Identification of lead vacancy defects in lead halide perovskites
Artikel i vetenskaplig tidskrift, 2021

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 (VPb) 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 (VPbVI)− in a minority of samples, but no trapping to MA-ion vacancies was observed. Our experimental results support the predictions of other first-principles studies that deep level, hole trapping, VPb2−, point defects are one of the most stable defects in MAPbI3. This direct detection and identification of a deep level native defect in a halide perovskite, at technologically relevant concentrations, will enable further investigation of defect driven mechanisms.

Författare

D. J. Keeble

University of Dundee

Julia Wiktor

Chalmers, Fysik, Kondenserad materie- och materialteori

Sandeep K. Pathak

University of Oxford

Indian Institute of Technology Delhi

Laurie J. Phillips

University of Liverpool

Marcel Dickmann

Technische Universität München

Universität Der Bundeswehr München

Ken Durose

University of Liverpool

Henry J. Snaith

University of Oxford

Werner Egger

Universität Der Bundeswehr München

Nature Communications

2041-1723 (ISSN)

Vol. 12 1 5566

Atomistisk design av fotoadsorberande material

Vetenskapsrådet (VR) (2019-03993), 2020-01-01 -- 2023-12-31.

Ämneskategorier

Oorganisk kemi

Atom- och molekylfysik och optik

Den kondenserade materiens fysik

DOI

10.1038/s41467-021-25937-1

PubMed

34552098

Mer information

Senast uppdaterat

2021-10-05