Identification of lead vacancy defects in lead halide perovskites.

ABSTRACT: Perovskite photovoltaics advance rapidly, but questions remain regarding point defects: while experiments have detected the presence of electrically active defects no experimentally confirmed microscopic identifications have been reported. Here we identify lead monovacancy (V_Pb) defects in MAPbI₃ (MA = CH₃NH₃⁺) using positron annihilation lifetime spectroscopy with the aid of density functional theory. Experiments on thin film and single crystal samples all exhibited dominant positron trapping to lead vacancy defects, and a minimum defect density of ~3 × 10¹⁵ cm^-3 was determined. There was also evidence of trapping at the vacancy complex [Formula: see text] in a minority of samples, but no trapping to MA-ion vacan

SUBMITTER: Keeble DJ 

PROVIDER: S-EPMC8458286 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature