Research On Inorganic Non Lead Perovskite Solar Cells Based On Cs₃Sb₂Cl_xI_9-x

Lead based perovskite solar cells have developed rapidly in recent years,and the photoelectric conversion efficiency has reached more than 25%.However,the lead element contained in these solar cells will inevitably cause environmental pollution,so the research of non lead-based environment-friendly perovskite solar cells is very necessary.At present,non lead antimony-based and bismuth-based perovskite solar cells are expected to replace lead-based solar cells.However,they have some problems,such as immature process,low efficiency,poor stability and so on.This paper mainly focuses on the research of antimony-based perovskite solar cells,which not only reduces the preparation cost of devices,but also improves the photoelectric conversion efficiency of such devices.The main innovative achievements of this paper are as follows:(1)Perovskite absorption layer and solar cell based on Cs₃Sb₂Cl_xI_9-x were prepared by using anisole,isopropanol and chlorobenzene as anti-solvent respectively.The effects of different anti-solvents as auxiliary means on the photovoltaic properties of the films and solar cells were studied.The results show that the films prepared with anisole as an anti-solvent have larger grain size,denser morphology,better crystallinity,higher light absorption and the highest photoluminescence intensity.In addition,the solar cell prepared by anisole has the highest recombination resistance,which reduces the recombination ability of carriers and increases the photoelectric conversion efficiency of the solar cell.Finally,the solar cell also uses low-cost carbon as the electrode and achieves a photoelectric conversion efficiency of 2.07%.(2)The new absorption layer film synthesized by Rb doped Cs₃Sb₂Cl_xI_9-x further increases the photoelectric conversion efficiency of solar cells.This paper also discussed the effects of Rb doping on the properties of Cs₃Sb₂Cl_xI_9-x thin films and corresponding solar cells.The results show that compared with the original undoped films,the 5%Rb doping concentration makes the Cs₃Sb₂Cl_xI_9-x films more effectively transform to two-dimensional structure and improve the carrier transport capacity.At the same time,the new film shows a denser surface and larger grain size,and has the strongest light absorption.Moreover,Cs₃Sb₂Cl_xI_9-x film with 5%Rb doping concentration has greater work function,driving ability and longer carrier life,so that the internal carriers can be separated and transmitted more effectively.This method reduces the defect density and carrier recombination rate,which is helpful to increase the performance of solar cells.(3)The solar cells based on the Rb_0.15Cs_2.85Sb₂Cl_xI_9-x film were prepared using Nb₂O₅,Ti O₂ and Sn O₂ as different electron transport layers,and the effects of different electron transport layers on solar cells'performance were explored.The characterization result shows that the Rb_0.15Cs_2.85Sb₂Cl_xI_9-x film has the smallest conduction band offset with the Nb₂O₅ as the electron transport layer,indicating that this combination has the lowest ability of interface charge recombination.Eventually,solar cells with Nb₂O₅ as the electron transfer layer and Rb_0.15Cs_2.85Sb₂Cl_xI_9-x film as the absorption layer achieved a higher efficiency(2.46%).