inspection. [Display omitted] • Paper-supported co-doped Tb3+/Eu3+ silica film sensor for amine vapours detection. • Mechanism based on radiometric fluorescence of Tb3+ & Eu3+ emission intensities. • Different amine vapours produce distinguishable optical changes. • Biogenic amines lead to significant changes, useful for food freshness control. • Sensor platforms remain active and capable to discriminate amines after 120 days. [ABSTRACT FROM AUTHOR]

This paper presents the study and implementation of a modified Z-scan technique using a chopper to change the thermal load of the sample, while keeping the input peak irradiance constant. It was verified numerically and experimentally that by changing the frequency of the chopper and keeping the power of the laser beam constant, it is possible to vary the thermal load on the sample. This technique is illustrated under the study of the nonlinear optical (NLO) properties of nucleated Au–Pt metallic nanoparticles (NPs) by ion implantation. The nonlinear optical response was studied using the Z-scan. technique using a Ti:Sapphire laser with femtosecond pulses at a wavelength of 800 nm and a repetition rate of 76 MHz. By scanning the sample using the Z-scan technique it was It is possible to determine the refractive and absorbing contributions to the nonlinear response, in this case as a consequence of a high pulse repetition rate, cumulative pulse-to-pulse thermal effects occurred. Because of this, a modification of the Z-scan technique allowed to separate the resolution of the electronic and thermal contributions on the sample. • We present a technique that allows the determination of the electronic and thermal contributions to the third-order nonlinear optical response of a material, through the use of a variable frequency optical chopper in the z-scan technique. • We present a complete calculation of the heating produced in a sample by a femtosecond pulse train of finite duration. • The technique is illustrated by a study of the nonlinear response of a dual system of metallic nanoparticles (NPs) consisting of Au and Pt NP distributions embedded at different depths in a glass substrate, which was produced by ion implantation, using a femtosecond laser oscillator. • The technique allowed us to extract the thermal and electronic contributions to the nonlinearity of the sample studied, together with some thermal parameters. [ABSTRACT FROM AUTHOR]

Toxic industrial compounds as a global difficulty can adversely impact people's health and the environment which motivates studies on the interaction of light and metal oxide nanoparticles to treat the water through adsorption or photocatalysis mechanism by nanoparticles. In the paper, oxygen-vacancy-rich W 18 O 49 nanorods are successfully synthesized by a facile one-pot hydrothermal method using different molarities of hydrochloric acid (HCl) (2–12 M) as proposed candidates to treat the wastewater and solve the global difficulty related to treating the acidic water. The results declare that the change in acid molarity leads to noteworthy changes in the characteristic properties of the produced W 18 O 49 nanorods, and the lowest acid molarity (2 M) causes the formation of uniform and pure monoclinic W 18 O 49 nanorods with the high specific surface area (SSA) of 51.33 m2/g. Furthermore, the nanorods exhibit indirect and direct band gap energies in the range of 2.52–2.68 eV and 2.54–3.08 eV, respectively, as influenced by varying acid molarities (2–12 M). Furthermore, the impressive effects of acid molarity on the methylene blue removal efficiency of the nanorods under ultraviolet (UV) light are observed. The highest efficiency is obtained for W 18 O 49 nanorods synthesized using the acid molarity of 2 M which can be explained by its high SSA, small band gap energy, generation of a large number of electron-hole pairs, and its efficient charge separation. The efficiencies of water treatment reach up to 99 % and 99.5 % at pH of 7 and 5, respectively, which is an excellent achievement and leads to proposing the mentioned W 18 O 49 nanorods as an excellent candidate for treating wastewater and acid factory effluent which represents an appreciable breakthrough in addressing the issue. • Synthesis of oxygen-vacancy-rich W 18 O 49 nanorods (NRs) by hydrothermal method. • Considering the effects of HCl molarities on the synthesized NRs. • Significant effects on optical properties, including reflectance and bandgap energy. • Producing uniform and pure NRs with high SSA (51.33 m2/g) using low acid molarity. • High efficiencies of NRs in even acidic water treatment from dye under UV light. [ABSTRACT FROM AUTHOR]

Although Z-type heterojunction can significantly improve the catalytic performance of photocatalyst, there have been few reports on Z-type heterojunction about ZnSe. Therefore, it is meaningful to search for the Z-type photocatalyst in ZnSe to enhance its photocatalytic efficiency. ZnIn 2 S 4 , as a novel photocatalyst, its VB (1.72V) and CB (−0.71V) can match with ZnSe, indicating the potential formation of a Z-type heterojunction. Therefore, we hope to construct the ZnIn 2 S 4 /ZnSe photocatalyst by forming Z-type heterojunction to boost the photocatalytic activity of ZnSe. In this paper, ZnIn 2 S 4 /ZnSe heterojunction was prepared through hydrothermal method using ZnIn 2 S 4 , Zn(CH 3 COO) 2 ·2H 2 O and Na 2 SeO 3 as raw materials, and heated at 180 °C for 24 h. The optimum 30 % ZnIn 2 S 4 /ZnSe nanocomposites exhibit superior photocatalytic degradation towards Tc and OTC, with removal rates reaching 80 % and 74 % within 60 min, respectively, significantly higher than the degradation efficiency of pure ZnSe. And in the process of photodegradation for antibiotics, the most significant contribution rate are ∙O 2 − and h+, while ·OH plays a minor role. Herein, we have provided a good example for removing antibiotic residues by using ZnSe based Z-type heterojunction towards environmental remediation. Highly efficient ZnIn 2 S 4 /ZnSe photocatalyst have been constructed by hydrothermal hybridization of ZnIn 2 S 4 and ZnSe towards environmental remediation. [Display omitted] • A highly efficient Z-type photocatalyst ZnIn 2 S 4 /ZnSe was constructed by a facile method. • The catalyst show enhanced photocatalytic degradation for TC and OTC pollutants. • The photo-excited ·O 2 − plays a vital effect under the process of tetracycline degradation catalyzed by ZnIn 2 S 4 /ZnSe. • A good example for overcoming the limitations of pure ZnSe is provided. [ABSTRACT FROM AUTHOR]

Industries like textile, plastic, pulp, and paper produce dye-containing waste waters that have harmful effect on the environment as well as human health. This work presents a series of binary and ternary composites formed by reduced graphene oxide (rGO), silver phosphate (Ag 3 PO 4) and the nanocrystalline MOF, UiO-66(Zr). The composites exhibit the best of their catalytic features to achieve efficient photocatalysis to remove the model dye methyl orange (MO) from aqueous solution as well as dyes from a real industrial wastewater effluent. The composites were prepared under sustainable conditions, at room temperature. XRD characterization shows that the prepared MOF is one of the most nanocrystalline reported UiO-66(Zr), becoming even more nanocrystalline in the composite formation. Different physicochemical characterization techniques indicated the existence of such interaction. Thus, DRS-UV-vis spectroscopy makes clear the reduction of the band-gap of the composites compared with the individual components; the band intensity of the photoluminescence (PL) spectra is substantially reduced in composites, confirming the diminution of electron-hole recombination; and electrochemical impedance spectroscopy (EIS) shows that the electrodes modified with ternary composites present faster electron transfer ability. The selected composite rGO/UiO-66(Zr)/Ag 3 PO 4 exhibits high efficiency on the photodegradation of the model MO dye compared to the binary and single counterparts. It could be attributed to its high surface area, enhanced visible light absorption, efficient charge transfer process, as well as the synergetic effect between its components. A degradation mechanism is proposed based on the estimated band-gaps and on the scavenging study with strategically-chosen species. • Novel ternary rGO/UiO-66/Ag 3 PO 4 composite was prepared via simple solution method. • RGO/UiO-66(Zr)/Ag 3 PO 4 exhibited enhanced visible light photocatalytic activity. • Performance of the ternary nanocomposite is better than its single and binary rivals. • The ternary heterojunction degraded a real textile wastewater under visible light. [ABSTRACT FROM AUTHOR]

In this paper, we investigate and report the effects of Si4+/Al3+ (SiO 2 /Al 2 O 3) molar concentration ratio on the self-reduction process of Yb3+ to Yb2+ ions and upconversion (UC)-, visible (VIS)- emission spectra, direct optical bandgaps (DOB), indirect optical bandgaps (IOB) of Bin+/Ybm+, Er3+/Bin+, and Er3+/Bin+/Ybm+ (n, m = 3, 2) co-doped SiO 2 –Al 2 O 3 –MgO–TiO 2 (SAMT) magnesium aluminum silicate glasses. The valence states of the bismuth (Bi), and Ytterbium (Yb) elements in the raw materials mixture existing in the SAMT glass were determined using X-ray photoelectron spectroscopy (XPS) spectra analysis. With the increase of Al3+ molar concentration from 16 mol. % up to 20, 24, 28 and 32 mol. % corresponding to the Si4+/Al3+ (SiO 2 /Al 2 O 3) molar concentration ratio of 3.4, 2.5, 1.9, 1.5, and 1.2, the self-reduction process of Yb3+ to Yb2+ ions was enhanced and thus significantly affected the DOB, IOB, the intensities of UC-, VIS- emission spectra of Bin+/Ybm+, Bin+/Er3+, and Bin+/Er3+/Ybm+ (n = 2, 3) co-doped SAMT glasses under excitation of 473 nm, 808 laser diode (LD) and 980 nm LD. In addition, the CIE 1931(x, y) color coordinates for VIS- and UC- emissions spectra of Bin+/Ybm+, Bin+/Er3+ (n = 2, 3) co-doped SAMT under excitation of 473 nm and 808 nm LD are also calculated and determined in the CIE 1931(x, y) chromaticity diagram. • Effect of Si4+/Al3+ ratio on the self-reduction process of Yb3+ to Yb2+ ions were investigated. • XPS results determined existence of Bi3+, Bi2+, Yb3+, and Yb2+ ions in SiO 2 –Al 2 O 3 –MgO–TiO 2 glass. • CIE1931 for VIS, UC emissions of Bin+/Er3+/Ybm + under excitation of 473, 808 nm were determined. [ABSTRACT FROM AUTHOR]

In this paper, we present a detailed study of the temperature effect (0 − 100 ° C), on the plasmonic resonance and sensitivity of a surface plasmon resonance (SPR) to the medium detection refraction index change. We examine this SPR based on the Kretschmann multilayer configuration constituted by a BK7 prism, an Ag/Au bimetallic layer deposited on TiO 2 /SiO 2 and a BlueP/MoS 2 heterostructure monolayer. First, a simple numerical calculation is provided to analyze the temperature effect on the plasmonic resonance. The model take into account the dependence on temperature of the refractive index of different materials composing the investigated structures. The main idea is to show how the sensitivity of the SPR based sensor is influenced according to operating temperature which is critical parameter when considering bio-sensing applications. [Display omitted] • Study of the temperature effects on the BK7/TiO 2 /SiO 2 /Ag/Au/BlueP-MoS 2 /Sensing-medium biosensor. • Linear shift of plasmon resonance as a function of simultaneously measured temperature and refractive index. • The temperature coefficient sensitivity reaches as high as -1020.41 ppm/°C. • Obtained a sensitivity of 345.42deg/RIU, a value 139.9% higher than the conventional design. • The sensor is able to detect the analyte for a large variation of the refractive index, even at low temperatures. [ABSTRACT FROM AUTHOR]

The Fabry–Perot resonance within a microfluidic channel plays a crucial role in enhancing electromagnetic field strength, facilitating intensified interactions between terahertz waves and samples. In this paper, we introduce 2 THz microfluidic sensors based on Fabry–Perot resonance, each exhibiting dual resonant peaks for non-destructive detection. The first sensor features a periodic arrangement of three "I-type" structures, generating resonant peaks within the frequency range of 0.2–1.2 THz. These peaks correspond to absorption rates of 99.17 % and 99.51 %, with sensitivities of 100 GHz/RIU and 193 GHz/RIU, respectively. The second sensor also produces resonant peaks in the terahertz range, with absorption rates of 99.88 % and 99.94 % and sensitivities of 159 GHz/RIU and 226 GHz/RIU. After elucidating the physical mechanisms of both absorbers by analyzing the electric field and surface current distributions, we tested the dielectric constants of edible oils using the first sensor and evaluated the polarization insensitivity of the second sensor. These findings position the proposed sensors as versatile tools for biological detection and label-free detection even in trace amounts. • Introduced innovative THz microfluidic sensors with Fabry–Perot resonance to overcome water absorption issues in liquid detection. • Achieved exceptional sensitivities and Q-factors in two sensors, enabling highly precise detection capabilities. • Designed a new sensor structure with 90° rotational symmetry, significantly enhancing sensitivity and reducing polarization issues. • Demonstrated practical applications with highly accurate detection of edible oils, showcasing the sensors' potential for diverse fields. [ABSTRACT FROM AUTHOR]

In this paper, a very simple method was used to synthesize ligand-free luminous hydrogels doped with Tb3+ and Eu3+. The hydrogels exhibit red (615 nm), green (544 nm) and blue (425 nm) emissions derived from Tb3, Eu3+ and defects, respectively. Effective energy transfer from Tb3+ to Eu3+ is observed. We apply these ligand-free luminous hydrogels for temperature sensing for the first time. In surprise, the relative sensitivities are all very high (>2 %/K) by using many kinds of fluorescence intensity ratios. In addition, with the increase of temperature, the emission color of the samples changes significantly (from orange-red to blue) which can be applied for visual temperature sensing. The above results infer that the ligand-free luminous hydrogels can be used as an eco-friendly visual temperature sensing material. • Temperature sensing of ligand-free luminous hydrogels is reported firstly. • High sensitivities are obtained by using many kinds of FIRs. • Emissions color changes sharply with temperature for visual temperature sensing. • These hydrogels can be made into flexible transparent films for wearable devices. [ABSTRACT FROM AUTHOR]

The paper presents a synergetic and comprehensive investigation into γ-radiation shields properties on SiO 2 α-cristobalite subject varying external pressures (0

Flexible Perovskite Solar Cells (f-PSCs) are made on an ITO-coated PET substrate. Sn O 2 has been used as a transparent inorganic electron transporting layer (ETL), PEDOT: PSS as an organic hole transporting layer (HTL), and C H 3 N H 3 Pb I 3 as a perovskite absorbing layer. Two configurations of the device structure have been formed, one is normal structure ITO/PET/ Sn O 2 /C H 3 N H 3 Pb I 3 /PEDOT: PSS/Ag (n-i-p) and the other is inverted structure ITO/PET/PEDOT: PSS/C H 3 N H 3 Pb I 3 / Sn O 2 /Ag (p-i-n). An antisolvent (i.e. ethyl acetate) has been used to control the surface morphology of the perovskite layers during fabrication of f-PSCs. Applying antisolvent in perovskite improves carrier mobility, transport properties, and higher power conversion efficiency (PCE) achieved. This study focuses on the effects of series (R s) and shunt resistance (R s h ) of f-PSCs on photovoltaic parameters while controlling the surface morphology of perovskite films applied on both structures. The study examines the behaviour of f-PSCs with and without the use of an antisolvent. For normal structure, PCE is found at 11.34 % for f-PSCs with antisolvent and 7.96 % for f-PSCs without antisolvent. On the other hand, inverted structures show PCE 10.36 % and 7.46 % for f-PSCs with and without antisolvent, respectively. PCE has been calculated for the f-PSCs by bending the samples about 3 0 o angle and about 20 % decrease in PCE has been found. The oddity of this work is to estimate the series and shunt resistant for f-PSCs and find the cost-effective control of these parameters by controlling interfacial defects. [Display omitted] Flexible Perovskite Solar Cells (f-PSCs) are made on an ITO-coated PET substrate. Sn O 2 has been used as a transparent inorganic electron transporting layer (ETL), PEDOT: PSS as an organic hole transporting layer (HTL), and C H 3 N H 3 Pb I 3 as a perovskite absorbing layer. Two configurations of the device structure have been formed, one is normal structure ITO/PET/ Sn O 2 /C H 3 N H 3 Pb I 3 /PEDOT: PSS/Ag (n-i-p) and the other is inverted structure ITO/PET/PEDOT: PSS/C H 3 N H 3 Pb I 3 / Sn O 2 /Ag (p-i-n). An antisolvent (i.e. ethyl acetate) has been used to control the surface morphology of the perovskite layers during fabrication of f-PSCs. • The article shows effect of series (R s) and shunt resistances (R s h ) on solar cell parameters to enhance the photovoltaic performance of f-PSCs. • Single diode model has been employed to analyzed the results. • Better morphology has been achieved by using antisolvent. This paper also explains the effect of series (R s) and shunt resistances (R s h ) on morphology. • The flexible hybrid heterostructure PSCs shows PCE 11.34 % with antisolvent. [ABSTRACT FROM AUTHOR]

This paper presents the effect of Bi 2 O 3 on physical, thermal, structural, mechanical, optical, and radiation shielding properties of borate-based glasses having a composition (60-x)B 2 O 3 –25Na 2 O–13BaO-2Gd 2 O 3 -xBi 2 O 3 ; x = 0, 5, 10, 15, and 20 mol%. XRD analysis confirms the amorphous structure of the prepared glasses. As Bi 2 O 3 content increases from 0 to 20 mol%, density of the glasses increases from 2.729 to 3.896 g/cm3, and molar volume rises from 30.947 to 42.017 cm3/mol. The glass transition temperature (T g) of the samples decreased with Bi 2 O 3 content. FTIR analysis reveals the presence of BO 3 , BO 4 , BiO 3 , and BiO 6 structural units in the prepared glasses. Optical absorption studies indicate a decrease in band gap energy from 3.006 to 2.573 eV for indirect transitions implying non-bridging oxygen atom formation and this inference is supported by both physical and FTIR results. The elastic parameters, derived from Makishima-Mackenzie model decreased with increased Bi 2 O 3 concentration suggesting a reduction in mechanical properties. The mass attenuation coefficient (μ m), determined through experimental measurements and using Phy-X/PSD software, yielded closely aligned values. Other shielding parameters such as half-value layer (HVL), mean free path (MFP), and effective atomic number (Z eff) were also calculated. The glass containing 20 mol% Bi 2 O 3 exhibited a significant gamma-ray shielding potential due to its high μ m value, (0.1260 cm2/g at 0.511 MeV and 0.0960 cm2/g at 0.662 MeV) and Z eff together with low HVL and MFP. A Comparative analysis of the μ m values for the present glasses and that of other glasses containing Bi 2 O 3 is also presented. • Glass samples of the composition (60-x)B 2 O 3 –25Na 2 O–13BaO-2Gd 2 O 3 -xBi 2 O 3 ; x = 0, 5, 10, 15 and 20 mol% have been successfully prepared by melt-quenching technique. • The addition of Bi 2 O 3 in the glass system improves the density, molar volume and gamma radiation shielding properties. • The study elucidates the structural modifications of borate-based glasses imparted by the Bi 2 O 3 doping. • The non-toxic and environmentally friendly characteristics of our crafted glass samples present a practical solution for gamma shielding applications. [ABSTRACT FROM AUTHOR]

Solid-state photoluminescence materials have come out as an emergent material for their versatile optoelectronic applications. In the present contribution, a novel fluorescent probe, HMNS has been introduced which exhibits bright orange color photoluminescence when exposed to a 365 nm UV lamp and with a few drops of dimethyl sulfoxide (DMSO), it can be used as photoluminescence security ink. Further, HMNS is utilized for quickly and accurately detecting Al3+ ions in a water-DMSO (1:1, v/v) media displaying A l3+ ions-triggered aggregation-induced emission (AIE). Scanning electron microscopy and dynamics light scattering investigations revealed that HMNS from A l3+ ions triggered flower-shaped nano-luminogen. Probe HMNS can detect Al3+ ions within μM range and also the probe binds with Al3+ ions under physiological pH. The reaction time to Al3+ ions is only a few minutes (around 6–7 min). The development of J-aggregates and chelation-enhanced fluorescence (CHEF) in the water-DMSO (1:1, v/v) media may be responsible for the AIE behavior. Additionally, using the Al3+ ions triggered HMNS nano-luminogen could be used as a "marker-ink" which could be used as printing material to decipher secret data under UV light. Also, to determine its reversibility and reusability, the tested paper was washed with a PO 4 3− ions solution. A notable decrease in the code's intensity indicates that this material can be used repeatedly. Moreover, the probe is suitable for on-site identification when employed in test strips with better Al3+ ions selectivity. We have also used a smartphone-based method to demonstrate the usefulness of HMNS for the immediate quantification and detection of Al3+ ions. In light of this, probe HMNS is a trustworthy on-site monitoring fluorescence probe that can accurately identify Al3+ and PO 4 3− ions successively even when some other metals and anions compete. A solid-state brighter and greenish-yellow light emitting Al3+ ions-triggered flower-shaped Nano-luminogen for cascade detection of Al3+ and PO 4 3− ions embracing from electron donor-acceptor based dyad. [Display omitted] • A novel fluorescent probe, HMNS has been introduced which exhibits solid-state bright orange color photoluminescence. • It can be used as photoluminescence security ink. • Al3+ ions directed flower-shaped nano-luminogen is been fabricated which emits greenish-yellow luminosity. • Al3+ ions triggered HMNS nano-luminogen could be used as a "marker ink". • A smartphone-based method has been demonstrated for the immediate quantification and detection of Al3+ ions. [ABSTRACT FROM AUTHOR]

The known two-dimensional material MXene comprises carbide, carbonitride, and nitride. MXene processes are hydrophilic in addition to high electrical conductivity, thermal conductivity, flexibility, Young's modulus, fracture toughness, etc. The present work synthesizes a thermodynamically stable titanium-based MXene using HF etchant at low temperatures. Also, the paper manifests how the functional group affects the conducting nature of MXene. The structural properties of synthesized MXene are examined using XRD patterns, where the shift in the (002) arises. This indicates the successful formation of MXene. The electron microscopy of MXene is done using FESEM and HRTEM, which shows the layered structure of MXene thickness ranging from 5 nm to 8 nm along with EDX spectra showing the pure form of MXene with F, O and OH as the termination groups which is further confirmed by Raman spectroscopy and FTIR spectroscopy. The optical behavior is then examined using UV–Vis spectroscopy, and a large bandgap of symmetric MXene is observed, i.e., 1. 1 eV , due to the addition of a functional group at the surface of the MXene nanosheet. This demonstrates the semiconducting nature of MXene and the small particle size. Photoluminescence (PL) and Zeta-potential were also used to analyze the excellent stability of MXene after the material was confirmed, and the results indicate the green–yellow emission of the material. This prudent the thermally-stable MXene over the period both before and after 20 days. The electrical properties were then examined through current–voltage measurement, which predict the semiconducting nature of MXene. Consequently, the material can be used in numerous energy and optoelectronic applications. [Display omitted] • The synthesis of the MXene nano-material has been successfully achieved, as confirmed through various characterization techniques. • An enhancement in the band gap of MXene is observed at 1.1 eV due to the addition of a surface functional group confirmed from FTIR spectroscopy when undergoing UV-Vis characterization. • The synthesized MXene photoluminescence is done, showing exceptional stability for 20 days. • The current–voltage measurement analyses show better electrical conductance of MXene. [ABSTRACT FROM AUTHOR]

The excellent visible light photocatalytic activity of bismuth-based photocatalysts has attracted the interest of many scholars at home and abroad. In this paper, rare earth (Sm, La, Ce, Eu) doped Bi 2 WO 6 photocatalysts were prepared by a one-step hydrothermal method using bismuth nitrate and sodium tungstate as precursors. The microstructures and spectroscopic performances of prepared materials were investigated utilizing characterization methods, such as XRD, XPS, UV–vis, TEM, and N 2 adsorption-desorption, etc., and the effluent removal performances were studied by using rhodamine B as a simulated degradation dye and the photodegradation mechanism was investigated in combination with DFT calculations. XRD indicates that the rare earth doping leads to the lattice distortion of the (131) crystal surface of Bi 2 WO 6, and the relative amount of distortion is directly proportional to the photocatalytic activity; UV–vis spectra show that the absorption edge of Bi 2 WO 6 is obviously red-shifted with the rare earth doping, and N 2 adsorption-desorption curve show that the doped rare earths make the specific surface area of the sample effectively increased. Moreover, XPS spectrum suggests that the doped rare earth Ce and Eu often exist in the form of metastable oxidation states, and the transformation between Ce3+/Ce4+ and Eu2+/Eu3+ oxidation states is easy to form impurity energy levels between Bi 2 WO 6 , which make the energy level significantly enriched to broaden the absorption range and reduce band gap width of the material. DFT calculations further indicate that the rare earths successfully replace Bi sites. One of the main reasons for the improvement of photocatalytic activity is that rare earth doping is easier to replace Bi sites, leading to increased relative aberration; another one is that the arrangement of E VB and E CB in the photocatalytic mechanism is type-II, which contributes to red-shift of absorption edge and effective separation of electron-hole pairs in the photocatalytic process, thus improving the photocatalytic activity. • The doping of rare earths causes the light absorption edge of Bi 2 WO 6 to be red-shifted, resulting in the forbidden bandwidth becoming narrower and more visible light can be absorbed, to produce more photogenerated electron-hole pairs. • The rare earths Ce and Eu can effectively release electron acceptors to capture photogenerated electrons from the valence band to the conduction band and promote the effective separation of photogenerated electrons and holes. • After doping rare earth, the lattice distortion of Bi 2 WO 6 leads to smaller grain size and larger specific surface area, which helps the rapid migration of photogenerated electron-hole pairs to the surface to participate in the photocatalytic reaction. • DFT calculations show that doped rare earths are prone to form spatial structural defects, thereby increasing the specific surface area and further improving the photocatalytic performance. [ABSTRACT FROM AUTHOR]

The paper presents data on the study of optical absorption, photoluminescence and EPR of lithium-sodium tetragermanate crystals (LiNaGe 4 O 9) doped with Mn ions. Optical spectra were measured in the range 11000–45000 cm−1 and temperatures 77–300 K. They are attributed to manganese in the +4 charge state. From the analysis of optical spectra, the crystal field strength Dq = 2175.2 cm−1 and Racah parameters A = 4065 cm−1, B = 813 cm−1, C = 3239 cm−1 were determined for the Mn4+ ions. The value of the Huang-Rhys factor S FHR = 17.56 indicates a strong electron-phonon interaction of the Mn4+ ion. The presence of Mn4+ ions was further confirmed by measurement of EPR spectra at microwave frequencies 8.9 and 320 GHz. EPR data show that Mn4+ ions occupy two structurally nonequivalent lattice sites with the formation of two Mn4+ centers: Mn1 and Mn2. From the angular dependences of the EPR spectra, the components of the g factor and the hyperfine interaction tensor A , the parameters of the axial D and rhombic E crystal field were determined for both centers. The axial constant D is large for both centers: 0.644 and 0.560 cm−1, respectively. Analysis of optical and EPR spectroscopic data testifies that Mn4+ ions replace the Ge4+ ions in oxygen octahedrons within the host. Structurally nonequivalent centers are attributed to manganese ions located in undistorted lattice sites (Mn1) and in sites perturbed by the Li Na antisite defect (Mn2). • Optical absorption, photoluminescence and EPR are studied in Mn-doped LiNaGe 4 O 9 crystal. • It is shown that Mn4+ ions replace the Ge4+ ions in oxygen octahedral complexes within the host. • Models of two structurally nonequivalent Mn4+ centers in LiNaGe 4 O 9 lattice are proposed. • All crystal field parameters of Mn4+ centers are determined. [ABSTRACT FROM AUTHOR]

In this paper, silver nanowires (Ag NWs) were initially synthesized by the polyol synthesis method. A simple hybridization of silver sulfide (Ag 2 S) and silver was achieved by simply mixing as-prepared Ag NWs with different concentrations of Na 2 S aqueous solution (0.01 and 0.001 M). To study the properties of the nanomaterials, Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), energy dispersive x-ray spectroscopy (EDX), X-ray diffraction (XRD), Photoluminescence (PL) spectroscopy and UV–Visible (UV–Vis) spectroscopy were used. The ion exchange method was used to create Ag–Ag 2 S–CdS hybrid nanocatalysts. There has been no research further info on the degradation of methylene blue (MB) by an Ag– Ag 2 S–CdS nanocatalyst in the three environments (acid, neutral, alkaline). The MB dye was degraded for various minutes (min) in different pH degrees under the influence of sunlight using Ag–Ag 2 S–CdS. As a result of the experiments, the degradation efficiency of MB dye increased from 12.47 % to 57.02 % in the neutral, 40.58 %–80.08 % the in alkaline, and 91.87 %–97.92 % in the acid environment as time passed. The kinetics of the degradation process in each of the three settings was examined, and it was found that the neutral environment's photodegradation rate is a single value of 0.0029. This value varied depending on the time in a neutral and alkaline environment. As a result, the rate of degradation in the alkaline environment for the 60 min was 0.0071 (60–180 min), then 0.001 (120–300 min). The first degradation rate in an acidic environment was 0.0085 (60–120 min), then 0.0016 (120–300 min). • New type 1 D structured Ag–Ag 2 S–CdS hybrid NWs were synthesized. • Newly synthesized Ag–Ag 2 S–CdS NWs was used as a photocatalyst in 3 environments (neutral, alkali and acidic) and its effectiveness was analyzed. • The degradation efficiency increased from 12.5 % to 57.0 % in the neutral, 40.6 %–80.1 % the in alkaline, and 91.9 %–97.9 % in the acid environment under the influence of sunlight. • The neutral environment's photodegradation kinetics is a single value of 0.0029. The rate of the degradation in the alkaline environment for the 60 min was 0.0071 (60–180 min), then 0.001(120–300 min). The first degradation kinetic in an acidic environment was 0.0085 (60–120 min), then 0.0016 (120–300 min). • These circumstances (acidic environment and newly created Ag–Ag 2 S–CdS nanocatalysts) can serve as a model for efficient and affordable wastewater treatment. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) that utilize natural dyes have garnered interest due to their low cost, eco-friendly manufacturing process, and competitive photovoltaic performance. However, their efficiency and stability issues have hindered their widespread implementation. To enhance their performance, this paper proposes a novel approach of modifying the photoanode with carbon dots (CDs) to align the band gap for easier carrier collection. The material properties were thoroughly characterized by examining their structural, morphological, optical, and electrical properties. In this study, titanium dioxide (TiO 2) was synthesized using the microwave-assisted solvothermal method, while nitrogen-doped CDs derived from Citrus medica fruit juice were prepared using a simple hydrothermal treatment. Three sets of Natural Dye Sensitized Solar Cells (NDSSC) devices were created using co-activated photoanode (CD/TiO 2) and unmodified photoanode (TiO 2) with Platisol T/sp coated ITO serving as the counter electrode. Hibiscus (Hibiscus rosa-sinensis) and Onion (Allium cepa) peel extracts were utilized as sensitizers and Iodolyte HI-30 as the electrolyte. The most efficient device attained an efficiency of 3.5 % with Voc = 0.81 V and Jsc = 6.57 mA/cm2. This marks the highest efficiency reported using Hibiscus as a sensitizer with the current configuration, accompanied by prolonged device stability. This study showcases the potential of Citrus medica-derived nitrogen-doped CDs in achieving durable device stability. [Display omitted] • Synthesis of TiO 2 using a microwave-assisted solvothermal method for DSSC photoanode application. • Modification of the photoanode with carbon dots derived from biomass. • Enhancement of photovoltaic parameters through a co-activation strategy. • Utilization of natural sensitizers for cost-effective and environmentally friendly DSSC fabrication. • Improved device stability through the use of carbon dot-modified photoanodes. [ABSTRACT FROM AUTHOR]

This paper describes the production and characterizations of reduced graphene oxide-zinc oxide (rGO-ZnO) nanocomposites fabricated via hydrothermal approach. Firstly, rGO powder was produced via modified Hummers' method and ZnO nanoparticles using chemical co-precipitation. The nanocomposites structural, microstructural and optical characteristics were determined using X-ray diffraction (XRD), infrared spectroscopy (FTIR), Raman spectroscopy and Ultraviolet–visible (UV–Vis) spectroscopy. The findings demonstrated the effective synthesis of rGO-ZnO nanocomposites with evenly distributed ZnO nanoparticles on the surface of reduced graphene oxide sheets. rGO-ZnO nanocomposites with different concentrations ratio rGO:ZnO in composition of 10:0. 7.5:2.5, 5:5, 2.5:7.5, and 0:10 (weight percentage) were formed. An average crystallite size (D avg) was observed to be decreasing with an increasing concentration of ZnO in to rGO from ∼13.96 nm to ∼21.36 nm which is supported by Williamson-Hall (W–H) extrapolation. The FTIR spectra showed the functional groups belongs to intrinsic and extrinsic vibrations v 1 and v 2 at ∼410 cm−1 for rGO and metal‒oxygen (Zn–O) stretching vibrations ∼400 cm−1 to ∼500 cm−1 for rGO-ZnO nanocomposites. On rising ZnO content in the rGO-ZnO nanocomposites, a slight variation in band positions was caused due to the microstructural changes. Raman spectroscopy revealed certain peaks (D, G, for rGO ; E 2 , A 1 (TO), LO for ZnO) in various compositions. The research demonstrates how the composition of a material affects its vibrational characteristics, which is crucial for customizing the material for certain applications. The optical energy band gap of rGO-ZnO 75 % was recorded to be ∼4.94 eV, and highest for rGO with 5.44 eV. The optical energy band gap decreased from 5.44 eV to 4.94 eV. This decrease can be attributed to the influence of the smaller crystallite size and fluctuations in microstructural properties caused by the rGO-ZnO nanocomposite. The obtained rGO-ZnO nanocomposites can be utilized for opto-electronic device applications. • Synthesis of reduced graphene oxide (rGO) via modified Hummer method. • Fabrication of rGO-ZnO nanocomposites via Hydrothermal approach. • Williamson-Hall (W–H) analysis for average crystallite size determination. • Tailoring of micro-structural and optical characteristics through different composition of rGO-ZnO. • Fabricated rGO-ZnO nanocomposite can be utilized for opto-electronic device applications. [ABSTRACT FROM AUTHOR]

In this paper, one-dimensional nonlinear photonic crystals (NPCs) composed of alternating layers of yttrium iron garnet ferrite and strontium barium niobate crystals with opposite polarization directions are proposed. Through theoretical analysis, this structure can be utilized for second harmonic generation (SHG) with significantly enhanced second harmonic conversion efficiency (SHCE). The multiple reflections and interference effects of linear and nonlinear electromagnetic waves are taken into account, and the transfer matrix method (TMM) is employed to calculate the field distribution of the fundamental wave (FW) and second harmonic wave (SHW), as well as the SHCE. In particular, the TMM for SHW with angles is derived. In such NPCs, by modulating the linear and nonlinear optical parameters and optimizing the periodic thickness of the NPCs, high SHCE and angle sensitivity are achieved. It is demonstrated that the SHCE can be significantly enhanced when both the FW and SHW are tuned to the edge of the photonic band gap. In addition, this article also discusses the effects of incident wave angle, incident wave intensity, and applied magnetic field intensity on the SHCE. The study found that when the incident wave is at 0°, incident wave intensity is 3.9088 × 105 W/m2, and an external magnetic field of 1 T is applied, SHCE can exceed 20 %. With changes in the aforementioned external parameters, the thickness of the NPCs does not need to be altered to achieve the maximum SHCE. This indicates its strong tuning capability and wide range of potential applications. • The NPCs can effectively enhance the conversion efficiency of second harmonic wave. • The NPCs exhibit magneto-optical tunability by adjusting the magnetic field intensity and light intensity. • The NPCs exhibit angular sensitivity at different incident angles. • The NPCs exhibit nonreciprocity. • The NPCs provide new insights into the generation and calculation of second harmonic wave. [ABSTRACT FROM AUTHOR]

Silver consumption reduction is a current development in commercial tunnel passivated contact (TOPCon) crystalline silicon solar cell devices aimed at lowering the entire production cost of photovoltaic energy sources. It depends on the number of fingers and/or finger spacing (SP) on a cell area. In this paper, we analyze the possibility of minimizing silver use with respect to the dominant carrier transport mechanism. The carrier transporting mechanism, such as "pinhole" and/or "tunnel" models, is identified by examining temperature-dependent I–V characteristics of polysilicon passivating contact as a function of tunnel oxide (TO) thickness from 0.6 to 2.2 nm. Thermal oxidation was used to produce ultrathin TO films (0.6–2.2 nm) with temperature and gas ratio controlled. We find that the "pinholes" transport mechanism prevails when the TO thickness exceeds 1.6 nm, whereas the "tunnel" mode dominates when the TO thickness is less than 1.4 nm. The pinhole density is critical in pinhole mode for increasing SP. It is found that low pinhole densities and thick TO thickness (more than 1.6 nm) are two of the primary causes of narrow SP in TOPCon devices, which need a considerable quantity of silver. The experimental TOPCon devices as a function of TO thickness show a considerable trade-off between open circuit voltage (V oc) and fill factor (FF). While V oc rises, FF drops as TO thickness increases. The mechanism is described. • The thickness of tunnel oxide (TO) contributes to selection of electrode finger spacing. • The relationship between TO thickness, electrode finger spacing, and dominant transport mechanism is discussed. • This work suggests ways to lower the cost of producing TOPCon solar cell systems by minimizing their silver consumption. [ABSTRACT FROM AUTHOR]

The design and synthesis of low-cost hydrogen evolution photocatalysts with high carrier separation capability and visible light responsiveness are key factors in increasing hydrogen production. In this work, zero-dimensional (0D) amorphous nickel boride (Ni x B) was synthesized using a reduction method. Subsequently, a 0D/2D amorphous Ni x B/ZnIn 2 S 4 S-scheme heterojunction was fabricated through electrostatic attraction. This heterojunction exhibited stronger visible light responsiveness and enhanced photogenerated carrier separation performance. The morphology, composition, elemental, structural, and light absorption capacities of the as-synthesized composites were researched by SEM, TEM, XRD, XPS, and UV–vis DRS. The ability to separate photogenerated carriers were evaluated through photoelectrochemical experiments. The hydrogen evolution rate of Ni x B/ZnIn 2 S 4 (2208 μmol h−1 g−1) increased 25 times than that of single ZnIn 2 S 4 in sacrificial solution, and the apparent quantum yield (AQY) at 400 nm was 14.25 %. This study gives evidence of the great preponderance of S-scheme heterojunction and multidimensional material co-construction in improving hydrogen precipitation. In this paper, well-designed and high-performance 0D/2D amorphous Ni x B/ZnIn 2 S 4 S-scheme heterojunctions were successfully prepared by a simple method, which exhibited a good photogenerated carrier separation ability and enhanced hydrogen reduction performance under the action of the built-in electric field. The hydrogen evolution rate of Ni x B/ZnIn 2 S 4 was 2208 μmol h−1 g−1 and 25 times higher than that of single ZnIn 2 S 4 under sacrificial solution. The apparent quantum yield (AQY) at 400 nm was 14.25 %. This work demonstrates the great potential of S-scheme heterojunction and multidimensional material co-construction in improving hydrogen precipitation. [Display omitted] • Ni x B/ZnIn 2 S 4 S-scheme heterojunction was synthesized by simple stirring method. • Ni x B/ZnIn 2 S 4 exhibits accelerated the separation of photogenerated carriers. • Ni x B/ZnIn 2 S 4 shows excellent photocatalytic hydrogen evolution properties. • Co-catalyst Ni x B is cheap and easy to obtain. [ABSTRACT FROM AUTHOR]

The detection limitations of surface-enhanced Raman spectroscopy (SERS) sensors largely depend on the nano tip structure, yet the methods for constructing it are often overly complex. Here, we introduce a method using successive ionic layer adsorption and reaction (SILAR) to synthesize silver nanoflowers (AgNFs) within and on the surface of soft cellulose filter paper. This synthesis relies on a redox reaction involving silver nitrate (AgNO 3) and ascorbic acid (AA), with no surfactants or additional agents utilized. Key synthesis parameters were investigated, such as the molar concentration of reactants and the number of synthesis cycles performed. As a result, the detection limit for rhodamine 6G (R6G) using SERS approached 10−11 M when deposited on the optimally synthesized AgNFs sample, yielding a corresponding enhancement factor of 8.9 × 108. The growth mechanism of AgNFs was analyzed by examining morphological changes over the initial five reaction cycles, and differences in X-ray diffraction (XRD) peak intensity ratios of (111) and (200) among the samples were considered. These findings pave a way for the development of high performance, Ag-based flexible SERS substrates. • Silver nanoflowers were successfully fabricated by successive ionic layer adsorption and reaction method for the first time. • The nanoflower structures can be tailored without the usage of any surfactant or agent. • The SERS detection limit for rhodamine 6G deposited on AgNF samples approached to 10−11 M. [ABSTRACT FROM AUTHOR]

The paper presents a study on the structural and optical properties of nickel (Ni) thin films in the shape of vertical columns obtained by using the glancing angle deposition method. The films are deposited onto glass substrates at a fixed deposition angle of 85° to the different thicknesses of 50 nm, 80 nm, 110 nm, and 140 nm. Field emission scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and high resolution transmission electron microscopy (HR-TEM) were utilized to analyze the morphological, chemical, and microstructural properties of the films. SEM and TEM analyses are showing well-defined columnar structures, where the increase in thickness leads to more porous films and larger column diameters. The results of the surface examination of the XPS confirm that metallic Ni is a major phase in the deposited structures, but all samples also exhibit a certain amount of oxide phases. The optical measurements of the effective dielectric function reveal that both real and imaginary parts are strongly influenced by the changes in the film thickness. The surface plasmon resonance (SPR) peak is significantly shifted from 585.6 nm, as obtained for a 50 nm thick film, to 1291.8 nm in the case of a thickness of 140 nm. The variation in SPR peak position can be related to the differences in the film's morphology, and it is attributed to the changes in the size of the formed Ni nanoparticles. Finally, the experimental results show that with increasing film thickness, the electrical resistivity decreases. Both optical and electrical properties are found to be determined by the growth mechanism, and they are discussed on the basis of the defect concentration of the films. [Display omitted] • Nickel vertical columns obtained by GLAD. • Deposition parameters influence the structural, optical and electrical properties. • SPR peak positioned in the IR part of the spectrum. • Electrical resistivity decreases due to decrease of defect density. [ABSTRACT FROM AUTHOR]

The use of Faraday isolators in high-power lasers is currently a high-priority research topic and terbium gallium garnet (Tb 3 Ga 5 O 12 , TGG) transparent ceramic is a magneto-optical material with great potential for applications in the visible and near-infrared ranges. In this paper, the effect of chemical composition adjustment on the microstructure and properties of Tb 3 Ga 5(1+x) O 12 ceramics (where x is the non-stoichiometric index corresponding to the percentage difference in the amount of Ga used in the synthesis with respect to its content in the stoichiometric compound) was investigated. Powders obtained from starting materials of different stoichiometry were found to have similar morphology. However, the relative densities of the ceramics after pre-sintering in air increase with increasing Ga content. After the HIP post-treatment, the optimal properties with an in-line transmittance of 78.5 % (1.5 mm thick) at 1064 nm, and the Verdet constant of the ceramics with x = 0.8 % reaches −134.1 rad T−1 m−1 at 633 nm. • Tb 3 Ga 5(1+x) O 12 nano-powders with different stoichiometric ratios were synthesized by reverse strike co-precipitation. • TGG transparent ceramics were prepared by air pre-sintering with HIP post-treatment. • The in-line transmittance of TGG ceramics varies noticeably with different stoichiometric ratios. • The optimal TGG ceramics reaches the in-line transmittance of 78.4 % at 1064 nm. • The Verdet constant of the optimal TGG ceramics at 633 nm is −134.1 rad T−1 m−1. [ABSTRACT FROM AUTHOR]