Cation engineering on lead iodide perovskites for stable and high-performance photovoltaic applications

Incorporation of Cs+ and/or HC(NH2)2+ cations to prototypical CH3NH3PbI3 enhances chemical stabilities of alloyed perovskites under humidity and elevated temperature conditions, while adoptions of cations with longer alkyl chains, such as C4H9NH3+, together with CH3NH3+ can lead to out-of-plane alignments of highly-crystalline 2-D perovskites with increased stability and favored charge transport. 143