Role of Charge-Trapping Iodine Frenkel Defects for Hysteresis in Organic-Inorganic Hybrid Perovskite from First-Principles Calculations

Abstract

First-principles density functional theory calculations are employed to provide insight into charge-trapping phenomena that lead to the I-V hysteresis in CH3NH3PbI3 (MAPbI(3)). Energetic studies, variation in electronic structure, and charge-density analyses show that two types of iodine Frenkel defects can be stabilized by trapping excess charge carriers in MAPbI(3). As a result, these defects cause the phenomena of slow charge trapping and detrapping. Based on this insight, we propose several possible ways to eliminate charge trapping in devices based on MAPbI(3).