A Bifunctional Saddle-Shaped Small Molecule as a Dopant-Free Hole Transporting Material and Interfacial Layer for Efficient and Stable Perovskite Solar Cells

Xue Lai, Fei Meng, Qian Qian Zhang, Kai Wang, Gongqiang Li, Yaping Wen, Haibo Ma, Wenhui Li, Xianqiang Li, Aung Ko Ko Kyaw, Kai Wang, Xiao Wei Sun, Mengzhen Du, Xiao Guo, Jianpu Wang, Wei Huang