Atomistic origins of CH3NH3PbI3 degradation to PbI2 in vacuum

作者:Deretzis I*; Alberti A; Pellegrino G; Smecca E; Giannazzo F; Sakai N; Miyasaka T; La Magna A
来源:Applied Physics Letters, 2015, 106(13): 131904.
DOI:10.1063/1.4916821

摘要

We study the mechanisms of CH3NH3PbI3 degradation and its transformation to PbI2 by means of X-ray diffraction and the density functional theory. The experimental analysis shows that the material can degrade in both air and vacuum conditions, with humidity and temperature-annealing strongly accelerating such process. Based on ab initio calculations, we argue that even in the absence of humidity, a decomposition of the perovskite structure can take place through the statistical formation of molecular defects with a non-ionic character, whose volatility at surfaces should break the thermodynamic defect equilibria. We finally discuss the strategies that can limit such phenomenon and subsequently prolong the lifetime of the material.

  • 出版日期2015-3-30