jz7b00055_si_001.pdf (10.86 MB)
Charge Carrier Trapping at Surface Defects of Perovskite Solar Cell Absorbers: A First-Principles Study
journal contribution
posted on 2017-01-27, 00:00 authored by Hiroki Uratani, Koichi YamashitaThe
trapping of charge carriers at defects on surfaces or grain
boundaries is detrimental for the performance of perovskite solar
cells (PSCs). For example, it is the main limiting factor for carrier
lifetime. Moreover, it causes hysteresis in the current–voltage
curves, which is considered to be a serious issue for PSCs’
operation. In this work, types of surface defects responsible for
carrier trapping are clarified by a comprehensive first-principles
investigation into surface defects of tetragonal CH3NH3PbI3 (MAPbI3). Considering defect formation
energetics, it is proposed that a Pb-rich condition is preferred to
an I-rich one; however, a moderate condition might possibly be the
best choice. Our result paves the way for improving the performance
of PSCs through a rational strategy of suppressing carrier trapping
at surface defects.