Nickel-Doped Graphite and Fusible Alloy Bilayer Back Electrode for Vacuum-Free Perovskite Solar Cells
Mengyuan Li, So Yeon Park, Jianxin Wang, Ding Zheng, Owen Sayler Wostoupal, Xudong Xiao, Zhenzhen Yang, Xun Li, Benjamin T. Diroll, Tobin J. Marks, Kai Zhu, Tao Xu
Abstract
With the rapid development of perovskite solar cells (PSCs), lowering fabrication costs for PSCs has become a prominent challenge for commercialization. At present, gold is commonly used as the back metal electrode in state-of-the-art n-i-p structured PSCs due to its compatible work function, chemical inertness, and high conductivity. However, the high cost of gold and the expensive and time-consuming vacuum-based thin-film coating facilities may impede large-scale industrialization of PSCs. Here, we report a bilayer back electrode configuration consisting of an Ni-doped natural graphite layer with a fusible Bi-In alloy. This back electrode can be deposited in a vacuum-free approach and enables PSCs with a power conversion efficiency of 21.0%. These inexpensive materials and facile ambient fabrication techniques provide an appealing disruptive solution to low-cost PSC industrialization.