A Novel Ge-Doping Approach for Grain Growth and Recombination Suppression in Buffer-Free CIGSe Solar Cells. - Jia, Mengyao; Zhuang, Daming; Zhao, Ming; Wu, Zhihao; Han, Junsu; He, Yuan; Zhou, Jihui; Baranova, Maria; Lu, Wei; Gong, Qianming (Materials (1996-1944), 2026)