Density Functional Theory Study of the Optical and Electronic Properties of With-Defect Semiconductors using a Tuned Screened Range-Separated Hybrid

Tuned and screened range-separated hybrid (SRSH) methods have emerged as an alternative to state of the art many-body perturbation theory (MBPT) calculations of the optoelectronic properties of materials. Specifically, it has been shown that SRSH hybrid methods can approach the quantitative accuracy of MBPT at the cost of hybrid DFT for a variety of dissimilar molecules and both bulk and monolayer crystals. Here, we test the accuracy of the time-dependent (TD) SRSH approach for describing the optoelectronic properties of defective semiconductors by the study of point defects in bulk GaN. We first show that the predicted quasiparticle gap and low-energy excitation spectra of (TD)-SRSH and GW/BSE agree well in both pristine GaN and GaN with a single nitrogen vacancy, establishing the accuracy of the method. Aided by the reduced computational cost of (TD-)SRSH, we then report on a series of technologically relevant point defects and complexes in GaN. This study indicates that TD-SRSH is a promising and computationally feasible approach for quantitatively accurate, first-principles modeling of defective semiconductors.