Native point defects in antiperovskite BaSbN: a promising semiconductor for photovoltaics.

We present a theoretical investigation on intrinsic defects of hexagonal antiperovskite BaSbN, a promising lead-free semiconductor for photovoltaics. Our hybrid functional calculations reveal that Ba, Sb and N vacancies, and N interstitials become major point defects in BaSbN. Conversely, other interstitials and antisites have large formation energies and their concentrations are controllable. Herein, defect levels and configuration coordinate diagrams for the major defects are analyzed, thereby revealing that defect-assisted carrier recombination is ineffective. Thus, BaSbN can be a defect-tolerant semiconductor that retains excellent optoelectronic properties despite the presence of point defects. By elucidating the stability of the intrinsic defects of BaSbN and their impacts on the carrier capture process, this work will pave the way for the development of a new class of high-performance solar cells based on antiperovskite semiconductors.