Interactions Between 2D Halide Perovskite Materials and Methylamine Vapor

The structural tunability of halide perovskites offers exciting potential for their use as photovoltaic materials and as semiconductors in diverse applications. We investigate 2-dimensional Ruddlesden-Popper phase halide perovskite structural stability by the intercalation-deintercalation of methylamine gas. By manipulating the organic spacer, we investigate the relative binding strength in comparison to methylamine. We find that in some 2D perovskite systems, deintercalation of the methylamine gas is incomplete and appears to result in the formation of some CH3NH3PbI3; however, materials featuring other organic spacers show the initial formation of A(2)(CH3NH3)(n-1)PbnI3n+1 materials with n = 2 with subsequent reversible intercalation-deintercalation of methylamine, indicating stronger binding with the lead halide octahedral sheets.