The advancement in a power conversion efficiency(PCE)to reach 25%,the inorganic perovskites are being explored intensively as promising optoelectronic materials due to their excellent photovoltaic performance,i.e.,the...The advancement in a power conversion efficiency(PCE)to reach 25%,the inorganic perovskites are being explored intensively as promising optoelectronic materials due to their excellent photovoltaic performance,i.e.,thermal stability and efficiency.Lately,the inorganic cesium lead halide perovskite is studied to show enhanced light absorption,however,it suffers from the phase separate into I-rich and Br-rich phase which leads to poor film quality due to difference of electronegativity.Herein,we propose a unique solution of controlling the rate of solvent volatilization followed by gel method to inhibit phase separation effectively to obtain the homogenous and pinhole-free CsPbIBr2 films with high crystalline quality.In this study,an inverted planar device based on a light absorber of CsPbIBr2 is prepared to achieve a power conversion efficiency of 8.8%(maintain a stabilized value of 8%in ambient air conditions).Surprisingly,the optimized cell without encapsulation shows excellent long-term stability,as it maintained 90%initial efficiency over 500 h and controlled storage at around 45%relative humidity and 25℃.展开更多
基金the National Natural Science Foundation of China(Nos.11174071,11304088,and 51372180)Special Technical Innovation Project of Hubei Province(Nos.2016AAA035 and 20178ACA088).
文摘The advancement in a power conversion efficiency(PCE)to reach 25%,the inorganic perovskites are being explored intensively as promising optoelectronic materials due to their excellent photovoltaic performance,i.e.,thermal stability and efficiency.Lately,the inorganic cesium lead halide perovskite is studied to show enhanced light absorption,however,it suffers from the phase separate into I-rich and Br-rich phase which leads to poor film quality due to difference of electronegativity.Herein,we propose a unique solution of controlling the rate of solvent volatilization followed by gel method to inhibit phase separation effectively to obtain the homogenous and pinhole-free CsPbIBr2 films with high crystalline quality.In this study,an inverted planar device based on a light absorber of CsPbIBr2 is prepared to achieve a power conversion efficiency of 8.8%(maintain a stabilized value of 8%in ambient air conditions).Surprisingly,the optimized cell without encapsulation shows excellent long-term stability,as it maintained 90%initial efficiency over 500 h and controlled storage at around 45%relative humidity and 25℃.