A crystal capping layer for formation of black-phase FAPbI₃ perovskite in humid air

Yu Zou, Wenjin Yu, Haoqing Guo, Qizhi Li, Xiangdong Li, Liang Li, Yueli Liu, Hantao Wang, Zhenyu Tang, Shuang Yang, Yanrun Chen, Bo Qu, Yunan Gao, Zhijian Chen, Shufeng Wang, Dongdong Zhang, Yihua Chen, Qi Chen, Shaik M. Zakeeruddin, Yingying PengHuanping Zhou, Qihuang Gong, Mingyang Wei, Michael Grätzel, Lixin Xiao