Complementary Employment of Shell DFT-1/2 and HSE06 for Defect State Calculations in InP.

Defect calculations for semiconductors demand both large supercells and accurate electronic structures, posing a significant challenge to first-principles methods. Conventional density functional theory (DFT) with local or semi-local exchange-correlation functionals severely underestimates the band gap, whereas hybrid functionals such as HSE06 provide higher accuracy but at a substantially increased computational cost. In this work, we demonstrate that shell DFT-1/2, a self-energy correction method for electronic structure calculations, may be used jointly with HSE06 to reach the optimal efficiency as well as accuracy. In particular, indium phosphide (InP) was taken as an example. The shell DFT-1/2 method was utilized to yield accurate band structures with a 1.44 eV direct gap, without any empirical parameter. Subsequently, the portion of exact exchange was tuned to match the shell DFT-1/2 electronic structure in HSE06 calculations. The charge transition levels of various point defects in InP were derived using HSE06, and HSE06 and shell DFT-1/2 may be employed alternatively to yield the density of states for the defective supercells. Their consistency proves the feasibility of the complementary employment of the two methods, and this strategy is readily extendable to other semiconductor research.