Black single crystals of lead-free perovskite Cs2Ag(Bi:Ru)Br6 with an intermediate band - Zhang, Zehao; Liu, Ganghong; Guo, Wenhui; Li, Xiangdong; Zhang, Yuqing; Wu, Cuncun; Qu, Bo; Shi, Jun-jie; Chen, Zhijian; Xiao, Lixin (MATERIALS ADVANCES, 2022)