Tin perovskites are emerging as promising alternatives to their lead-based counterparts for high-performance and flexible perovskite solar cells.However,their rapid crystallization often leads to inadequate film quali...Tin perovskites are emerging as promising alternatives to their lead-based counterparts for high-performance and flexible perovskite solar cells.However,their rapid crystallization often leads to inadequate film quality and poor device performance.In this study,the role of GeI_(2) as an additive is investigated for controlling the nucleation and crystallization processes of formamidinium tin triiodide(FASnI3).The findings reveal the preferential formation of a Ge-rich layer at the bottom of the perovskite film upon the introduction of GeI_(2).It is proposed that the initial formation of the Ge complex acts as a crystallization regulator,promoting oriented growth of subsequent FASnI3 crystals and enhancing overall crystallinity.Through the incorporation of an optimal amount of GeI_(2),flexible Sn perovskite solar cells with an efficiency of 10.8%were achieved.Furthermore,it was observed that the GeI_(2) additive ensures a remarkable shelf-life for the devices,with the rigid cells retaining 91%of their initial performance after more than 13800 h of storage in an N_(2) gas environment.This study elucidates the mechanistic role of GeI_(2) in regulating the nucleation and crystallization process of tin perovskites,providing valuable insights into the significance of additive engineering for the development of high-performance flexible tin perovskite solar cells.展开更多
基金funding from the European Union’s Horizon Europe research and innovation program under grant agreement no.101075605(SuPer-Tandem)financially supported by Swiss National Science Foundation(grant no.200021_213073)+3 种基金Swiss Federal Office of Energy(SFOE,grant no.SI/502549-01)partially financially supported by the National Natural Science Foundation of China(nos.62104163 and 62174112)the Natural Science Foundation of Sichuan Province(no.2022NSFSC1183)the China Scholarship Council(CSC)funding from the Ministry of Education of P.R.China.
文摘Tin perovskites are emerging as promising alternatives to their lead-based counterparts for high-performance and flexible perovskite solar cells.However,their rapid crystallization often leads to inadequate film quality and poor device performance.In this study,the role of GeI_(2) as an additive is investigated for controlling the nucleation and crystallization processes of formamidinium tin triiodide(FASnI3).The findings reveal the preferential formation of a Ge-rich layer at the bottom of the perovskite film upon the introduction of GeI_(2).It is proposed that the initial formation of the Ge complex acts as a crystallization regulator,promoting oriented growth of subsequent FASnI3 crystals and enhancing overall crystallinity.Through the incorporation of an optimal amount of GeI_(2),flexible Sn perovskite solar cells with an efficiency of 10.8%were achieved.Furthermore,it was observed that the GeI_(2) additive ensures a remarkable shelf-life for the devices,with the rigid cells retaining 91%of their initial performance after more than 13800 h of storage in an N_(2) gas environment.This study elucidates the mechanistic role of GeI_(2) in regulating the nucleation and crystallization process of tin perovskites,providing valuable insights into the significance of additive engineering for the development of high-performance flexible tin perovskite solar cells.
