Preparation Of Perovskite Solar Cells By Guanidine Hydrochloride Assisted Film Formation

In recent years,perovskite materials have been widely used in solar cells because of their excellent properties.In 2009,perovskite cells with an efficiency of 3.8% were first developed,and now the efficiency of solar cells has reached 25.2%.The photoelectric conversion efficiency of perovskite related solar cells has made great achievements.For perovskite solar devices,improving the quality of perovskite film is the key step to improve the performance of devices.The increase of N-H in hydrochloric acid can promote the formation of hydrogen bond network and the formation of films with higher coverage and flatness.In order to optimize the quality of perovskite films,we add the corresponding hydrochloric acid to the precursor solution of perovskite materials to form perovskite film crystals with a variety of cation mixtures,so as to improve the quality of perovskite films.Based on DMF,MAI and Pb I2,Based on DMF,MAI and Pb I2,the precursor solutions of perovskite materials were obtained by introducing various kinds of salts including MACl(methylamine hydrochloride),FACl(formamidine hydrochloride)and AGCl(aminoguanidine hydrochloride).High quality perovskite films were obtained by spin coating perovskite precursor solution and annealing spin coating.The morphology,structure and absorption properties of the prepared per ovskite films were characterized by scanning electron microscope,X-ray diffractometer,UV-VIS spectrophotometer and other equipment.According to the characterization results,it was found that after adding AGCl,the crystallinity of the perovskite films was improved,and the compactness and flatness became higher.The quality of perovskite optical absorption layer is optimized by annealing process.In this paper,the difference of the micro morphology of perovskite film under different annealing time and annealing temperature is compared.It is found that the best perovskite optical absorption layer can be obtained by introducing AGCl spin coating when the annealing time is 15 minutes and the annealing temperature is 100.In this paper,the conversion efficiency of perovskite devices with different salts as additives is studied.Among them,when AGCl is used as additive,the highest conversion efficiency of solar cell can reach 17.86% and the repeatability is good.In addition,the effects of annealing time and annealing temperature on the conversion rate of solar cell were studied.For AGCl additive,the optimal conversion efficiency of solar cell was obtained when annealing at 100 for 15 min.At the same time,by testing the related electrical properties of the battery device,this paper analyzes the relationship between the device and the film quality of perovskite.Based on the best quality of perovskite films prepared by adding AGCl,two other guanidine salts MGCl(methylguanidine hydrochloride)and DGCl(diaminoguanidine hydrochloride)with different N-H quantity were selected to prepare AGCl,MGCl and DGCl as additives to prepare large area perovskite inverted heterostructure solar cells.The experimental results show that the highest conversion efficiency of large area solar cell devices obtained by using DGCl as additive is 12.1%,which is significantly better than the efficiency of solar cells prepared by adding AGCl and MGCl respectively by 10.46% and 9.99%.Therefore,comparing the performance differences between the devices and analyzing the relationship between the device performance and the film forming quality of perovskite,the conclusion of this paper is: when the same functional group of hydrochloride is introduced,increasing the content of N-H in the hydrochloride can improve the conversion efficiency of perovskite inverted heterojunction solar energy cells.To sum up,the following conclusions are drawn: not only N-H on amino group,amidine group and guanidine group will affect the perovskite film,but also the same kind of hydrochloride,when the number of N-H changes,perovskite film will be optimized.This will provide some reference for the further development of solar cells and promote the industrial development of perovskite industry.