Solar Cells: Phosphonium Halides as Both Processing Additives and Interfacial Modifiers for High Performance Planar‐Heterojunction Perovskite Solar Cells (Small 27/2015)

Organic halide salts are successfully introduced by F. Huang, H.-L. Yip, and co-workers as a processing additive to modulate the growth kinetics of perovskite light-absorbing films. Phosphonium halides with bulky aromatic substituents are found to be the most efficient at improving perovskite film coverage and crystallinity. Moreover, on page 3344, phosphonium halides can be used as an interfacial n-dopant to improve the electrical properties of cathode contacts. Perovskite solar cells incorporating organic halides as processing additives and interfacial modifiers show significant device performance improvement.