Study On Performance Optimization Of High Efficiency Perovskite Solar Cells Based On Inorganic Hole Transport Layer

Perovskite solar cell has the excellent characteristics of low cost and high efficiency,which attracts the attention of photovoltaic researchers.In just ten years,its highest conversion efficiency is 25.2%,which is equivalent to Si based solar cell.However,the poor device stability limits the commercial application of perovskite solar cells.The organic hole transport materials for the solar cells are expensive and have poor stability.Inorganic hole transport materials have the advantages of low preparation cost,simple process and good stability.Therefore,the research and development of inorganic hole transport materials matching with perovskite absorption materials is one of the important ways to improve the stability of perovskite solar cells.At present,many researchers have done a lot of research on inorganic transport layer materials,but the conversion efficiency of perovskite solar cells is less than 20%from theory to experiment.In this paper,by means of device simulation,inorganic hole materials are used to replace organic hole materials,and the device structure and interface modification are respectively optimized to obtain high-efficiency solar cell device parameters,which will provide important theoretical guidance for later experimental preparation,and have important guiding significance for the design of high-efficiency and stable perovskite solar cells in the future.The main research contents and results are as follows:（1）CH₃NH₃PbI₃/CsSnI₃ all perovskite heterojunction solar cells were designed.The basic structure of the device is FTO/TiO₂/CH₃NH₃PbI₃/CsSnI₃/C,in which CsSnI₃ is the hole transport layer and also the absorption layer.The optimal parameters of the solar cell were Voc=1.08 V,Jsc=25.33 mA/cm²,FF=79.27%,PCE=21.64%from the aspects of CsSnI₃ thickness,defect state density,doping concentration and band gap width.By comparing the performance of perovskite solar cells with and without hole transport layer,it is proved that CsSnI₃ can effectively increase the absorption spectrum to near infrared region,and the conversion efficiency of solar cells is also significantly increased.（2）The device characteristics of perovskite solar cells with CuI as hole transport layer are studied.Using CuI as the hole transport material,the device conversion efficiency can reach 20.84%.The results show that the optimal thickness of the absorption layer and CuI layer respectively are 500 nm and 30 nm,and the defect density of the absorption layer has a great influence on the device performance.The doping concentration of CH₃NH₃PbI₃should not exceed 10¹⁶cm^-3and the optimum doping concentration of CuI is about 10¹⁹cm^-3.Finally,the influence of temperature on the performance of solar cells is studied.The results show that the performance of solar cells will decline with the increase of temperature.