Point Defects at Grain Boundaries Can Create Structural Instabilities and Persistent Deep Traps in Metal Halide Perovskites

Metal halide perovskites (MHPs) have attracted strong interest for a variety of applications due to their low cost and excellent performance, attributed largely to favorable defect properties. MHPs exhibit complex dynamics of charges and ions that are coupled in unusual ways. Focusing on a combination of two common MHP defects,