Title: Photodecomposition in Methylammonium Lead Triiodide Thin Films

Abstract: Organic-inorganic hybrid perovskites have shown remarkable photovoltaic properties while being solution and low-temperature processable. However, long-term applications are limited by instability arising from the material’s surface and photoexcitation. With above bandgap excitation Raman spectroscopy, the photodegradation process of methylammonium lead triiodide (MAPbI 3 ) was monitored. Revealing two stages of structural change, one where subtle structural disruption occurs below a photoexcitation density threshold, while above this threshold, photodegradation scales linearly. It is also shown that the decomposition of MAPbI 3 is accelerated by the amount of surfaces present with materials of varying grain sizes, illustrating their prominent role in the structural transformation process.

Host: Sharonda LeBlanc