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In the current work, ZnO film (~ 143 nm) is deposited on the CMOS compatible Si substrate by using RF sputtering technique to form a p-n type heterojunction device and further, thin buffer layer of TiO2 (~ 52 nm) is inserted in between ZnO and Si to reduce the interfacial defects remarkably in ZnO/TiO2/Si bilayer heterojunction for UV/Visible sensing applications. Smooth interface, and highly crystallite qualities of TiO2-brookite and ZnO-hexagonal wurtzite phases are observed from atomic force microscopy (AFM) and Field-emission gun scanning electron microscopy (FEG-SEM) and X-ray diffraction (XRD), respectively. X-ray photoelectron spectroscopy (XPS) clarifies the chemical states of elements, which indicate a significant amount of the reduction in oxygen vacancies after insertion of the TiO2 thin layer. An enhanced absorption in UV region and slight red shift in emission are observed in UV-Visible spectroscopy and Photoluminescence (PL) plots for TiO2/ZnO bilayer heterojunction, and oxygen related complex defects are reduced due to TiO2 insertion. Finally, Current-voltage (I-V) measurements demonstrate the dark current reduction in ZnO/Si heterojunction with TiO2 incorporation and such heterojunction exhibits photovoltaic behavior under specific wavelengths (380 nm and 420 nm). A superior responsivity (0.17 A/W), detectivity (7.80 × 10¹³ Jones) with rapid response speed (< 1 s) at zero bias are achieved in the UV-A/Visible wavelength range for ZnO/TiO2/Si heterojunctions. The corresponding photo-carrier generation and transport mechanism are analyzed in detail by using corresponding energy band diagram. Therefore, all the results indicate that such TiO2 thin layer inserted ZnO/Si heterojunction may provide a cost-effective feasible design strategy for the development of interfacial defect less, self-powered wavelength selective UV/Visible detectors in recent future. [ABSTRACT FROM AUTHOR]

The responsivity of the photodetector (PhoD) schemes based on silicon (Si) is constrained by its narrow bandwidth, indirect bandgap, and high surface reflectivity. Advanced optoelectronic applications are expected from graphene (Gr) owing to its semimetal behavior (zero band gap, high conductivity), tunable Fermi energy level, and most importantly, low noise. The semimetal behavior of Gr indeed implies a zero bandgap, which can introduce noise in optoelectronic devices. However, it is important to note that noise in optoelectronic applications is typically characterized by the signal-to-noise ratio, rather than solely the noise level. The zero bandgap of Gr may indeed impact its responsivity in certain applications. Therefore, in this review the potential for mitigating noise by integrating Gr with non-zero bandgap semiconductors such as Si, Ge, and MoS2 is highlighted. This hybridization can lead to improved responsivity and lower noise levels in optoelectronic devices. Combining Gr with Si and forming a Gr-Si junction Schottky diode, bias-controlled PhoDs can be the outcome by controlling the high recombination rate of induced photoelectron. Two-dimensional (2D) materials provide PhoDs with high electron mobility, improving the performance of Si-based PhoDs thanks to their zero band gaps. Therefore, 2D Gr-Si PhoDs have demonstrated outstanding Schottky features. Moreover, edge-contacted 2D materials in general and 2D Grs, in particular, come up with enhanced photo-response and diminished related signal noises in PhoDs. This review addresses the most recent advances in photodetection schemes based on the Schottky junction occurring at the interface of different 2D/nanomaterials with Si (mostly from recent reports of the last three years) and focuses on the basics of their mechanism. Furthermore, the fundamentals of photodiodes are compared with those of phototransistors regarding the same constituent materials. [ABSTRACT FROM AUTHOR]

Polymers containing lactam structures play a crucial role in both natural biological systems and human life, and their synthesis, functions and applications are of utmost importance for biomimetics and the creation of new materials. In this study, we developed an efficient heterogeneous Pauson–Khand polymerization (h‐PKP) method for the controlled synthesis of main‐chain poly(γ‐lactam)s containing α, β‐unsaturated γ‐lactam functionalities using readily available internal alkynes and imines. The molecular weights of the resulting poly(N−Ts/γ‐lactam)s can be precisely controlled by adjusting the ratio of phenyl formate and nickel. These polymers exhibit high solid‐state luminescence and demonstrate rapid and sensitive dual responsiveness to light and acid stimuli. They further demonstrate strong reactive oxygen species (ROS) generation capability. The unique dual‐emission peaks observed in poly(N−H/γ‐lactam)s obtained through post‐treatment under acidic conditions demonstrate a mechanism of aggregation‐induced intermolecular excited‐state proton transfer specific to lactam structures. The efficient one‐pot synthetic method for poly(γ‐lactam) provides a novel strategy for constructing polymers with γ‐lactam structures in the main chain and the simple and efficient post‐modification method offer a versatile toolbox for functionalizing poly(γ‐lactam)s to expand their potential applications. [ABSTRACT FROM AUTHOR]

Polymers containing lactam structures play a crucial role in both natural biological systems and human life, and their synthesis, functions and applications are of utmost importance for biomimetics and the creation of new materials. In this study, we developed an efficient heterogeneous Pauson–Khand polymerization (h‐PKP) method for the controlled synthesis of main‐chain poly(γ‐lactam)s containing α, β‐unsaturated γ‐lactam functionalities using readily available internal alkynes and imines. The molecular weights of the resulting poly(N−Ts/γ‐lactam)s can be precisely controlled by adjusting the ratio of phenyl formate and nickel. These polymers exhibit high solid‐state luminescence and demonstrate rapid and sensitive dual responsiveness to light and acid stimuli. They further demonstrate strong reactive oxygen species (ROS) generation capability. The unique dual‐emission peaks observed in poly(N−H/γ‐lactam)s obtained through post‐treatment under acidic conditions demonstrate a mechanism of aggregation‐induced intermolecular excited‐state proton transfer specific to lactam structures. The efficient one‐pot synthetic method for poly(γ‐lactam) provides a novel strategy for constructing polymers with γ‐lactam structures in the main chain and the simple and efficient post‐modification method offer a versatile toolbox for functionalizing poly(γ‐lactam)s to expand their potential applications. [ABSTRACT FROM AUTHOR]

The growing demand for real-time ultraviolet (UV) monitoring calls for a simple, rapid, and low-cost strategy to prepare UV photodetectors (PDs). We prepare a wearable real-time UV PD based on hydrogenated titanium dioxide film synthesized by radio frequency atmospheric pressure plasma. The conductivity of our hydrogenated titanium dioxide is improved to 10.2 S cm−1, nine orders of magnitude higher than that of pristine titanium dioxide after 10 min plasma treatment. Plasma hydrogenation disrupts the surface crystal structure, introducing oxygen vacancies (OVs) that create self-doped titanium(III) and titanium(II) species. First-principles calculations indicate that the OVs raise the Fermi level of TiO2 and distort the lattice locally. Our optimized film has a distinctive periodic switching characteristic under intermittent illumination; its responsivity is good from 280 to 400 nm, peaking at 632.35 mA W−1 at 365 nm. The fabricated wearable sensor based on the optimized film effectively monitors the daily variation of ambient UV intensity in three typical weather types, transferring its data to a smartphone via Wi-Fi. [ABSTRACT FROM AUTHOR]

Organometallic halide perovskites have shown significant promise for applications in optoelectronics and photovoltaics in recent years. This research looks into the performance of bulk heterojunction-based photodetectors (PDs) based on the active layer of a CH3NH3PbI3:PCBM bulk heterojunction (BHJ). We assessed the impact of PCBM concentration in CH3NH3PbI3:PCBM BHJ on the electrical performance of the PDs. We found that the BHJ PD with a 4% PCBM concentration had the strongest capability to reject noise, as demonstrated by its superior ratio of photocurrent to dark current. Moreover, the PD with a 4% PCBM concentration in the active layer outperforms pristine CH3NH3PbI3-based PDs in terms of optoelectronic performance, showing greater responsivity and detectivity. The improved optoelectronic performance of BHJ PD is due to increased interfacial area, higher electron extraction and a decrease in traps and defects. The analysis of dark current–voltage curves reveals a significant reduction in charge recombination for BHJ devices, supporting the elimination of traps and defects by the inclusion of PCBM. The PD’s impedance study unveils that the incorporation of PCBM enhances charge transfer and effectively suppresses charge recombination, leading to enhanced optoelectronic performance. [ABSTRACT FROM AUTHOR]

Many hydrogel patches are developed to solve the pervasive and severe challenge of complex wound healing, while most of them still lack satisfactory controllability and comprehensive functionality. Herein, inspired by multiple creatures, including octopuses and snails, a novel muti‐functional hydrogel patch is presented with controlled adhesion, antibacterial, drug release features, and multiple monitoring functions for intelligent wound healing management. The patch with micro suction‐cup actuator array and a tensile backing layer is composed of tannin grafted gelatin, Ag‐tannin nanoparticles, polyacrylamide (PAAm) and poly(N‐isopropylacrylamide) (PNIPAm). In virtue of the photothermal gel‐sol transition of tannin grafted gelatin and Ag‐tannin nanoparticles, the patches exert a dual anti‐microbial effect and temperature‐sensitive snail mucus‐like features. In addition, as the "suction‐cups" consisting of thermal responsive PNIPAm can undergo a contract‐relax transformation, the medical patches can adhere to the objects reversibly and responsively, and release their loaded vascular endothelial growth factor (VEGF) controllably for wound healing. More attractively, benefiting from their fatigue resistance, self‐healing ability of the tensile double network hydrogel, and electrical conductivity of Ag‐tannin nanoparticles, the proposed patches can report multiple wound physiology parameters sensitively and continuously. Thus, it is believed that this multi‐bioinspired patch has immense potential for future wound healing management. [ABSTRACT FROM AUTHOR]

The poly[N,N-(dimethylamino) ethyl methacrylate] (PDMAEMA) macro-RAFT agent mediated dispersion polymerization of photo-responsive nitrobenzene-based monomer of o-nitrobenzyl methacrylate (NBMA) was performed and the polymerization kinetics and evolution of the block copolymer nanoparticles morphology during the RAFT dispersion copolymerization were investigated in detail. This dispersion RAFT polymerization underwent initial homogeneous polymerization at initial stage and then a subsequent stage of slowed heterogeneous polymerization occurred until the monomer conversion of the polymerization reaction is basically unchanged at about 50% at 24 h. The reason of deceleration of the second stage that is different from the second stage of acceleration for common monomer is discussed. The PDMAEMA-b-PNBMA nanoparticles were prepared by PDMAMEA-mediated RAFT dispersion polymerization, and the photo-response of PDMAEMA-b-PNBMA nanoparticles was also studied. [ABSTRACT FROM AUTHOR]

The nebulizer spray pyrolysis (NSP) technique is employed to analyze the effect of samarium doping on the structural, morphological, optical, and electrical conductivity in Bi2S3 thin films deposited on bare glass substrates by varying the doping concentration from 0 to 3 wt %. Further, their photosensing properties are also studied to utilize the prepared Bi2S3:Sm thin films for photo-detecting applications. The Bi2S3:Sm thin films are found to be in an orthorhombic structure. The data from X-ray diffraction are used to calculate the value of crystallite size, microstrain, and lattice parameters, as well as the volume of the unit cell. 2% Sm-doped Bi2S3 film exhibited a maximum crystallite size of 38 nm and a lower micro-strain value. FESEM micrographs of 2% Sm-doped film show well-defined larger grains. The optical band gap is found to vary between 2.02 and 2.26 eV when the Sm doping concentration is varied. These thin films' absorption is higher around the ultraviolet region of the electromagnetic spectra. The electrical properties exhibited an increase in photocurrent under illumination. A higher responsivity of 9.57 × 10–1 AW–1, detectivity of 1.97 × 1011 Jones, and external quantum efficiency of 309% are recorded for Bi2S3:Sm (2%) thin film. The response and recovery time of the Bi2S3:Sm (2%)-based photodetector are observed to be 1.6 and 1.8 s, respectively. These favorable characteristics of samarium-doped Bi2S3 thin films recommend its potential usage in low-cost, high-performance UV photodetectors. [ABSTRACT FROM AUTHOR]

This study presents the fabrication of Mg x Zn (100-X) O thin films (TFs) with Mg concentration levels (x) of 0.5 at%, 1.0 at%, 1.5 at%, and 2.0 at% on glass substrates using the novel laser-assisted chemical bath growth (LACBG) method, aimed at investigating their photo-response for potential UV photodetector applications. Utilizing a continuous wave semiconductor laser with a 444.5 nm wavelength, 1 W power, and 6 min of irradiation, the LACBG method successfully produced high-quality Mg-doped ZnO TFs. These films were deposited on glass substrates coated with silver (Ag) to serve as electrode contacts for constructing a metal-semiconductor-metal (MSM) UV photodetector. The structural, optical, and electrical properties of the TFs were thoroughly analyzed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to examine the crystal microstructures and surface morphologies, revealing vertically aligned hexagonal symmetrical sub-micro tubes. In contrast, energy dispersive X-ray (EDX) analysis confirmed successful Mg incorporation into the ZnO lattice. UV–visible absorbance spectra indicated a blue shift in the absorption edge and increased band gap energy from 3.24 eV to 3.67 eV with rising Mg content. The UV photodetectors, particularly those with 2.0 at% Mg-doped ZnO TFs, demonstrated significantly enhanced UV responsiveness attributed to optical confinement, high surface-to-volume ratio, and superior structural quality. Performance metrics for the 2.0 at% Mg-doped ZnO TFs included a responsivity of 10.60 A/W, external quantum efficiency of 34.10, specific detectivity of 2.25 × 107 Jones, noise equivalent power of 5.34 × 10−11 W, rise time of 86.9 ms, and decay time of 324.4 ms. These findings underscore the potential of Mg-doped ZnO TFs for high-performance UV photodetection applications. The novelty of this study lies in utilizing LACBG to achieve high-quality Mg-doped ZnO TFs, offering a cost-effective, low-temperature method that enhances UV photodetector performance. [Display omitted] • Developed Mg-doped ZnO nanotube films using a laser-assisted chemical bath growth (LACBG) method. • Analyzed the effects of Mg doping levels (0.5–2.0 at%) on structural, optical, and electrical properties. • Observed a blue shift in absorption edge and increased band gap energy from 3.24 eV to 3.67 eV with higher Mg content. • Achieved significant UV photodetector performance with 2.0 at% Mg-doped ZnO TFs, showing a responsivity of 10.60 A/W. • Demonstrated detectivity of 2.25×107 Jones and low noise (5.34×10−11 W), showing potential for advanced UV photodetection [ABSTRACT FROM AUTHOR]

Thermally induced reversible up/down migration of poly(ionic liquid)s (PILs) in aqueous two‐phase systems (ATPSs) was achieved for the first time in this study. Novel ATPSs were fabricated using azobenzene (Azo)‐ and benzyl (Bn)‐modified PILs, and their upper and lower phases could be easily tuned using the grafting degree (GD) of the Azo and Bn groups. Bn‐PIL with higher GDBn could go up into the upper phase and Azo‐PIL come down to the lower phase when the temperature increased (>65 °C); this behavior was reversed at lower temperatures. Moreover, a reversible two‐phase/single‐phase transition was realized under UV irradiation. Experimental and simulation results revealed that the difference in the hydration capacity between Bn‐PIL and Azo‐PIL accounted for their unique phase‐separation behavior. A versatile platform for fabricating ATPSs with tunable stimuli‐responsive behavior can be realized based on our findings, which can broaden their applications in the fields of smart separation systems and functional material development. [ABSTRACT FROM AUTHOR]

Thermally induced reversible up/down migration of poly(ionic liquid)s (PILs) in aqueous two‐phase systems (ATPSs) was achieved for the first time in this study. Novel ATPSs were fabricated using azobenzene (Azo)‐ and benzyl (Bn)‐modified PILs, and their upper and lower phases could be easily tuned using the grafting degree (GD) of the Azo and Bn groups. Bn‐PIL with higher GDBn could go up into the upper phase and Azo‐PIL come down to the lower phase when the temperature increased (>65 °C); this behavior was reversed at lower temperatures. Moreover, a reversible two‐phase/single‐phase transition was realized under UV irradiation. Experimental and simulation results revealed that the difference in the hydration capacity between Bn‐PIL and Azo‐PIL accounted for their unique phase‐separation behavior. A versatile platform for fabricating ATPSs with tunable stimuli‐responsive behavior can be realized based on our findings, which can broaden their applications in the fields of smart separation systems and functional material development. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive supercapacitors have attracted broad interest in constructing self‐powered smart devices. However, due to the demand for high cyclic stability, supercapacitors usually utilize stable or inert electrode materials, which are difficult to exhibit dynamic or stimuli‐responsive behavior. Herein, this issue is addressed by designing a MoS2@carbon core‐shell structure with ultrathin MoS2 nanosheets incorporated in the carbon matrix. In the three‐electrode system, MoS2@carbon delivers a specific capacitance of 1302 F g−1 at a current density of 1.0 A g−1 and shows a 90% capacitance retention after 10 000 charging‐discharging cycles. The MoS2@carbon‐based asymmetric supercapacitor displays an energy density of 75.1 Wh kg−1 at the power density of 900 W kg−1. Because the photo‐generated electrons can efficiently migrate from MoS2 nanosheets to the carbon matrix, the assembled photo‐responsive supercapacitor can answer the stimulation of ultraviolet‐visible‐near infrared illumination by increasing the capacitance. Particularly, under the stimulation of UV light (365 nm, 0.08 W cm−2), the device exhibits a ≈4.50% (≈13.9 F g−1) increase in capacitance after each charging‐discharging cycle. The study provides a guideline for designing multi‐functional supercapacitors that serve as both the energy supplier and the photo‐detector. [ABSTRACT FROM AUTHOR]

Owing to the facile fabrication and surface modification, the cost-effective polymer nanopores are widely employed in unimolecular determination of biomacromolecules and selective sensing of small molecules, nanoparticles and biomarkers. However, the documented polymer nanochannels are generally microscale in length with low spatial resolution. We herein synthesized azobenzene side-chain polymer (Azo-PMA) and spin-coated on silicon nitride membrane to obtain a polymer film of nanoscale thickness for further nanopore generation via controlled dielectric breakdown (CDB) approach. The Azo-PMA nanopores demonstrate good ions transporting activities, pH tolerance and stability in high concentration of electrolyte with low ionic current noise. In addition, the azobenzene-containing polymer nanopores exhibit photo-response upon UV/Vis. light irradiation. The Azo-PMA nanopore devices are utilized for linear and quadruple nucleic acids discrimination, sensing of proteins with distinct shapes and sizes, as well as the single amino acid resolution with good capture rate and sensitivity. We established an unimolecular sensing platform using polymer nanopores for nucleic acids and proteins detection with good spatial resolution, which will be an addition for the nanopore-carrier material exploration and applications in potential genomics and proteomics with high spatiotemporal resolution and low cost. [Display omitted] • Established a polymer nanopore platform of <20 nm in length for unimolecular sensing with good spatial resolution. • Generation of Azo-PMA nanopore by CDB with good ionic conduction, pH tolerance and photo-response. • Good resolution of nucleic acids, proteins and amino acids with novel Azo-PMA nanopore devices. [ABSTRACT FROM AUTHOR]

In this present work, copper (II) sulfide (CuS) nanoparticles (NPs) were synthesized via co-precipitation [CuS(co-pr)] and solvothermal [CuS(solv)] methods. The structural, optical, and electrical properties of these materials were analyzed and compared. It was observed that the particle size and crystallinity varied depending on the synthesis method employed. Further, two individual metal-semiconductor junction devices based on CuS(co-pr) and (CuS(solv) were fabricated. Then the current vs. voltage (I–V) measurements were performed. The comparative study of the electrical parameters like photo response, rectification ratio, barrier height and ideality factor were performed between the two synthesized CuS NPs based devices. Under no light condition, the rectification ratio for CuS(solv) increased by 28 % more than that of CuS(co-pr). The photo response for CuS(solv) also enhanced by 146 %. For a better understanding of junction and carrier transport properties space charge limited current (SCLC) theory is incorporated. The interfacial resistance of the devices was studied by Nyquist plots obtained from the impedance spectroscopy and were also fitted by equivalent circuit model and explained the mechanism of charge transport through the Schottky interface. The transit time and carrier mobility were improved for CuS(solv) than CuS(co-pr). Thus, the solvothermally synthesized CuS-based device could be assigned as it possesses lesser number of lattice defects, better crystallinity and larger particle size along with its better film properties leading to better performance. [Display omitted] • Optical absorption edge of CuS(solv) shifted towards the longer wavelength than CuS(co-pr). • CuS NPs synthesized by solvothermal method exhibits improved charge transport and photo response over CuS(co-precipitation). • Fewer carrier recombination through M−S junction make CuS(solv) a better Schottky device over CuS(co-pr). • Lesser lattice defects and better thin film properties enhances performance of CuS(solv) based Schottky diode. [ABSTRACT FROM AUTHOR]

• Novel ATPSs were fabricated using Azo- and Bn-functionalized PILs. • The grafting degrees of Azo and Bn had significant effects on the phase separation of ATPS. • The upper/lower phases of ATPSs with CB[8] could be inverted by photo and thermo stimuli. • The phase separation of ATPSs was regulated by host–guest interaction for the first time. Smart aqueous two-phase systems (ATPS) have aroused tremendous interests in view of their tunable phase behaviors under various stimuli, and found many potential applications in the domain of separation. Herein, poly(ionic liquid)s (PILs), functionalized by benzyl (Bn) and azophenyl (Azo) groups, were prepared through a post-synthesis modification strategy. The as-fabricated ATPSs composing of Azo-PIL and Bn-PIL exhibited a photo- and thermo-responsive two-phase to one-phase transition. However, when the host molecule cucurbituril[8] urea (CB[8]) was introduced, the as-developed PIL-based ATPSs underwent a reversible upper and lower phases inversion behaviors, which could be tuned through light irradiation or heating treatment. The study revealed that both the grafting degree (GD) of Azo/Bn groups and the feeding ratio of CB[8] played a critical role in this switchable phase inversion behavior. In addition, the sensitive hydration ability of functional PILs to external stimuli accounted for the phase inversion behavior of ATPSs. Thereby, our finding offers a novel platform for adjusting the phase separation behaviors of ATPSs via host–guest interactions. [ABSTRACT FROM AUTHOR]

Stepwise assembly starting from a preassembled metalloligand is a promising approach to obtain otherwise unattainable silver nanoclusters, but hard to be intrinsically identified due to the lack of convincing evidence to justify such a process. Herein, hexagonal and rectangular Ag18 nanoclusters are constructed from the [Mo2O5(PTC4A)2]6− (H4PTC4A=p‐phenyl‐thiacalix[4]arene) metalloligand through stepwise assembly. The formation of the metalloligand is confirmed by electrospray ionization mass spectrometry, then assembled with silver ions to form two geometrically different Ag18 nanoclusters in different solvents. The cyclization from the metalloligand to [(Mo2O5PTC4A)6]12− can be realized without alcohols and otherwise blocked by them. The installation of this metalloligand not only provides comprehensive understanding of how the solvents regulate the silver nanocluster structures, but also brings new insights for the controllable ligand metallization and subsequent condensation. [ABSTRACT FROM AUTHOR]

Stepwise assembly starting from a preassembled metalloligand is a promising approach to obtain otherwise unattainable silver nanoclusters, but hard to be intrinsically identified due to the lack of convincing evidence to justify such a process. Herein, hexagonal and rectangular Ag18 nanoclusters are constructed from the [Mo2O5(PTC4A)2]6− (H4PTC4A=p‐phenyl‐thiacalix[4]arene) metalloligand through stepwise assembly. The formation of the metalloligand is confirmed by electrospray ionization mass spectrometry, then assembled with silver ions to form two geometrically different Ag18 nanoclusters in different solvents. The cyclization from the metalloligand to [(Mo2O5PTC4A)6]12− can be realized without alcohols and otherwise blocked by them. The installation of this metalloligand not only provides comprehensive understanding of how the solvents regulate the silver nanocluster structures, but also brings new insights for the controllable ligand metallization and subsequent condensation. [ABSTRACT FROM AUTHOR]

Magnetotactic bacteria (MTB) synthesize intracellular magnetic organelles, magnetosomes, which consist of magnetic crystals that are enveloped in a membrane. Magnetosomes are organized into a chain(s) and confer on cells a magnetic dipolar moment. This magnetic property allows MTB cells to align and swim along geomagnetic field lines, a movement referred to as magnetotaxis. Some MTB species change their swim direction in response to illumination by UV, violet and blue light. Here we analyzed the polarity of morphology, magnetism, and motion in Mediterranean multicellular magnetotactic prokaryotes, also called, magnetoglobules or MMP. The magnetoglobules were assembled from 60–80 cells into an asymmetric ellipsoidal morphology with a relative narrow and large end. They swam dominantly northward, parallel to the direction of the magnetic field, with the narrow-end as the leading side. In response to a reversal in the direction of the magnetic field, they aligned quickly along the magnetic field lines and kept swimming northward. Interestingly, under constant illumination, 385-nm UV light, magnetoglobules changed their swimming direction southward anti-parallel to the direction of the magnetic field, with the large-end as the leading side. The change from a northward to southward direction occurred along with an increase of swimming speed. A minimum of 35-mW/cm2 irradiance of UV light was sufficient to trigger the swimming re-orientation. UV radiation also triggered the unidirectional division of magnetoglobules. Together these results revealed a coordination of the polarity of magnetoglobule morphology, magnetic moment, and swimming orientation, in response to magnetic and optical stimuli. The UV triggered the reversal of magnetotaxis and magnetoglobule division indicating the ecological significance of light for multicellular magnetotactic prokaryotes. [ABSTRACT FROM AUTHOR]

Solid-stated smart polymers responsive to external stimuli have attracted much attention for potential application in the field of photoelectron devices, logic gates, sensor, data storage and security. However, it is a bigger challenge for polymers than that for small molecules in solid state to acquire stimuli-responsive properties, because polymers with high molecular weight are not as easy to change the packing structure as small molecules under external stimulation. Here, a D-A type alternating copolymer PTMF-o containing 3,4-bisthienylmaleimide (A unit) and fluorene (D unit) is designed and synthesized. Upon irradiation of sunlight, PTMF-o film exhibits a photo-response with the color altering from purple to colorless. It is attributed to the structure of copolymer transformed from ring-opening form (PTMF-o) to ring-closure form (PTMF-c), resulting from the oxidative photocyclization of 3,4-bisthienylmaleimide unit. Consequently, the ability of charge transfer (CT) from fluorene to 3,4-bisthienylmaleimide unit in PTMF-o can be easily weakened by light stimuli. PTMF-o film displays a WORM-type resistive storage performance for the strong CT. Interestingly, after exposure, the electrical memory behavior in situ transfers into FLASH type, due to weak CT in PTMF-c. PTMF-o film can also be employed as smart material to construct NAND and NOR logic gates by using light as input condition. The work provides a simple way to modify the electronic properties of polymers and realize stimuli-response in solid states. [ABSTRACT FROM AUTHOR]

• POPs functionalized by Azo and phosphonium units were fabricated for organic dyes removal. • Azo-POP exhibits extraordinary adsorption capacity towards anion dyes. • The removal efficiency of Congo Red (CR) could reach 100 % in 30 s. • The adsorption capacity of Azo-POP is photo-tunable. Adsorption has been recognized as a highly economical and feasible technique for the removal of organic pollutants from water. Thus, the search for novel and efficient porous adsorbents for water purification is a crucial and pressing task. Here, a new family of azobenzene- and phosphonium-functionalized porous organic polymers (Azo-POPs) were fabricated via a post-synthesis approach. By taking advantage of the photo-tunable transformation of Azo units, the adsorption behaviors of two isomers of Azo-POP, trans- Azo-POP and cis- Azo-POP, were examined. The results demonstrated that both of Azo-POPs exhibited extraordinary adsorption capacity and adsorption rate towards anionic dyes due to their porous structure, cation-charged and hydrophilic skeleton. However cis- Azo-POP afforded much more efficient adsorption performances. The removal efficiency of Congo red (CR) could reach 100 % in 30 s, and the maximum adsorption capacity was as high as 1376.8 mg g−1, surpassing most previously reported adsorbents. The pseudo-second-order rate constant of cis- Azo-POP was 16.9153 g mg−1min−1. Additionally, Azo-POP adsorbents could be easily regenerated and reused over five cycles without any loss of adsorption capability. Therefore, the study suggests a universal platform for the fabrication of functional POP materials, which will find great potential in the fields of industrial wastewater treatment and catalysis. [ABSTRACT FROM AUTHOR]

Photo-responsive mechanical actuator is a class of stimuli-responsive materials transferring light to mechanical energy through macroscopic transformation. To fabricate photo-responsive mechanical actuator, soft polymeric materials crosslinked with functional bridging structures are desired. Supramolecular interaction is a relatively common way to fabricate crosslinked materials due to its excellent self-assembly performance. And azobenzene and derivatives are ideal candidates of photo-responsive materials because of the unique photo-induced trans-cis isomerization. Here, a new kind of crosslinked materials based on supramolecular interaction between 4,4′-dihydroxyazobenzene and chitosan is reported. Under 355 nm irradiation, the macroscopic bending of polymeric materials occurs rapidly due to the photo-isomerization of 4,4′-dihydroxyazobenzene. Meanwhile, the photo-responsive mechanical actuator can also lift weight which is up to 200 times that of the actuator itself, and convert energy from light to mechanical work efficiently. This report suggests a new kind of photo-responsive actuator based on supramolecular interaction and may be helpful to contribute a theoretical basis to the design and synthesis of photo-responsive mechanical actuator suitable for large-scale manufacturing industrialization in future. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive fluorescent materials with aggregation‐induced emission (AIE) characteristics have attracted increasing attention owing to their advantages of bright fluorescence in the solid state and the ability to tune the structures and physicochemical performances in response to various stimuli. Among all the available external stimuli, light stands out, and has rapidly become a focus of research, because it offers green and remote triggering, noninvasive manipulation, high spatiotemporal resolution, and convenient tunable properties. Consequently, photo‐responsive AIE materials provide a fascinating strategy for constructing functional fluorescent materials. This review summarizes the recent advances in the fabrication of photo‐responsive fluorescent materials with AIE characteristics by grafting AIE fluorogens (AIEgens) into photochromic molecules. State‐of‐the‐art photo‐responsive AIE materials based on the inherent photochemical reactions of AIEgens are highlighted, and are classified and discussed according to the photochemical pathways, including photocyclization, photo‐isomerization, photodimerization, photo‐removal, and multiple photoreactions. Following this, the corresponding applications of photo‐responsive AIE materials in bio‐imaging, anti‐counterfeiting, photo‐patterning, photo‐release of chemicals or drugs, and photo‐controlled assembly and disassembly are introduced. Finally, the most promising directions for development and applications of photo‐responsive AIE materials are outlined and discussed. [ABSTRACT FROM AUTHOR]

Cubic perovskite oxides are attracting wide attention for applications in electronics and optoelectronics due to their high electronic mobility, however, realization of p -type conductivity in these oxides is still a matter. Barium stannate (BaSnO 3) is one of such materials, wherein low-amount of lanthanum-doping can induce an extremely high room-temperature electron mobility. In this work, anion-doping strategy was explored to realize the p -type conductivity in BaSnO 3 , and the underlying physics of transport was investigated. It is found that nitrogen substitution for oxygen can induce the p -type conductivity in BaSnO 3 thin films. By analyzing the temperature-dependent resistance and negative magnetoresistance data, Efros-Shklovskii variable-range hopping conduction is identified as the dominant transport mechanism in p -type BaSnO 3 thin films. Additionally, nitrogen-doped BaSnO 3 homojunctions exhibit good rectifying and photo-response properties. This study provides an alternative strategy for realizing the p -type conductivity in stannate-based perovskite oxides, and is helpful for designing the properties of stannate-based devices. [ABSTRACT FROM AUTHOR]

Enclosing the pesticide in a carrier and releasing it based on environmental stimuli is proved to be a viable strategy for addressing pesticide losses and mitigating environmental contamination. Here, an interpenetrating network (IPN) composite hydrogels (OMt/Alg/PNIPAm) with light and temperature responses was prepared by the incorporation of clay material, organo-montmorillonite (OMt), via the free-radical polymerization of N-isopropyl acrylamide (PNIPAm) and its crosslinking as well as ionic crosslinking reaction of sodium alginate (SA) with FeCl 3. The structure of OMt/Alg/PNIPAm was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermos gravimetric analysis (TGA) and rheometer. The hydrophobic pesticide λ-cyhalothrin (LC) was encapsulated in OMt and subsequently incorporated into the IPN structure of the composite hydrogels, ensuring the desirable mechanical properties, encapsulation efficiency and sustained release performances of the composite hydrogels. In addition, with the rising of OMt content, the IPN composite hydrogels exhibited a decrease in their swelling capacity, transparency, and temperature sensitivity. The OMt/Alg/PNIPAm with 9.0% OMt content displayed the highest loading rate for pesticides at 82.06% and the lowest release rate of pesticides at 3.90%. Furthermore, the IPN composite hydrogels possessed the ability to regulate the amount of pesticide release based on the variations in temperature and ambient light conditions. The resultant IPN composite hydrogels took advantage of the temperature responsiveness of PNIPAm, the light sensitivity of Fe3+-alginate hydrogel, and the adsorption capability of OMt, possessing great potentials in enhancing the utilization efficiency of hydrophobic pesticides through the development of effective and eco-friendly pesticide formulations. [Display omitted] • The intelligent OMt/Alg/PNIPAm with light and temperature response were prepared via IPN method. • The chemical crosslinking of PNIPAm and ionic crosslinking of SA achieved IPN composite hydrogels. • OMt was used to improve the mechanical property and drug-loading rate of the OMt/Alg/PNIPAm. • The OMt/Alg/PNIPAm could regulate the pesticide release in response to environmental stimuli. • The OMt/Alg/PNIPAm could be preferably used as potential hydrophobic pesticide carriers. [ABSTRACT FROM AUTHOR]

Quaternary (Ge 0.03 In 0.97)(Se 0.95 S 0.05) crystals, pivotal for advanced sensing applications, were successfully grown utilizing the direct vapour transport (DVT) technique. An integrated approach, encompassing scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDAX), explored the morphological and chemical composition of the as-grown crystals. The resulting hexagonal structure was confirmed via X-ray diffraction (XRD), while the Williamson–Hall model revealed a crystallite size and lattice strain. Impressively, the crystals exhibited a direct band gap of 1.03 eV. Comprehensive kinetic insights were gleaned from differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) curves, enhancing our understanding of the material's thermal behaviour. Electrical resistance studies, conducted as a function of temperature and vacuum pressure, underscored the intricate interplay between these parameters and the crystal's conductivity. Remarkable photo-response properties were meticulously evaluated under varying illumination intensities, showcasing crystals potential in photo-sensing applications. The crystal's exceptional capabilities extended to the realm of human respiration monitoring, where it facilitated the measurement of electrical currents across diverse breathing conditions. Photo-catalytic process was harnessed for environmental remediation, particularly for the degradation of methylene blue (MB) under visible light irradiation. Collectively, these findings position the (Ge 0.03 In 0.97)(Se 0.95 S 0.05) crystals as a compelling contender for versatile multi-sensing devices. • Sucessful Growth of (Ge 0.03 In 0.97)(Se 0.95 S 0.05) using direct vapour transport (DVT) technique. • The grown crystals were characterized through extensive characterization. • Study involves the photo-catalytic properties of the (Ge 0.03 In 0.97)(Se 0.95 S 0.05) crystals under visible light irradiation. • Investigation on Thermal stability of grown crystals by the TGA and DSC curves. • (Ge 0.03 In 0.97)(Se 0.95 S 0.05) crystals unique combination of properties, including high sensitivity and visible-light responsivity. [ABSTRACT FROM AUTHOR]

This work aims to study the photo-response of the fabricated silicon-based Al/PVP:ZnTiO 3 /p-Si photodiode (PD) in a wide range of illumination intensities. To make a metal-polymer/nanocomposite-semiconductor (MPS) PD, a thin film of PVP:ZnTiO 3 nanocomposite is deposited at the interface of the metal-semiconductor (MS) structure. Information regarding the preparation and manufacturing procedures is provided. Through the examination of the current-voltage (I–V) behavior, essential electrical properties such as leakage current (I 0), barrier height (Φ B0), ideality factor (n), series and shunt resistances (R s , R sh), energy-dependent interface states density (N ss), photocurrent (I ph), and photosensitivity (S) are acquired. The thermionic emission (TE) theory, along with the Norde and Cheung methods, is employed to calculate the parameters Φ B0 , n, and Rs. The values of Φ B0 and R s are decreased by raising the illumination intensity while the n value is increased. In addition, the illumination coefficient (α) and the value of Φ B0 in the ideal case are determined from the Φ B0 -P and Φ B0 -n plots. The efficiency (η) of the sample is calculated at each illumination intensity whose maximum value is 2.30 % at the intensity of 450 mW/cm2. The illumination-dependent photocurrent is investigated at the negative bias region that shows a good linear behavior in the ln(I ph)-ln(P) profile. The photosensitivity (S) of the fabricated PD is obtained as ⁓500 which is, compared with previous PDs. These findings demonstrate that the developed silicon-based MPS-type PD with a structure of Al/PVP:ZnTiO 3 /p-Si exhibits a good photo-response and can successfully replace traditional MS PDs in optoelectronic and photovoltaic applications. • A Si-based Schottky photodiode (PD) with a PVP:ZnTiO 3 interlayer is introduced. • The opto-electric response of the fabricated PD is measured under illumination. • The interface states density in the PD is reduced under illumination. • The efficiency of the PD is maximized at the illumination intensity of 450 mW/cm2. • The photosensitivity of the PD is higher than others introduced in literature. [ABSTRACT FROM AUTHOR]

Increasing the carrier concentration as well as carrier life time could be effective ways to increase the photoresponse of a photoconductive type photodetector. In this paper, layer-structure photodetectors have been fabricated by connecting CH 3 NH 3 PbI 3 film with and without electron transport layer (SnO 2 and SnO 2 /PCBM bilayer). We found that the electron extraction at the electron transport layer and MAPbI 3 interface will boost the photocurrent and responsivity, and faster electron extraction will result in a higher photocurrent improvement. At the same time, the closer is the distance of the interface to the photogenerated electron-hole pairs, the larger is the photocurrent enhancement. The largest photocurrent increasement is almost 3 times the initial value, which increases from 1.54 μA to 6.10 μA. Image 1 • Electron extraction from excited active layer boosts the photo-response of Au/CH 3 NH 3 PbI 3 /Au photodetector. • Higher electron extraction velocity, higher improvement in photo-response. • The closer is the photon generated electron and electron extraction layer, the higher is increasement in photocurrent. [ABSTRACT FROM AUTHOR]

Hybrid halide perovskites have emerged as pivotal optoelectronic materials due to their easy and cost-effective solution-based manufacturing processes. In this study, we have combined formamidinium lead bromide (FAPbBr 3) with buckminsterfullerene (C 60) to create the bulk heterojunction (BHJ) photoactive layer for solution-processed photodetectors. Remarkably, the FAPbBr 3 :C 60 BHJ-based photodetectors exhibited a substantial enhancement in optoelectronic performance, with the responsivity increasing from 0.87 A/W to 1.47 A/W compared to the pristine FAPbBr 3. This improvement can be attributed to the superior surface morphology and crystallinity of the FAPbBr 3 :C 60 BHJ thin film, which facilitated enhanced charge transport properties. Furthermore, the fabricated photodetectors demonstrated remarkable detectivity even at 0V, enabling self-powered operation. By employing the space charge limited conduction (SCLC) model, we were able to elucidate the dominant charge transport mechanism. At lower voltages, trap-free SCLC was identified as the primary mechanism, while traps governed charge transport at higher voltages. Additionally, we conducted impedance analysis to investigate the underlying factors contributing to the distinctive optoelectronic performance observed in the photodetectors. • Blended FAPbBr 3 with C60 to create the BHJ photoactive layer. • BHJ-based photodetectors exhibited a superior performance than pristine FAPbBr 3. • The PDs showed remarkable detectivity even at 0V, enabling self-powered operation. • Studied dominant charge transport mechanism in the devices. [ABSTRACT FROM AUTHOR]

Highlights • The p-ZnTe/n-CdS heterojunction photodetectors were fabricated. • New technique of nanoparticle incorporation was used to dope ZnTe with bismuth. • The photocurrent increased nearly 10 times after doping. • The spectral response curve became sharper after doping. • The response time of the device became faster after doping. Abstract The effect of bismuth nanoparticle incorporation on the characteristics of p-ZnTe/n-CdS light sensors is evaluated in detail. The device was fabricated by vacuum evaporation method. The bismuth nanoparticles were obtained on the substrates kept at 453 K. The electrical conductivity of ZnTe layer was found to increase significantly after the introduction of bismuth nanoparticles. The I-V and C-V characteristics of the devices showed significant improvement in the electrical characteristics after doping. The photo-response properties of the diodes was also found to improve after the incorporation of bismuth. The photocurrent increased nearly 10 times and the photo-response was found to be much faster. [ABSTRACT FROM AUTHOR]

A highly hydrophobic porphyrin: di-octadecyl-amide deuteroporphyrin (D-ODA) was synthesized and incorporated into liposomes (Lipo-D-ODA) through self-assembling of the aliphatic chains. From the fluorescence spectra, it was concluded that the long alkyl carboxylate chains accommodate the sensitizer into the lipid bilayer, is less exposed to quenching induced by aggregation. The light excited liposome Lipo-D*-ODA activated the ground state molecular oxygen to produce oxygen singlet or superoxide anion. The electrochemical responses of two structurally different redox-active analytes were studied. Quercetin oxidation at 200 mV was only observed after irradiation on the Lipo-D-ODA/Quercetin, indicating that it is embedded in the liposome and requires membrane rupture. On the contrary, the signal of Ferrocene-ODA was independent of irradiation because the redox polar moieties (Ferrocene) were oriented in aqueous space. [ABSTRACT FROM AUTHOR]

There is growing interest in "more-than-human" influences on places and practices. However, while the theoretical thinking in this field is well developed, methodology and methods lag behind. Borrowing insights from feminist geographers' articulation of "response", we explore how participatory photography can be used to examine more-than-human processes through a case study of marginal homemaking in Khulna city in Bangladesh. Our photo-response method focuses on performances of seeing, telling and being together to enhance the co-production of "knowledges". We conclude that analysing three stages of "response" within participatory photography provides new insights for conducting research in, with and as more-than-human worlds. [ABSTRACT FROM AUTHOR]

Copper (Cu) doped p -CdS nanoparticles have been synthesized via sol-gel method. The as-synthesized nanoparticles were successfully characterized and implemented for fabrication of Glass/ITO/ n -ZnO/ p -CdS/Al thin film photodiode. The fabricated device is tested for small (−1 V to +1 V) bias voltage. Results verified that the junction leakage current within the dark is very small. During reverse bias condition, the maximum amount of photocurrent is obtained under illumination of 100 μW/cm 2 . Electrical characterizations confirmed that the external quantum efficiency (EQE), gain and responsivity of n -ZnO/ p -CdS photodiode show improved photo response than conventional p -type materials for such a small bias voltage. It is therefore revealed that the Cu-doped CdS nanoparticles is an efficient p -type material for fabrication of thin film photo-devices. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate a novel approach to use vanadium pentaoxide (V 2 O 5 ) as a single material that can simultaneously function as both electron blocking and transport layers (EBLs and ETLs) in an organic photo-detector (OPD). Composite of V 2 O 5 and PEDOT:PSS was introduced as hole transport layer (HTL) whereas, single V 2 O 5 film was utilised as an ETL. The resultant device had the ITO/PEDOT:PSS+V 2 O 5 /PCDTBT:PC 71 BM/ V 2 O 5 /Al architecture and exhibited a new range of photo-current as well as showed an enhanced photo-response. For comparison, we also fabricated devices with ITO/PCDTBT:PC 71 BM/Al , ITO/PEDOT:PSS/PCDTBT:PC 71 BM/Al and ITO/PEDOT:PSS+V 2 O 5 /PCDTBT:PC 71 BM/Al architectures. The device with ITO/PCDTBT:PC 71 BM/Al architecture showed a photo-response in the range of ∼2.3 (OFF) to ∼6.7 mA/cm 2 (ON) which increased to almost double after the inclusion of PEDOT:PSS as an HTL and reached to ∼2.3 and ∼12.6 mA/cm 2 in OFF and ON states, respectively. In the third variant of devices with the addition of V 2 O 5 in PEDOT:PSS to form a composite HTL, the photo-response narrowed down to ∼5.4 (OFF) and ∼12.6 mA/cm 2 (ON). Lastly, the new approach with the addition of an ultrathin V 2 O 5 layer as an ETL along with composite HTL demonstrated a new range of photo-current with enhanced photo-response in the range of 13.2 mA/cm 2 (OFF) and ∼20.7 mA/cm 2 (ON). The findings of the current work suggest that addition of V 2 O 5 based ETL has tuned both photo-current and response range of the OPDs. In addition, inclusion of V 2 O 5 into the PEDOT:PSS could effectively block the electrons due to its large band-gap. [ABSTRACT FROM AUTHOR]

Photo-induced multi-color fluorescent hydrogels based on CPMC, SPCOOH and DCF for optical information encryption and coding. [Display omitted] • We fabricate multi-color fluorescent hydrogels containing CPMC, SPCOOH and DCF. • Hydrogels prove various photo-response induced by light of different band. • Based on the effect of borax, hydrogels possess reversible cross-linking property. • We apply the hydrogels to optical information coding and encryption. In this study, we proposed a method to prepare multi-color fluorescent hydrogels with polyvinyl alcohol (PVA) as the cross-linking network and 7-(6-carboxylpentoxy)-4-methylcoumarin (CPMC), N-ethoxyhexanoate-3,3-dimethyl-6-nitro-indolinspiropyran (SPCOOH) and 2′,7′-dichlorofluorescein (DCF) were introduced to the system. Due to the hydroxyl group in PVA can form a reversible borate bond with borax, the hydrogel could be combined with each other through this chemical bond, thus hydrogels possess reversible cross-linking property and programmable property. The introduction of CPMC, SPCOOH and DCF into the hydrogel could give the hydrogel different photo-response properties. Under UV light irradiation, PVA-CPMC, PVA-CPMC/DCF, PVA-SPCOOH and PVA/DCF hydrogels could emit blue, cyan, pink purple and green fluorescence respectively. In addition, PVA/DCF and PVA-CPMC/DCF hydrogels could emit green fluorescence under 505 nm light irradiation. Based on the various properties of hydrogels, we respectively demonstrated the application of hydrogels in the fields of two-dimensional information encryption, three-dimensional information encryption, three-dimensional information coding and anti-counterfeiting, which can achieve the expected results. Therefore, multi-color fluorescent hydrogels may have potential applications in information encryption, information coding, flexible display and other fields. [ABSTRACT FROM AUTHOR]

Inorganic-organic nanocomposites are synthesized and applied in polymer solar cells (PSCs) for improving power conversion efficiency (PEC). The hexagonal NaYbF 4 :Tb/Eu nanocrystals are synthesized, and then two organic molecules, phenanthroline (Phen) and thenoyltrifluroacetone (TTA), are introduced to modify the surface of the NaYbF 4 :Tb/Eu. As organic antennas, Phen and TTA can absorb UV and then transfer energy to inorganic nanocrystals. The prepared nanocomposites combine upconversion (UC) and downshift (DS) process under excitation, which can convert them into visible light. Thus, the inorganic-organic nanocomposites display photoresponse both in UV and NIR region. Two organic ligands and Tb 3+ play an indispensable role during the energy transfer process. The enhanced UC and tunable DS emission match well with absorption of active layer of PSC, which can enhance the performance of PSC. The open-circuit voltage (V oc ) and short-circuit current density (J sc ) of the devices are about 0.77 V and 16.48 mA cm −2 , respectively. And the PEC of PSC can be increased 7.85%, which is about 10.2% higher than that of the reference device without UC and DS. [ABSTRACT FROM AUTHOR]

Recently, transition metal chalcogenides were found to be the most promising candidates for photosensor- and photodetector-based applications. This study reports the photodetection and response properties of tin selenide (SnSe) crystals grown by the direct vapour transport (DVT) technique. The basic properties of SnSe have been reported in a previous article. Photodetection properties are investigated using polychromatic or monochromatic light of varying intensities and bias voltages. Results depict that detectors work congenially under monochromatic sources of light. It is observed that responsivity (Rλ) is higher for red, while detectivity and sensitivity are observed to be maximum for blue light under the self-biased (no bias) condition. The results observed under varying intensity (spot size) in the absence of biassing suggest that as intensity rises, all the parameters of the photodetector are also rising, while at constant intensity (30 mW/cm2), by varying the bias voltage, the detectivity of red light is decreasing due to an increment in dark current. Photodetectors are more efficient at converting optical signals to electrical signals, and their sensitivity is colour-dependent. Mainly, it is observed that monochromatic light shows high sensitivity to low bias voltages, while polychromatic light shows high sensitivity to high voltages. Observed results point to the detection of both monochromatic and polychromatic light by the fabricated detector, which can be applied to SnSe-based devices. A device can be used to fabricate colour and intensity detection. [Display omitted] • DVT grown SnSe crystals were prepared for photo detection study. • The fabricated photodetector can be used as a multicolor's photodetector in the visible range of light. • It could be used to make next-generation self-driven photo-switching diodes. • This versatile behaviour of detector can be helpful to design colour (wavelength) sensors. [ABSTRACT FROM AUTHOR]

Dibutyl phthalate (DBP), as a plasticizer, has been widely used in the manufacture of plastic products. However, it is generally acknowledged that DBP is an endocrine disruptor, which would cause harm to both humans and wildlife. Generally, trace DBP in river water, soil or food is hard to be detected accurately. To solve this case, a core-shell hollow structured molecularly imprinting polymer, PH-MIPs, was synthesised via surface imprinting technology. It is noteworthy that the prepared PH-MIPs can specifically absorb and release DBP irradiated by different wavelengths of light. More importantly, the absorption capacity of PH-MIPs reaches up to 5.2 mg·g−1 without obvious attenuation in absorption performance after 4 loops of photo-controlled uptake and release of DBP. Furthermore, the PH-MIPs exhibit excellent selective absorption properties, supported by an imprinting factor of 3.4. Finally, the prepared PH-MIPs were applied to enrich and extract DBP in river water samples with the recovery rate of 83.2%. In general, the proposed PH-MIPs exhibit excellent practicability, which offers a method for the content determination of DBP as a high-efficiency solid-phase extractant for the enrichment and extraction of target pollutants. [Display omitted] • A functional photoresponsive monomer, MAPASA, was synthesised, the conformation of which can change under the light of 365 nm and 440 nm (or darkness). • Hollow-structured PH-MIPs synthesised on the surface of SiO 2 carriers with MAPASA provide assurance of photoresponsive selectivity adsorption and release of dibutyl phthalate (DBP). • To establish a photo-controllable extraction and enrichment method for determining the content of DBP. [ABSTRACT FROM AUTHOR]

Photo-responsive polymers, obtained by incorporation of photochromic azobenzene groups into polymer, can display reversible photoactuation behavior. However, the damage can cause a reduction in their service scope or service lifetime. It remains a challenge to design healable and reprocessable azobenzene-containing polymers. The polyaddition of isophorone diisocyanate (IPDI) with p -diaminoazobenzene (DAAB) and amino-terminated poly(propylene glycol) (D2000) was performed to prepare the main-chain polyurea elastomer. The hydrogen bonding between urea groups can enhance self-healing of polyurea elastomer, but its influence on photo-responsive behavior of polyurea elastomer is not clear. The proportion of ordered hydrogen bonds was regulated by changing azobenzene content and the ratio of hard/soft segments. The ordered hydrogen bonds played a fundamental role in the maximum peak intensity of polyurea, while they had no direct effect on the photo-responsive efficiency of polyurea. This study provides a feasible way to obtain healable and reprocessable azobenzene-containing polymers. • The proportion of ordered hydrogen bonds was regulated by changing azobenzene content or the ratio of hard/soft segments. • The ordered hydrogen bonds played a fundamental role in the maximum peak intensity of polyurea. • The ordered hydrogen bonds had no direct effect on the photo-responsive efficiency of polyurea. • The azobenzene-containing polyurea films possessed healable and reprocessable ability. [ABSTRACT FROM AUTHOR]

• Development of a novel CD with light-responsive oxidase-like activity. • The CD exhibits a desirable affinity to chromogenic substrate with a Km of 0.22 mM. • The determination of TOC in fruits was realized by coupling CD with chromogenic substrate. Evaluation of total antioxidant capacity (TAC) in fruits is essential for dietary guidance and health monitoring. Here, we have exploited light-response carbon dots (CDs) as oxidase-like nanozyme to determine the TAC of fruits. The CDs possess excellent oxidase-like activity with light stimulation due to the accelerated intramolecular charge transfer caused by abundant electron donating/drawing groups in precursors. The scavenger experiment reveals that the catalytic intermediate could be hydroxyl radical, which can oxidize the colorimetric substrate. With the introduction of antioxidants, the oxidization of colorimetric substrate will be alleviated due to the scavenging of this intermediate by antioxidants. Based on this, we have successfully detected three antioxidants and obtained TAC of fruits with desirable results. This work affords a rapid, cost-effective and convenient analysis tool for TAC, as well as building a strong bridge between CDs and the development of photo-responsive oxidase-like nanozymes. [ABSTRACT FROM AUTHOR]

An anatase TiO2 film sensor was prepared by a facile in-situ method on the interdigitated Au electrode deposited on the alumina substrate. The structure, morphology and the optical properties of the in-situ TiO2 film sensor were characterized by X-ray diffraction, Scanning Electron Microscopy, and UV-vis diffuse reflectance spectra. The photo-assisted gas sensitivities of the prepared film towards H2 gas were evaluated at room temperature in N2 and synthetic air atmospheres. As compared to TiO2 film sensor prepared by drop-coating method, this in-situ TiO2 film sensor exhibited a more compact structure composed of uniform TiO2 microspheres as well as a better gas sensitivity towards H2 under UV irradiation, especially in synthetic air. The photo-electrochemical measurements suggest that these improvements may be associated with the efficient charge transfer in the TiO2 interface induced by the TiO2 microsphere structure. This study might offer a feasible approach to develop photo-assisted gas sensors at ambient temperature. [ABSTRACT FROM AUTHOR]

Ordered CdO nanowire branched arrays were designed and synthesized within a single hierarchical nanostructures. Such novel ordered nanowire branched arrays (ONBAs) were fabricated via one-step heating (OSH) gas-phase process and achieved the most uniform CdO nanowire branched arrays ever reported. By varying the mass ratio of CdO and Bi and adjusting the deposition position, the diameters and densities of the nanowires can be precisely controlled. A photodetector composed of CdO ONBAs demonstrated a drastic increase 867% in electrical current. In contrast, the device with a CdO thin film shows only 289% increase in current. These indicate that the CdO ONBAs are promising for photodetector applications. [ABSTRACT FROM AUTHOR]

Solid-state dye-sensitized solar cells (ssDSSC) constitute a major approach to photovoltaic energy conversion with efficiencies over 8% reported thanks to the rational design of efficient porous metal oxide electrodes, organic chromophores, and hole transporters. Among the various strategies used to push the performance ahead, doping of the nanocrystalline titanium dioxide (TiO2) electrode is regularly proposed to extend the photo-activity of the materials into the visible range. However, although various beneficial effects for device performance have been observed in the literature, they remain strongly dependent on the method used for the production of the metal oxide, and the influence of nitrogen atoms on charge kinetics remains unclear. To shed light on this open question, we synthesized a set of N-doped TiO2 nanopowders with various nitrogen contents, and exploited them for the fabrication of ssDSSC. Particularly, we carefully analyzed the localization of the dopants using X-ray photo-electron spectroscopy (XPS) and monitored their influence on the photo-induced charge kinetics probed both at the material and device levels. We demonstrate a strong correlation between the kinetics of photo-induced charge carriers probed both at the level of the nanopowders and at the level of working solar cells, illustrating a direct transposition of the photo-physic properties from materials to devices. [ABSTRACT FROM AUTHOR]

Transition metal chalcogenides (TMCs) have been extensively investigated due to their pervasive range of properties for the fabrication of several next-generation optoelectronic devices including flexible detectors, photodetectors, and photo sensors. This article reports the growth, characterization, and photodetection and response study of crystalline tin selenide (SnSe) grown by the direct vapor transport (DVT) technique. The stoichiometric confirmation of as-grown compound tin mono-selenide (SnSe) was confirmed by EDAX spectra. Structural confirmation was carried out using powder X-Ray Diffraction (PXRD). The bandgap of the grown crystals was also calculated from Tauc's plot. Anisotropic photodetection study of the SnSe photodetector demonstrates the superior photocurrent of 0.62 μA under polychromatic light for the I-II configurations of contacts. The stability of isotropic configuration is also observed to be high compared to anisotropic configuration. The results suggest isotropic contact configuration is most preferable for the SnSe photodetector. We observed that, under zero biasing conditions, the device performance improves, which indicates that the fabricated photo-diode exhibits an adequate photosensitive nature. It is observed that the device performs wisely under the self-driven condition, which points out the adequate photo-conductive (photo-self-driven) nature of the detector. [Display omitted] • As grown crystals were characterized by different techniques such as EDAX and EDAX mapping, XRD, Optical microscopy, SEM and UV-Vis. • SnSe based photodetector shows the photocurrent and responsivity of 0.62 μA and 3.01 mA/W in anisotropy (perpendicular to c-axis) configuration. • The obtain photocurrent is superior in anisotropy (perpendicular to c-axis) configuration then (parallel to c-axis) isotropy. • This work demonstrates the potential of SnSe crystal in the field of photonics as an anisotropic optoelectronic sensor. • It could be used to make next-generation self-driven photo-switching diodes, as conclusively demonstrated by the enhanced device performance shown in this paper. [ABSTRACT FROM AUTHOR]

Much enhanced photo-absorption of Bi 2 MoO 6 was realized by introduction of an organic dye sensitizer, copper phthalocyanine (CuPc). The CuPc/Bi 2 MoO 6 composite photocatalyst showed photo-response in the whole visible spectrum and even the near infrared region. As a result, it exhibited much higher photocatalytic activity than bare Bi 2 MoO 6 in photo-degradation of RhB and phenol under simulated solar light. Moreover, the sensitization effect of CuPc was testified by photo-degradation of RhB under a red LED (? = 620 nm)irradiation. [ABSTRACT FROM AUTHOR]

We investigated the feasibility of obtaining large photoresponse in metal-semiconductor-metal (MSM) type single nanowire device where one contact can be blocking type. We showed that suitable modification of the blocking contact by deposition of a capping metal using focused electron beam (FEB) can lead to considerable enhancement of the photoresponse. The work was done in a single Cu:TCNQ nanowire device fabricated by direct growth of nanowires (NW) from pre-patterned Cu electrode which makes the contact ohmic with the other contact made from Au. Analysis of the data shows that the large photoresponse of the devices arises predominantly due to reduction of the barriers at the Au/NW blocking contact on illumination. This is caused by the diffusion of the photo generated carriers from the nanowires to the contact region. When the barrier height is further reduced by treating the contact with FEB deposited Pt, this results in a large enhancement in the device photoresponse. [ABSTRACT FROM AUTHOR]

Abstract: It is reported here that the microrod array of CdSe on indium doped tin oxide coated conducting glass (ITO) substrate has been developed by a simple electrochemical synthesis method. The electrodeposition of CdSe was also investigated by cyclic voltammetric technique. The sample was characterized by XRD, EDX, FESEM and UV–vis spectroscopic. The X-ray diffraction investigation demonstrates that the CdSe microrod is a uniform hexagonal CdSe crystal. EDX shows that the high purity CdSe is obtained. Field emission scanning electron microscope (FESEM) results show that the microrods’ length, diameter, and direction of growth are nearly uniform and perpendicular to the ITO substrate. UV–vis absorption spectrum study shows the presence of direct transition with the band gap energy 2.13eV. Photoelectrochemical solar cells are constructed using CdSe microrod array as the photocathode in polysulphide electrolyte and their power output characteristics are studied. [Copyright &y& Elsevier]

Abstract: Ni/In x Ga1 −x N/GaN Schottky barrier solar cells with different In contents (x =0.07/0.13) and two types of Schottky patterns (semitransparent current spreading layer and grid contact) are fabricated and the dependences of photovoltaic performances of these solar cells on In contents and Schottky patterns are studied. Solar cells with semitransparent contact have almost the same open-circuit voltages (V oc) as solar cells with grid contact and exhibit a higher fill factor (FF). However, solar cells with grid contact exhibit a higher maximum output power density (P max) than semitransparent contact due to their larger short-circuit current density (J sc). On the other hand, V oc and FF decrease significantly with increasing In content (beyond the decrease expected from the band gap of InGaN). By comparing the X-ray rocking curves, AFM images, dark current characteristics and spectral responsivities, it could be concluded that the deterioration of InGaN crystal quality with increasing In content is the dominant reason accounting for the strong decrease of V oc and FF. In addition, using AMPS simulation, the band structure and ideal spectral responsivities are obtained. Comparison of the experimental and simulated results also shows that high crystal quality is a key factor to obtain high performance InGaN-based Schottky barrier photovoltaic cells. [Copyright &y& Elsevier]

Abstract: We have investigated the photo-response characteristics of organic photosensors (OPS) integrated with pentacene based thin film transistors (TFTs). The fabricated device configuration is PEN/ITO/PEDOT:PSS/(poly(3-hexylethiophene)/phenyl-C61-butryic acid methyl ester) (P3HT/PCBM)/Al and PDMS/Au/(poly-4-vinyphenol) (PVP)/pentacene/Au. In order to study the effect of the applied voltage to the pentacene-TFT on the OPS, each device is connected in series. The response current is tuned dependant on the gate-source voltage and the anode-source voltage. The change of the photo induced ON current in the integrated device is measured under light illuminations ranging from 50mW/cm2 to 500mW/cm2; the corresponding photo-response (ΔI/I 0) of the devices varied from 0.16 to 1.9. We found that the photo-response characteristic is high at the low anode-source voltage and high gate-source voltage. [Copyright &y& Elsevier]