Study On Electron Transport Layer And Photoelectric Properties Of Sn Modified TiO₂ In Atmospheric Environment

Energy issues have attracted wide attention.Thus the development of sustainable clean energy is very important.Solar energy is widely studied for rich content,clean and convenient advantages among the renewable energy.Perovskite solar cells?PSCs?based on organic metal halide CH₃NH₃PbX₃?MAPbX₃,X=Br,I,Cl?have become the focus of study as the third generation of photovoltaic devices.TiO₂ is widely used as an electron transport layer material.However,there are some defects in TiO₂ itself,such as low electron transfer rate,low electron acquisition rate and oxygen vacancies.Therefore,it is necessary to modify TiO₂ to improve photoelectric properties.In this paper,the structure of TiO₂/SnO₂ and Sn doping are used to improve the photoelectric properties.In this study,TiO₂ precursor solution was prepared by HI and TiO₂ film was prepared at 150?.The results show that TiO₂ film prepared by HI has higher visible light transmittance,lower oxygen vacancy content and defect state density.TiO₂/SnO₂ double electron layer structure improves the electron acquisition ability,migration ability and decreases transport resistance.PSCs were made in atmospheric environment,which highest photoelectric conversion efficiency?PCE?reaches 16.74%,and the hysteresis effect is reduced.In addition,the device maintains the initial PCE of 91%during 1400 h in the air environment.The thermal stability and light stability are good.Sn ion was doped TiO₂ to prepare TiO₂-PSCs,which reduced the technological complexity.The experimental results show that Sn ion doping TiO₂ could reduce oxygen vacancy,defect states and increase the ability of electron acquisition.PSCs prepared in the air environment have good reproducibility,which the highest PCE reaching 17.76%and the hysteresis effect reduced.The PCE can maintain the initial92%after 1400 h in air condition.PSCs also have good stability under 100?heating and AM 1.5 G light condition.