Research On Light-absorbing Materials And Devices Of Carbon-based All-Inorganic Perovskite Solar Cells

Carbon-based all-inorganic perovskite solar cells have attracted much attention due to their excellent stability under high temperature and strong ultraviolet conditions,as well as their simple and low-cost manufacturing process,choosing suitable all inorganic perovskite materials as the light absorption layer of carbon based all-inorganic perovskite solar cells is the premise to obtain higher power conversion efficiency.In this paper,simple solution methods are used to prepare different inorganic perovskite films,carbon-based all-inorganic perovskite solar cells are prepared with these films,the feasibility of the application of inorganic CsPbIxBr3-x perovskite and lead-free Ag-Bi-I perovskite materials in carbon-based perovskite solar cells has also been explored.In addition,the feasibility of the application of carbon-based all-inorganic perovskite cells with a simple structure without a hole/electron transport layer is further studied.Aiming to achieve the purpose of improving the performance of carbon-based all-inorganic perovskite solar cells by means of process modulation and interface modification.The main contents are as follows:1)For the first time,the intermediate phase halide exchange method is used to prepare high-quality CsPbBr3 thin films and their carbon-based perovskite solar cells,The mixture of CH3NH3Br and a trace amount of CsBr was used as the methanol solution,which react with CsPbIBr2 perovskite thin films to promote the rapid crystallization of CsPbBr3,and enhance the work function of the CsPbBr3 material so that it matches the energy band between the carbon electrode,so as promote the separation and transport of charge carriers in the perovskite solar cell.The carbon-based CsPbBr3 perovskite solar cells prepared with CsBr modification achieve the best PCE of 7.34%,which is comparable to the CsPbBr3 perovskite solar cells prepared by the traditional two-step process.2)High quality lead-free Ag2BiI5 film were prepared by high-pressure air-blowing method for the first time,which improved the coverage and crystallinity of Ag2BiI5 films.The carbon-based all-inorganic lead-free rudorffite solar cell based on this high quality Ag2BiI5 film achieved an optimized PCE of 0.71%,and the high open circuit voltage(Voc)of 0.77 V is the highest in the same period,which proved the great feasibility of constructing a leadfree solar cell with a simplified structure.3)Choose the CsPbIBr2 material with high energy conversion efficiency and stability in the inorganic CsPbIxBr3-x perovskite to construct a simple structure carbon-based allinorganic perovskite solar cell without ETL,HTL,and noble metal electrodes,The work function of FTO is reduced by introducing PEI,which makes the energy level between FTO and CsPbIBr2 film more matched.The open-circuit voltage(Voc)of the device after interface modification by PEI reaches 1.05V,the fill factor(FF)reaches 48.6%,and the PCE of the optimal device of 6.1%is obtained,which proved the application feasibility of simple structure carbon-based all-inorganic perovskite solar cells.