Study On The Photoelectric Performance Of Perovskite Solar Cells Based On Interface Modification

Perovskite materials have excellent photoelectric properties,such as high carrier mobility,high light absorption coefficient,and simple process,making them attractive in the field of solar cells.The traditional low-temperature liquid phase two-step synthesis of perovskite thin films has shortcomings such as multiple defects and energy level mismatches,which hinder the further improvement of energy conversion efficiency of perovskite solar cells.Based on this,this article adopts two interface modification strategies,namely,the introduction of rubidium chloride（RbCl）interface layer onto the tin oxide（SnO2）electron transport layer and the introduction of pyridine trifluoromethanesulfonate（PDTF）interface layer onto the perovskite film,to eliminate bulk phase defects and interface defects in the perovskite film,reduce the density of defect states,optimize the interface energy level structure,and improve the film formation quality of the three cation perovskite film,The energy level arrangement structure of the device is optimized,and the photoelectric conversion efficiency and stability of the perovskite solar cell are improved.The specific research content is as follows:1.Regulation of the buried interface between the SnO₂ electron transport layer and the perovskite thin film.By introducing a rubidium chloride（RbCl）interface layer onto the tin oxide（SnO2）electron transport layer,the interface energy level structure is effectively regulated.The research shows that the prepared RbCl interface layer can not only effectively passivate the surface defects of SnO2,but also promote the growth of perovskite crystals during the preparation of perovskite thin films,effectively passivate the lower surface defects of perovskite thin films,reduce the density of trapped states of the perovskite layer,and improve the quality of perovskite thin films.In addition,the RbCl interface layer can reduce the SnO2 work function from 4.74 eV to 4.53 eV,optimizing the interface energy level structure,thereby promoting effective carrier transport.Under these effects,the non radiative recombination of photogenerated carriers at the interface is effectively suppressed,the open circuit voltage is significantly increased to 1.11 V,and the device performance is significantly improved to 21.64%.2.Interface regulation between the hole transport layer and the perovskite thin film.The introduction of pyridine trifluoromethanesulfonate（PDTF）interfacial layer onto perovskite films significantly affects the growth of perovskite films.The research shows that the trifluoromethanesulfonic acid and pyridine groups in PDTF passivate the vacancy defects of Pb and I in perovskite films,the density of defect states of perovskite thin films varies from 1.46×1015 cm-3 reduced to 1.21×1015 cm-3,thereby inhibiting the non radiative recombination of carriers.By adjusting the concentration of PDTF,the device performance was improved from 21.14%to 22.32%.In addition,the introduction of PDTF will form a hydrophobic layer on the surface of the perovskite film,which can prevent the invasion of water molecules into the perovskite film in the environment,and still maintain an initial efficiency of 85%after 30 days in air conditions.