Hybrid density functional studies of intrinsic defects in Zn2SbN3 for potential solar cell application

Abstract

Zn₂SbN₃ semiconductors with defect-tolerant properties have a simple structure and promise to be useful in a variety of solar energy conversion applications. The calculated results indicate that Zn₂SbN₃ has a band gap of 1.55 eV, which corresponds to the optimal solar energy absorption band gap. In the visible light range, its absorption coefficient can reach up to 10⁴–10⁵ cm⁻¹, which makes it a suitable material for solar photovoltaic applications. Hybrid functional calculations are used to investigate electronic and defect properties. Our research indicates that Sb_Zn, Zn_i, and V_N1 are the most dominant native defects with low formation energy, which means that the experiment is associated with high resistivity. V_N1 has multiple localized defect states in the band gap that play a significant role in photovoltaic properties and can capture free carriers. This study provides a detailed theoretical explanation of the main reason for the inefficiency of nitride semiconductors as solar cell materials. Also, this is a comprehensive theoretical reference that can be used to grow high-quality thin films and other nitride semiconductor solar cells in experiments.