Search

SnS thin films were synthesized using the spray pyrolysis method and then annealed at 350, 400, and 450°C. According to the crystallographic analysis, the obtained SnS thin films crystallized in the polycrystalline orthorhombic system. The grains measured 47, 66, and 37 nm for the samples annealed at 350, 400, and 450°C, respectively. SEM and AFM images indicate that the samples’ surfaces were completely covered. Thus, the grains of SnS nanostructures have a granular-like shape and vary in size depending on the annealing temperatures. The transmittance measurement shows that annealing the sample at 400 °C extends and improves its absorption range to 600 nm. The resulting band gap energies were 1.60 eV, 1.30 eV, and 2.55 eV for annealing at 350 °C, 400 °C, and 450 °C, respectively. Hall Effect measurements reveal that annealing SnS films at 400 °C enhances their electrical properties. The values of carrier mobility, conductivity, and carrier concentration are 1.678 ×105 Cm2/Vs, 9.756 ×10-5 Ω-1 cm-1, and 3.168 ×1010Cm-3, respectively. Additionally, the photocurrent response validates that all samples annealed at 350, 400, and 450 °C have p-type conductivity, with values of 13, 28, and 2.5 µA/Cm2, respectively. The best conductivity, carrier mobility, and photocurrent values are obtained by annealing at 400 °C. Therefore, SnS thin films can be an interesting choice for absorber layer applications in photovoltaic systems. [ABSTRACT FROM AUTHOR]

SnS nanostructures were prepared using the electrodeposition technique in aqueous solutions containing 0.1M of SnSO4 and Na2SO4. Three concentrations (0.05M, 0.10M, and 0.15M) of Na2SO4 were tested. The electrodeposition of SnS nanostructures on ITO substrates was investigated by cyclic voltammetry, chronoamperometry, SEM microscopy, and X-ray diffraction techniques. The concentration-dependent nucleation and growth mechanisms of electrodeposited SnS were analyzed using current transients. For the concentrations (0.05M and 0.10 M), the SnS films follow 3D growth in instantaneous nucleation mode. For a concentration of 0.15M, the SnS films start with progressive nucleation before switching to the instantaneous nucleation mode. The SnS nanostructures produced were found to be polycrystalline with an orthorhombic structure. XRD measurement shows that the preferred orientation of SnS nanostructures is in the (111) and (101) directions for the lower concentrations. SEM images reveal the 3D growth model of the samples, which is consistent with the electrochemical analysis. [ABSTRACT FROM AUTHOR]

Undoped Zinc oxide (ZnO) and erbium (Er) doped ZnO thin films have been grown on glass substrate by dip coating technique under alkaline conditions (pH 9). The pH was maintained at 9 for all prepared sols by controlling the amount of Monoethanolamine (MEA). The eff ;ects of Er doping concentration on the ZnO films properties was studied by using XRD, SEM, EDX, AFM, Raman spectroscopy, FTIR analysis and UV–vis spectrophotometer. The results showed that the incorporation of Er3+ under alkaline pH had a great effect on the ZnO properties. All samples exhibit a pure ZnO polycrystalline hexagonal wurtzite structure with a high crystalline quality. Homogenous, smooth and dense granular morphology nanostructures were revealed by AFM and SEM analysis. Raman spectroscopy and FTIR analysis confirm the formation of ZnO hexagonal wurtzite structure for samples. It was found that Er doping concentration enhance optical transmittance of ZnO based thin films. A red-shift was observed in the band gap of Er doped ZnO films with increasing Er concentration. The obtained results make EZO based thin films suitable for solar cells applications. [ABSTRACT FROM AUTHOR]

In this study, an optical scheme based on the measurement of light intensity and a proper orientation of the Fresnel Rhomb is successfully developed for simultaneous determination of the phase retardation and fast axis of a wave plate. The theoretical analysis of the principle of measuring the reflection-induced retardance of the Fresnel Rhomb and the phase retardation of a wave plate is given taking Stokes–Mueller Formalism as a mathematical tool. In this method, the fast axis position of the wave plate need not be determined in advance. In addition, the measured result is free of the intensity fluctuation of light source. An application example is also demonstrated. The measured result of the example is verified with an experiment. Some of the merits of the method, such as, a simple optical set-up, high stability and high accuracy, low cost and easier operation, are presented, and the validity of the method is demonstrated. [ABSTRACT FROM PUBLISHER]