Efficient Homojunction Tin Perovskite Solar Cells Enabled by Gradient Germanium Doping

Zhenzhu Zhao, Mulin Sun, Yuyang Ji, Kaitian Mao, Zongming Huang, Chengjian Yuan, Yuqian Yang, Honghe Ding, Yingguo Yang, Yu Li^*, Wenjing Chen^*, Junfa Zhu, Jing Wei, Jixian Xu, Watcharaphol Paritmongkol, Antonio Abate, Zhengguo Xiao, Lixin He^*, Qin Hu^*