Influence of substrate temperature on physical properties of MnSbInS4 thin films prepared by a simplified spray pyrolysis technique for photovoltaic applications

726-734MnSbInS4 multi-component semiconductor thin films are prepared by chemical spray pyrolysis on glass substrates at various substrate temperatures ranging from 250-400 °C with a constant spray time (5mins). The structural, morphological, optical and electrical properties of the thin films are investigated through different techniques such as X-ray diffraction (XRD), electron diffraction spectroscopy (EDS), UV-Vis absorption spectroscopy and four probe method. The X-ray spectra reveal that the MnSbInS4 films are polycrystalline in nature with a cubic spinel structure having (220) plane as the preferred orientation. The energy dispersive analysis by X-ray (EDS) studies confirm the presence of Mn, In, Sb and S in the film grown at a substrate temperature of 250 °C. Optical measurements allow us to determine the absorption coefficient which is as high as (1.22 x 105 cm-1) at 250 ºC indicating that MnSbInS4 compound has an absorbing property favorable for applications in solar cell devices. It is interesting to note that the structural homogeneity and crystallinity of the films is improved due to the decrease in absorption coefficient (α) and extinction coefficient (k) with an increase of substrate temperature. The observations from photoluminescence measurements reveal that the photoemission is mainly due to the donar-acceptor pair transitions. Moreover, from the electrical studies, it is observed that the electrical resistivity (ρ ) is strongly affected by substrate temperature and the lowest resistivity (ρ = 4.77 x 103 Ω m ) is obtained for the film grown at 400 ºC. Stylus profilometer was used to measure the film thickness and the values range between 768 nm (250 °C) to 617 nm (400 °C). This indicates that, as the substrate temperature increases, the thickness of the film decreases. Other important parameters like micro-strain (ε) and dislocation density (δ) which are commonly used to describe the structural analysis are also presented

Influence of substrate temperature on physical properties of MnSbInS4 thin films prepared by a simplified spray pyrolysis technique for photovoltaic applications

MnSbInS4 multi-component semiconductor thin films are prepared by chemical spray pyrolysis on glass substrates at various substrate temperatures ranging from 250-400 °C with a constant spray time (5mins). The structural, morphological, optical and electrical properties of the thin films are investigated through different techniques such as X-ray diffraction (XRD), electron diffraction spectroscopy (EDS), UV-Vis absorption spectroscopy and four probe method. The X-ray spectra reveal that the MnSbInS4 films are polycrystalline in nature with a cubic spinel structure having (220) plane as the preferred orientation. The energy dispersive analysis by X-ray (EDS) studies confirm the presence of Mn, In, Sb and S in the film grown at a substrate temperature of 250 °C. Optical measurements allow us to determine the absorption coefficient which is as high as (1.22 x 105 cm-1) at 250 ºC indicating that MnSbInS4 compound has an absorbing property favorable for applications in solar cell devices. It is interesting to note that the structural homogeneity and crystallinity of the films is improved due to the decrease in absorption coefficient (α) and extinction coefficient (k) with an increase of substrate temperature. The observations from photoluminescence measurements reveal that the photoemission is mainly due to the donar-acceptor pair transitions. Moreover, from the electrical studies, it is observed that the electrical resistivity (ρ ) is strongly affected by substrate temperature and the lowest resistivity (ρ = 4.77 x 103 Ω m ) is obtained for the film grown at 400 ºC. Stylus profilometer was used to measure the film thickness and the values range between 768 nm (250 °C) to 617 nm (400 °C). This indicates that, as the substrate temperature increases, the thickness of the film decreases. Other important parameters like micro-strain (ε) and dislocation density (δ) which are commonly used to describe the structural analysis are also presented

Influence of Mg Doping on ZnO Nanoparticles for Enhanced Photocatalytic Evaluation and Antibacterial Analysis

Abstract In this research, a facile co-precipitation method was used to synthesize pure and Mg-doped ZnO nanoparticles (NPs). The structure, morphology, chemical composition, and optical and antibacterial activity of the synthesized nanoparticles (NPs) were studied with respect to pure and Mg-doped ZnO concentrations (0–7.5 molar (M) %). X-ray diffraction pattern confirmed the presence of crystalline, hexagonal wurtzite phase of ZnO. Scanning electron microscope (SEM) images revealed that pure and Mg-doped ZnO NPs were in the nanoscale regime with hexagonal crystalline morphology around 30–110 nm. Optical characterization of the sample revealed that the band gap energy (E g) decreased from 3.36 to 3.04 eV with an increase in Mg2+ doping concentration. Optical absorption spectrum of ZnO redshifted as the Mg concentration varied from 2.5 to 7.5 M. Photoluminescence (PL) spectra showed UV emission peak around 400 nm. Enhanced visible emission between 430 and 600 nm with Mg2+ doping indicated the defect density in ZnO by occupying Zn2+ vacancies with Mg2+ ions. Photocatalytic studies revealed that 7.5% Mg-doped ZnO NPs exhibited maximum degradation (78%) for Rhodamine B (RhB) dye under UV-Vis irradiation. Antibacterial studies were conducted using Gram-positive and Gram-negative bacteria. The results demonstrated that doping with Mg ions inside the ZnO matrix had enhanced the antibacterial activity against all types of bacteria and its performance was improved with successive increment in Mg ion concentration inside ZnO NPs