It is necessary to evaluate the interactions between the different functional layers in optoelectronic devices to optimize device performance.Recently,the I-rich allinorganic perovskite CsPbI2 Br has attracted tremend...It is necessary to evaluate the interactions between the different functional layers in optoelectronic devices to optimize device performance.Recently,the I-rich allinorganic perovskite CsPbI2 Br has attracted tremendous attention for use in solar cell applications because of its suitable band gap and favorable photo and thermal stabilities.It has been reported that the undesirable phase degradation of the photoactiveαphase CsPbI2 Br to the non-perovskiteδphase could be triggered by high humidity.To obtain stable devices,it is thus important to protect CsPbI2 Br from moisture.In this paper,CuI,a non-hygroscopic p-type hole-transporting material,is found to induce the phase degradation ofα-CsPbI2 Br to theδ-CsPbI2 Br.The rate and extent of phase degradation of CsPbI2 Br are closely associated with the heating temperature and coverage of a Cu I granular capping layer.This discovery is different from the widely reported water-induced phase degradation of CsPbI2 Br.Our work highlights the importance of careful selection of hole-transporting materials during the processing of I-rich all-inorganic CsPbX3(X=Br,I)perovskites to realize high-performance optoelectronic devices.展开更多
基金supported primarily by the National Key Research and Development Program of China(2018YFA0209303)the National Natural Science Foundation of China(U1663228,51902153,51972165 and 61377051)the Fundamental Research Funds for the Central Universities of China。
文摘It is necessary to evaluate the interactions between the different functional layers in optoelectronic devices to optimize device performance.Recently,the I-rich allinorganic perovskite CsPbI2 Br has attracted tremendous attention for use in solar cell applications because of its suitable band gap and favorable photo and thermal stabilities.It has been reported that the undesirable phase degradation of the photoactiveαphase CsPbI2 Br to the non-perovskiteδphase could be triggered by high humidity.To obtain stable devices,it is thus important to protect CsPbI2 Br from moisture.In this paper,CuI,a non-hygroscopic p-type hole-transporting material,is found to induce the phase degradation ofα-CsPbI2 Br to theδ-CsPbI2 Br.The rate and extent of phase degradation of CsPbI2 Br are closely associated with the heating temperature and coverage of a Cu I granular capping layer.This discovery is different from the widely reported water-induced phase degradation of CsPbI2 Br.Our work highlights the importance of careful selection of hole-transporting materials during the processing of I-rich all-inorganic CsPbX3(X=Br,I)perovskites to realize high-performance optoelectronic devices.
