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In this article, the beneficial effect of surface passivation rendered by the amalgamation of co-ordinating tri-n-octylphophine (TOP), oleylamine (OLA), and oleic acid mixture on the structural and optoelectronic properties of lead selenide (PbSe) quantum dots (QDs) (~6–20 nm) and its respective poly(3-hexylthiophene) (P3HT) polymer: PbSe composites has been demonstrated. Here, OLA ligand is found to play a major role in the nucleation and growth mechanism and hence control of the size distribution of the resultant PbSe QDs. The superior quality of the OLA-passivated PbSe QDs can be attributed to its better homogeneity, colloidal and photostability, which it imparts to its respective polymer: PbSe composites as compared to the corresponding OA-passivated PbSe QDs. The role of post-synthesis ligand exchange/removal has been envisaged to facilitate efficient charge transport in hybrid composites and has been modeled pictorially. Accordingly, P3HT: PbSe (OLA) composites exhibit significant PL quenching and hence higher current and better charge transfer characteristics as compared to their OA-counterparts. An exhaustive structural, optical and electrical investigations as corroborated by various complimentary techniques (TEM/SEM, XRD, NMR, FTIR, NIR-Absorption, PL, XPS, and I-V) have resulted in some significant findings wherein the effective stabilizing and etching properties with an optimum binding capability of OLA ligands to PbSe surface are found to be imperative for its effective utilization in hybrid composite photovoltaic devices. The superior morphology, optical properties, and higher stability of OLA-capped PbSe QDs can aid in the proper understanding of efficient charge separation and transport in hybrid organic–inorganic nanocomposites solar cells based on colloidal PbSe nanocrystals.

We report the fabrication and characterization of varying concentration (x) of copper (Cu)-doped TiO2 nanocomposites [Cu( x )TiO2(1- x )] exploring the photocatalytic properties for sunscreen appli...

A new self-activated green-yellow emitting Gd2CaZnO5 (GCZO) phosphor was synthesized using solid-state reaction method at high-temperature. XRD analysis confirmed the orthorhombic structure of the sample with the Pbnm space group. SEM micrographs reveal the irregular morphology with micron sized particles. Detailed photoluminescence (PL) analysis revealed that the excitation of the phosphor lies in the UV range (˜377 nm) with the related broad green-yellow emission centered at 530 nm. The broad band emission ranging from ˜450 nm to 650 nm can be attributed to the surface defects and oxygen vacancies. The calculated luminescence decay lifetime for the optimized phosphor was found to be 2.925 μs. Furthermore, the color-coordinate (x, y) were calculated and found to be (0.44, 0.45), which lies in the green-yellow (˜540 nm) region of the electromagnetic spectrum. The values of color coordinates and Color correlated temperature of 3289 K support the synthesized phosphor for the emission of warm white-light. These results perfectly established the suitability of this green-yellow emitting GCZO phosphor for Ultra-Violet Light-Emitting Diodes (LEDs) excited white-LED applications.

The Mn, Al co-doped ZnO samples were synthesized using solid-state reaction method and were annealed in furnace at 300 °C, 600 °C and 900°C temperature. All the samples prepared were investigated in detail for analysis of their structural, morphological, optical, magnetic and electrical behavior. The XRD data confirmed the hexagonal wurtzite structure of pristine, Mn doped and Al, Mn co-doped ZnO. For morphological investigation SEM and TEM techniques were employed. The PL properties of the ZnO:Mn, Al sample revealed emission in the blue region (415–438 nm). Furthermore, IV studies were carried out to examine the conductivity of the ZnO:Mn, Al samples and maximum conductivity was found in the sample with 5% Al doping and annealing temperature 600 °C. The magnetic measurements revealed room temperature ferromagnetic behavior in the optimized ZnO:Mn, Al sample annealed at 600 °C which indicates its suitability for Magneto-Opto Electronic Applications.

Dye-sensitized solar cells (DSSCs) have become the subject matter of significant interest for the research and due to their urge in the field of energy conservation. The safe supply of energy is welfare of human life. However, as an unattainable power-energy conservation source, also depletion of fossil fuels is an unfortunate mandate and, definitely it is imminent. To encounter this critical issue of energy, non-conventional sources of energy have gained lots of attention, especially solar energy because it’s a device that converts light-energy directly to electrical-energy without harming the environment. DSSCs provides a reliable and a cheap alternative for different kinds of Photovoltaics. The spectacle realization of Dye-sensitized-solar-cell is typically relying on photosensitizer (Dye), electrolyte and metal oxide semiconductor. A natural dye has become most credible alternative for such expensive and rare inorganic/chemical sensitizers, due to its lower cost, easy fabrication, eco-friendly and abundance of raw material. Also, DSSC has easily implemented technology with significant efficiency. This review paper enlightens the emergence, operation/fabrication, components and development of DSSCs using natural photo-sensitizers and factors that affect the stability.

Photoactive degradation of textile malachite green (MG), methylene blue (MB) dyes has been permeated on metal oxide TiO2 nanoparticles under sunlight. Semiconductor photocatalysis is a promising method for removal of toxic chemicals from wastewater produced by industry. Due to tunable bandgap, TiO2 among various semiconductor studied mostly. Large band gap (UV active) and recombination of exciton in TiO2 less active in photo degradation. Noble metals such as gold nanoparticles deposited on TiO2 surface increased the optical activity and to shift optical response to visible region. Degradation detail has been carried out by characterisation such as XRD, UV-Vis, PL, TEM, and SEM for MG and MB textile dyes under sunlight irradiation. UV-visible absorption spectra and PL spectra shows that photo-response of as prepared sample is extended from UV to visible region. PL intensity decreases with increases in concentration of Au nanoparticles, decreases in intensity in optical spectra of Au–TiO2 composites shows that charge transfer process dominates. Au–TiO2 plays an essential role in enhancing photocatalytical activity. Decolorization optimization depends on catalyst concentration, Dye concentration, light intensity and, irradiation time.

Costunolides, an important sesquiterpene lactone (STL) isolated from Saussurea lappa, are the major pharmaceutical ingredient of various drug formulations. Identification of the genes and transcriptional regulation of costunolide biosynthesis pathway in S. lappa will propose alternatives for engineering enhanced metabolite biosynthesis in plant. Here, we aimed to unravel the transcription factors (TFs) regulating the costunolide biosynthesis. Comparative transcriptome analysis of root and leaf tissues and transcripts were annotated using various in silico tools. Putative transcription factors were identified using PlantTFDB and TF- gene co-expression network was generated followed by clustering using module based analysis to observe their coordinated behaviour. The module 1 was found to be significant based on its enrichment with major pathway genes. Further, promoter cloning determined the cis acting elements in costunolide synthase (SlCOS1) gene which catalyses the final key step of costunolide biosynthesis. Bioinformatics tools were employed to predict the cis regulatory elements, leading to the identification of MYB family of TFs as an interacting partner of SlCOS1 gene. The present study is the pioneer attempt for TF prediction and elucidation of their regulatory role in costunolide synthesis. This will help in future metabolic engineering of the pharmaceutically important STLs and their yield improvement.

Silver oxide nanoparticles (Ag2O NPs) are used widely in fuel cells, sensor, antimicrobial activity, analgesics, catalysis, optics, cosmetic and drug delivery. These nanoparticles are synthesized by chemical, physical and green route. In the present study, the (Ag2O NPs) are synthesized by green route as it is environment friendly, less hazardous, inexpensive and also plants used as capping agent have phytochemicals which act as stabilizing agent and reducing agent. Artocarpus Hetrophyllus plant extract is used for the synthesis of Ag2O NPs by natural chemicals. The leaves were washed several times and then grinded in pestle mortar and finally filtered by Whatman filter paper for further reaction with Silver nitrate (AgNO3 salt) as precursor. The reaction mixture is then heated and stirred at 60–80 °C for 60 mins. The temperature, pH and time period of the reaction mixture is very crucial for the formation of Ag2O NPs. The XRD (X-ray diffraction) technique shows the presence of Ag2O NPs crystallized in Face-centered cubic structure which are in well agreement with the JCPDS Card No.004-0783. UV–Vis spectra as recorded in the 200–700 nm wavelength range shows the band absorbance at 517 nm and band gap of Ag2O NPs is 2.1 eV as determined by Tauc’s plot. The FTIR (Fourier transform infrared spectroscopy) spectra shows the presence of functional group absorbance peaks at 3468 cm−1, 2842 cm−1, 1637 cm−1, 1586 cm−1, 1407 cm−1, 1355 cm−1, 766 cm−1 corresponding to OH, CH2, COOH, C C, C C, C H, Ag O groups respectively present in phytochemicals. DLS (Dynamic light scattering) reveals the Hydrodynamic diameter as 212 nm and monodispersity (Polydispersity index

Magnetic impurity in wide bandgap semiconductors incorporate magneto-electro-optical properties. For the vast application and demand of future market devices; Fe-doped ZnO (Fe-ZnO) powders at different Fe doping concentrations were synthesized by solid-state reaction route. 3%Fe-doped ZnO thin films were also grown using solution route as a powder sample of 3%Fe-ZnO was found to be the Room Temperature Ferromagnetic (RTFM). X-ray Diffraction (XRD) patterns showed the increase in secondary phases from single phase wurtzite ZnO structure with increase in Fe concentration. UV-Vis absorption spectroscopy (UV-Vis) showed decrease in bandgap. In Photoluminescence (PL) spectra quenching is observed as Fe3+ ions occupies the photogenerated Zn ion with an increase in doping concentration. SEM analysis revealed the spherical morphology of nanoparticles ranges in 50 nm. Agglomerations of the Fe2+/Fe3+ ions leads to paramagnetism with an increase in Fe doping. Vibrating Sample Magnetometer (VSM) showed that only 3%Fe-ZnO sample was found to be RTFM whereas paramagnetic behavior dominates with the increase in Fe doping concentration. Since, the type of synthesis route adopted doesn’t have a control of physical and chemical property of any material; Rather the choice of dopant (magnetic-Fe) and the host (optical-ZnO) in an optimized ratio can proves to be a single material with magnetic-optical properties. This material as combination of two properties proves to be a potential for spintronic and biosensor-based device applications both in non-medical and medical areas.

Synthesis of titanium dioxide nanoparticles (TiO2 NPs) has been done by sol-gel-hydrothermal colloidal route in two different apparatus; one being simple stainless steel (named as TiO2-B) and other...

Quaternary chalcopyrite, i.e., Cu2ZnSnS4 (CZTS) nanoparticles films have been proposed as a novel matrix system for enzyme-based electrochemical biosensors providing a non-toxic, low-cost alternative for the fabrication of bioelectrodes. The easy tuneability of the band gap of CZTS by varying the cation ratio and size of nanoparticles facilitate to impart desirable electrical properties in the material. Butylamine capped spherical CZTS nanoparticles of size 15–16 nm and band gap 2.65 eV have been synthesized by colloidal hot injection technique. The films of CZTS onto ITO substrates are deposited using dip coating technique, and uricase enzyme have been immobilized onto CZTS films using EDC-NHS binding chemistry. Electrochemical analyses of this bioelectrode revealed that the uricase/CZTS/ITO/glass electrode exhibits good linearity over a wide range of 0–700 μM uric acid concentration with a limit of detection (LOD) of 0.066 µM. The low value of 0.13 × 10−4 M of Michaelis–Menten constant (Km) indicate the enhanced affinity of immobilized enzyme (uricase) towards uric acid. Thus, the present report confirms the promising application of the p-type CZTS thin film matrix for the realization of an electrochemical biosensor.

In this paper, pure and Fe2O3 (1–5 mol %) doped Cr2O3has been synthesized using a solid-state synthesis method. X-ray diffraction pattern of pure and Fe2O3: Cr2O3 has a similar crystallographic hexagonal phase with space group R-3c and lattice parameter, a = 5.002 A; c = 13.620 A and, a = 4.913 A; c = 13.469 A, respectively; average crystallite size being ∼29.46 nm. Fe3+ incorporation in Cr2O3 lattice leads to the increase in the particle size as Fe3+has larger ionic radii (∼0.67 A) than Cr3+ (∼0.64 A).Both XRD and EDX showed that Fe2O3: Cr2O3 nanoparticles exhibit no impurities phases, confirms the presence of Cr, Fe, and O materials. The Tauc’s plot showed a decrease in optical band gap from 3.10 to 2.95 eV for Fe content of 0 to 5 mol%, respectively. All samples revealed weak ferromagnetic behavior at room temperature. SEM analysis revealed an increase in particle size from16-38 nm. Electrically, at low frequencies, undoped and low concentration of Fe in Fe2O3: Cr2O3 shows high values of dielectric constant. Further, this value decreases continuously with the increase in frequency. The study revealed that 3% Fe2O3: Cr2O3 sample is excellent among all the doping concentrations (1–5 mol%) for magneto-optoelectronic device applications.

This work reports the synthesis of varied shaped Cu2ZnSnS4 (CZTS) nano inks in a most stable kesterite phase via a hot injection colloidal route. CZTS nanoparticles of varied shape were synthesized by using various capping ligands with the introduction of butylamine as a new capping ligand and two different sulfur precursors respectively. The shape of the as-synthesized kesterite CZTS nanocrystals can be well controlled in the form of nanofibers, spherical nanoparticles, nano hexagons, nanotriangles, and nanodiscs. A detailed analysis of the effects of various capping ligand and sulfur source on reaction conditions to obtain pure phase kesterite CZTS nanocrystals for different shapes is explained using LaMer's diagram. It has been found that the choice of sulfur precursor also plays an important role in determining the symmetry and orientation of the plane of the CZTS nanocrystals. Due to different morphology and capping ligands present on the surface, diverse surface properties were obtained which was confirmed by contact angle measurements. The variation in the band gap was also found with changes in morphology of kesterite phased CZTS nanoparticles. Due to variations obtained in band gap, changes in I-V characteristics were also observed which may leads different CZTS nanoparticles to have their potential applications in different regime other than photovoltaics like sensors, photocatalysis etc.

In indium phosphide quantum dots (InP QDs), the presence of surface states due to unbonded indium or phosphorus atoms quenches its photoluminescence (PL) efficiencies. Hence, it is imperative to passivate these surface states to achieve high photoluminescence efficiencies of InP nanocrystals. In this work, a novel post-synthesis nascent H chemical treatment to enhance the quantum yield of single-pot, wet chemical route synthesized InP QD's is reported for the first time. The main advantages of this post-synthesis treatment are: (i) it is easy, inexpensive and reproducible and (ii) it does not involve harsh chemical treatment viz. dipping of InP QDs in HF-based solutions, nor it requires annealing at high temperatures which may be detrimental to the fragile structure of InP. The significant increment in PL intensity upon aforementioned hydrogen treatment is due to the passivation of surface states and structural recrystallization mechanism that promotes radiative recombination of electrons and holes and hence higher lifetime values. An enhancement in PL intensity of as-synthesized InP QDs upon nascent hydrogen treatment is quite remarkable and is even better than that accomplished by InP-ZnS core-shell QDs with similar size-distribution. The hydrophobicity of H-treated InP QD's is found to be more than untreated InP thus implying higher compactness and structural rigidity similar to as achieved by InP-ZnS core-shell QDs. Mechanisms related to nascent hydrogen treatment, photo-oxidation and PL enhancement and its effect on the surface stoichiometry of InP QDs are discussed via structural, morphological, compositional and optical studies corroborated by various complementary techniques viz. SEM, HRTEM, EDAX,NMR, DLS, Zeta Potential, Contact Angle, PL and Transient Absorption respectively. The application of InP films as a humidity sensor has been demonstrated and untreated InP film in particular shows higher sensitivity values upon exposure to humid treatment as compared with H-treated InP and InP-ZnS core-shell QD's respectively.

In this work, stable Cu2ZnSnS4 (CZTS) nanocrystals (NCs) in pure kesterite phase were synthesized by a facile one-pot rapid injection technique (colloidal route). Time-dependent reaction mechanism for the synthesis of CZTS nanoparticles is explained. When TOP-S (Tri-octyl phosphine–sulphur) was injected in the CuZnSn-complex with TOPO (Tri-octyl phosphine oxide) as capping ligand, orthorhombic phase Cu2−XS nanoparticles of spherical shape were found at nucleation sites. With an advancement in the reaction time, Sn got infused in Cu2−XS to form Cu2SnS3 and its shape got deformed. Further increase in reaction time infuses Zn to form Cu2ZnSnS4 with the gradual vanishing of Cu2−XS and Cu2SnS3 phases and finally, the rod-shaped CZTS Np’s were obtained. This factor of reaction time, which influence the morphology and size were studied in detail. The structural and optical properties of the pure kesterite phase CZTS nanorods were also analysed. The band gap of the rod-like CZTS is determined to be around 1.43 eV, which is an optimum value for solar photoelectric conversion.

A quintessential perspective for elaborating the pivotal role of quinary chalogenides such as CZTSSe plunges the thrust for exploration of non-vacuum approach for development of multicomponent chalcogenides utilizing organic surfactants and solvents for the nanocrystals ideal for photovoltaic applications. The piece of study envisages employment of TOPO-TOP as capping agents-cum-solvents for the very first time and have not been reported for CZTSSe-based materials till date. The work has been forwarded with the variation of anionic ratios in pristine counterparts of CZTSSe; i.e. CZTSe and CZTS in order to envision the potential of quinary chalcogenides wherein properties of two different materials coalesce to impart improved characteristics in CZTSSe. Varying Se:S ratios gradually during nanocrystals' synthesis by high-temperature colloidal route ensued precise control over the phase formation and morphology. With the employment of these capping agents, as-synthesized nanocrystals' are inherently Se-rich and high crystallinity restrains the need for selenization and high temperature annnealing respectively.

For colloidally stable nanoparticle dispersions, it is imperative that some sort of interparticle repulsion is introduced to balance or overcome the ever-present van der Waals forces of attraction. In the present work, we have demonstrated that an efficient stabilization of a TiO2 nanoparticle dispersion depends upon the pH and zeta potential which are influenced by the route of synthesis (aqueous or ethanol based) and by the addition of suitable polymeric dispersants. In this work, both pH and zeta potential of the TiO2 nanoparticles have been accredited as a good index of the magnitude of the interaction between colloidal particles and their measurements are used to assess the stability of TiO2 and polymer/TiO2 composite colloidal systems synthesized via different routes. The concept of steric and electrostatic stabilization of colloids for both TiO2 (aqueous) and TiO2 (ethanol) systems and its corresponding polymer nanocomposites has been explained appropriately by means of a pictorial model. The efficient charge transfer across the polymer-TiO2(aqueous) interface as inferred from photoluminescence quenching measurements meets the desired criteria for the selection of TiO2(aqueous) materials for hybrid organic photovoltaic devices.

In this work, the effect of surface passivation of InP quantum dots (QDs) synthesized by the unconventional tri-n-octyl phosphine (TOP) route, on the structural and optoelectronic properties of their respective polymer nanocomposites, has been demonstrated by dispersing untreated and nascent hydrogen-treated InP QDs in P3HT polymer matrix, respectively. The surface passivation of InP QDs imparts photostability to its corresponding polymer–InP composite as a consequence of a better hydrogen passivation of defects acting as non-radiative recombination centres and can be achieved by employing a simple post-synthesis chemical treatment which is fast, reliable and reproducible. Here, with the distinctive usage of TOP both as a capping ligand and a source of phosphorus in conjunction with a novel chemical treatment, the quantum yield of InP QDs can be significantly enhanced and promotes charge transfer across donor (polymer)–acceptor (InP QDs) interface as supported by photoluminescence (PL) quenching studies as well. The increment in PL intensity upon incorporation of untreated InP QDs into the P3HT polymer matrix can be attributed to the dominance of Forster energy transfer between host P3HT polymer (donor) and guest InP nanocrystals (acceptors) in polymer/InP (untreated) composites. The mechanisms of energy and charge transfer in polymer–InP (u/t) based composites is depicted pictorally. The importance of these two different processes observed in polymer/InP (untreated) and polymer/InP (treated) composites is that it makes them useful for organic optoelectronic, i.e. electroluminescent and photovoltaic devices, respectively.

In this work, charge/energy transfer characteristics of PEDOT:PSS-TiO2 composites have been studied as a function of crystallite sizes of TiO2 nanocrystals annealed at different temperatures for its application in organic optoelectronic devices. From this we found that as the temperature increases energy transfer phenomenon dominates over charge transfer process. We raised the temperature from 200 to 400 °C. Charge transfer process observed at 200 °C and energy transfer process dominated at 400 °C.

In this work, ternary CuInSe 2 (CISe) chalcopyrite nanocrystallites efficiently passivated by a novel combination of capping agents viz: aniline and 1-octadecene during chemical route synthesis were dispersed in conducting polymer matrix poly(3-hexylthiophene) (P3HT). By varying the composition and concentration of the ligands, the properties of the resulting CISe nanocrystallites and its corresponding polymer nanocomposites thus could be tailored. The structural, morphological and optical studies accomplished by various complimentary techniques viz. Transmission Electron Microscopy (TEM), Contact angle, Photoluminescence (PL) and Raman have enabled us to compare the different hybrid organic (polymer)-inorganic nanocomposites. On the basis of aniline–octadecene equilibrium phase diagram, the polydispersity of the CISe nanocrystals could be tuned by using controlled variations in the reaction conditions of nucleation and growth such as composition of the solvent and temperature. To the best of author’s knowledge, the beneficial effects of both the capping agents; aniline and octadecene contributing well in tandem in the development of large-sized (100–125 nm) high quality, sterically- and photo-oxidative stable polycrystalline CISe and its corresponding polymer (P3HT):CISe composites with enhanced charge transfer efficiency has been reported for the first time. The low-cost synthesis and ease of preparation renders this method of great potential for its possible application in low-cost hybrid organic–inorganic photovoltaics.

In present study, we have explained the detailed synthesis chemistry of perovskite material SrTiO3 and the role of annealing temperature on its phase transition, which has not been reported till date. Rare-earth ion Eu was explored as a dopant and its concentration was optimized for achieving maximum luminescence. At annealing temperature of 600 °C, mixed phase consisting of TiO2, SrCO3 and Eu2O3 was observed in the XRD pattern, which eventually vanished at 1000 °C and a pure phase of SrTiO3 was obtained. Besides this, the SrTiO3 undoped and Eu doped samples were synthesized in bulk as well as nano forms, to study their structural, morphological and optical behavior. The SrTiO3:Eu optimized sample annealed at 1000 °C exhibited maximum luminescence due to improved crystallinity and phase purity of the host lattice. The synthesized perovskite sample can have multidisciplinary applications in advanced areas of photovoltaics.

In this study, europium (Eu) and dysprosium-(Dy) doped phosphors, i.e., ZnO:Eu, ZnO:Dy, and Eu:Dy co-doped zinc oxide (ZnO:Eu, Dy) semiconductor phosphors, with optimized concentrations, were synthesized using the conventional solid-state reaction method in an oxygen environment. Detailed structural, morphological, and compositional investigations were conducted using X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray measurements, respectively. Photoluminescence (PL) emission spectra were recorded under different excitation wavelengths to assess the optical characteristics. Electrical analysis was conducted using an inductance (L), capacitance (C), and resistance (R) (LCR) meter and a Keithley source meter, and magnetic analysis was performed using a vibrating sample magnetometer (VSM). XRD confirmed the presence of Eu and Dy ions because the diffraction peaks matched perfectly with those for Eu2O3 and Dy2O3, respectively. The PL results indicated the broad emissions from the samples in the visible region (400–700 nm) under different ultraviolet excitation wavelengths. The VSM results demonstrated that both the Dy-doped and Eu:Dy co-doped ZnO samples exhibited paramagnetic behavior at room temperature, but not the undoped and Eu-doped ZnO samples. The ZnO:Dy sample had superior parameters in terms of the electrical measurements such as the AC/DC conductivity, capacitance, current density, and dielectric constant compared with the ZnO:Eu and ZnO:Eu, Dy samples. These detailed investigations of the optical, magnetic, and electrical properties demonstrate that ZnO:Dy and ZnO:Eu, Dy may be promising materials for use in optical devices.

ZnO being most avid semiconductor metal oxide with a wide band gap of 3.37 eV. ZnO nanostructures were synthesized in the shape of nano rods and flowers to finds their proficiency in the field of photocatalysis and photovoltaics. ZnO nanostructures were investigated in the shape of nano rods and flowers by, X Ray Diffractometer (XRD) confirms pure hexagonal wurtzite structure of ZnO, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) images showed high crystalline morphology and the formation of nano rods and flowers. Ultraviolet and Photoluminescence (PL) study confirms the absorption at 375, 371 nm for ZnO rods and flower which leads to an increase in the band gap and the peak observed at the violet, blue and green emission. The peaks shift is due to increase in defect in flower nanostructures of ZnO, Dynamic Light Scattering (DLS) calculated the average particles size 617 and 823 nm for rods and flower respectively. Conductivity analysis prove that nano flowers are more conductive having more defects and large number of photocatalytic active sites and large number of electron-hole pairs make best suited for photocatalytic specie. Thus, ZnO nano flowers were observed ideal for photocatalysis and photovoltaic applications due its large number of active sites and defects.

Green emitting Ba2SiO4:Tb3+ crystalline semiconducting powders have been synthesized using modified solid-state reaction technique.Synthesized Ba2SiO4:Tb3+ phosphor powders were characterized structurally and morphologically by employing X-ray diffraction (XRD) and Scanning electron microscopy (SEM) techniques. The photoluminescent characterization identified that the sample exhibits intense green photoluminescence (PL) emission with several peaks in the range (490−622 nm) which are attributed to the 5D4-7Fj transition of Tb3 + . The excitation spectrum identified that the sample has a broad excitation ranging from UV to visible (350−500 nm). Additionally, the CIE coordinates were calculated to determine its color purity. PL measurement revealed that the synrthesised phosphor shows significant overalapping with commonly used Polymers and small-molecules used in organic solar cells. The detailed structural, morphological and photoluminescence characterization revealed that the material is a potential candidate for for solid-state lighting and photovoltaic applications.

Here, we report a luminescent cathode buffer layer (CBL) for power conversion efficiency (PCE) enhancement of organic solar cells (OSCs). ZnO doped with Aluminum (Al) and Europium (Eu) was cast as CBL by a solution-processed method. CBL serves a dual purpose by acting both as a spectral conversion and an electron transporting layer. The luminescent ZnO:Al,Eu CBL layer has broad absorption spanning the ultraviolet (300–400 nm) spectrum, contributing to absorption enhancement. Moreover, the emission of CBL layer overlaps with the absorption of poly [N -9′-heptadecanyl-2,7-carbazole- alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) polymer thus elevating the overall absorption of the active layer and improving the photocurrent. With this ZnO:Al,Eu CBL in the inverted device configuration (ITO/CBL/active layer/MoOx/Al), an enhanced power conversion efficiency (PCE) of 6.9% was obtained while the device with pristine ZnO as CBL showed PCE of 5.9%. A blend of PCDTBT donor and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) acceptor was used as an active layer in both the cases. In ZnO:Al,Eu CBL layer, Al doping improves the conductivity, while Eu doping significantly enhances the emission in the visible region by down-shifting the incoming solar UV light to the visible range which overlaps with the absorption of PCDTBT polymer resulting in energy transfer and improved overall device efficiency. The findings of the study show the significance of luminescent ZnO:Al,Eu nanoparticle CBL in enhancing the performance of organic solar cells.

TiO2 NPs synthesized via aqueous route shows better photocatalytic activity as compare to doped TiO2 NPs. The presence of dopants inhibits the recombination of exciton. The photocatalytic activity of the nanomaterial have been reduced because of less adsorption sites are available for MB dye due to increase surface coverage of nanomaterial by increase in Cr loading and thus less degradation is shown by doped material. Undoped TiO2 nanoparticles shows complete degradation of MB in 90 min, whereas doped TiO2 takes 120 min for complete degradation. The results suggested as higher concentration of dopant material leads to reduction in photocatalytic efficiency.

Now a days, inorganic nanoparticles are gaining importance and are potential candidate in different organic electronic device application like (LEDs, PVs) due to their novel properties and confinement in Nano-dimensions. [1, 2]In the present work, we have compared the properties of titanium di oxide (TiO2) nanoparticles (NPs) synthesized by using two different chemical routes aqueous and ethanol respectively. These synthesized TiO2 nanoparticles have been characterized by X-ray diffraction spectroscopy (XRD) for phase confirmation. It was observed that synthesized nanoparticles are in anatase phase for both preparation routes.Morphological information was collected by scanning electron microscopy (SEM) which confirms that particles are almost spherical in shape and distributed uniformly which is further ensured by transmission electron microscopy (TEM). Dynamic light scattering (DLS) technique was also used for further confirmation of size distribution of as-synthesized nanoparticles. Optical properties w...