Preparation And Performance Optimization Of Sb₂Se₃ Thin Film Solar Cells

Sb₂Se₃ thin films have been successfully deposited on the surface of quartz and FTO glass by vacuum thermal evaporation.The structure,morphology,composition and optoelectric properties of Sb₂Se₃ films with different deposition temperatures and different film thicknesses were characterized and analyzed.The films were analyzed using X-ray diffraction,high resolution Raman spectrometer,scanning electron microscope,semiconductor parameter tester,UV-near infrared spectrometer and other technical means.The experimental results show that the Sb₂Se₃ thin film with 700 nm of film thickness fabricated 300? of substrate temperature have the optimum crystal orientation and good crystallinity.What's more,the films prepared under this condition have smaller optical band gap,very low transmittance at visible light wavelength range and higher conductivity.CdS/Sb₂Se₃ thin film solar cells were fabricated using Sb₂Se₃ thin film as absorbed layer and CdS thin film prepared by water bath deposition as buffer layer.The results show that the CdS/Sb₂Se₃ thin film solar cell prepared by Sb₂Se₃ thin film with 300? of deposition temperature and 700 nm of thickness has the best optoelectric conversion efficiency,its efficiency is about 1.57%.In order to further improve the performance of the solar cells and prevent microvoids in the CdS layer from damaging the pn junction,a high-resistance transparent layer,i.e.SnO₂ layer was introduced into the CdS/Sb₂Se₃ thin film solar cell.The SnO₂ films were obtained by oxidation of Sn films.The experimental results show that the SnO₂ films oxidated at 500? have the best light transmittance,the lowest optical absorption coefficient and the maximum optical band gap.Therefore,it is the best choice for the preparation of high-resistance transparent layer.The optoelectrical conversion efficiency of the CdS/Sb₂Se₃ thin film solar cells is increased to 1.89%,increased by about 20% after the introduction of the SnO₂ layer.The reason is that the transparent high resistivity layer can effectively prevent the destruction of the pn junction caused by the direct contact between the Sb₂Se₃ film and the FTO layer and simultaneously reduce the density of the interface state and the diffusion of impurity ions.