Native point defects in antiperovskite Ba₃SbN: a promising semiconductor for photovoltaics

We present a theoretical investigation on intrinsic defects of hexagonal antiperovskite Ba₃SbN, 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 Ba₃SbN. 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, Ba₃SbN 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 Ba₃SbN 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.