Research On Halogen Regulation And Solar Cells Preparation Based On Two-dimensional Perovskite Materials

Due to the excellent optoelectronic properties and simple preparation process,perovskite materials have received widespread attention from researchers in recent years.Among them,the development of perovskite solar cells is extremely rapid.In just over ten years,the device efficiency has climbed from 3.8%to more than 25%.However,the traditional three-dimensional perovskite material has the problem of inadequate stability,which makes the commercial application of three-dimensional perovskite solar cells a long way off in the future.As a member of the perovskite material family,the two-dimensional perovskite material inherits many of the advantages of three-dimensional perovskite material while also having better stability,which makes it a better application prospect.At present,the research of two-dimensional perovskite mostly focuses on the replacement of organic amines and the optimization of the preparation process,but there are few related researches on the regulation of halogen ions.The major achievements of Br element doping in three-dimensional perovskite materials give usgreat expectations for its role in two-dimensional perovskite.This article focuses on the effects of Br element doping on the characteristics of two-dimensional perovskite films,the performance of solar cells and internal carrier recombination.The details are as follows:?1?BA₂MA₄Pb₅(I_1-xBr_x)₁₆ films were prepared by hot-casting.Through SEM,AFM,XED,GIWAXS and other related tests,two-dimensional perovskite films with different bromine doping ratios were characterized.The results showed that 10%bromine doping was the optimal ratio.With this ratio of doping,the morphology of the film is significantly improved and the crystals grow vertically to the substrate.In addition,the carrier life is increased and internal defects are reduced.?2?The complete solar cells were prepared using BA₂MA₄Pb₅(I_1-x-x Br_x)₁₆ films with different doping ratios as light absorbing layers,and related performance tests were performed.It was found that the device doped with 10%bromine has a maximum efficiency of 12.4%and an average efficiency of 12.15%.Compared with an undoped device with a maximum efficiency of 3.66%and an average efficiency of 3.08,the performance has been significantly improved.At the same time,the devices doped with10%bromine also had lower hysteresis.It was confirmed that bromine doping can significantly improve device performance.?3?The performance stability of the without Br doping and 10%Br doping devices?x=0 and x=0.10?were tested under continuous light,continuous heating,and unpackaged placement in air,respectively.The results showed that 10%bromine-doped devices exhibited stronger stability.It was confirmed that the doping of bromine element can improve the stable behavior of the device.At the same time,dark current and ideal factor tests were performed on the two devices.The results showed that the 10%bromine doping can significantly reduce the carrier recombination of the devices.