Effective scheme to determine accurate defect formation energies and charge transition levels of point defects in semiconductors.

We propose an effective method to accurately determine the defect formation energy Ef and charge transition level ε of the point defects using exclusively cohesive energy Ecoh and the fundamental band gap Eg of pristine host materials. We find that Ef of the point defects can be effectively separated into geometric and electronic contributions with a functional form: Ef = χ Ecoh + λ Eg, where χ and λ are dictated by the geometric and electronic factors of the point defects (χ and λ are defect dependent). Such a linear combination of Ecoh and E g reproduces Ef with an accuracy better than 5% for electronic structure methods ranging from hybrid density-functional theory (DFT) to many-body random-phase approximation (RPA) and experiments. Accordingly, ε is also determined by Ecoh / Eg and the defect geometric/electronic factors. The identified correlation is rather general for monovacancies and interstitials, which holds in a wide variety of semiconductors covering Si, Ge, phosphorenes, ZnO, GaAs, and InP, and enables one to obtain reliable values of Ef and ε of the point defects for RPA and experiments based on semilocal DFT calculations. [ABSTRACT FROM AUTHOR]