Intrinsic point defects in aluminum antimonide

TL;DR

This study uses advanced computational methods to analyze intrinsic point defects in aluminum antimonide, revealing defect types, their properties, and the material's conductivity behavior.

Contribution

It provides a detailed first-principles analysis of defect properties and charge carrier concentrations in aluminum antimonide, incorporating corrections for finite-size effects and band gap errors.

Findings

Key defects identified: Al interstitial, Sb antisites, Al vacancy.

Material is n-type conducting at finite temperatures.

Defect and charge carrier concentrations calculated self-consistently.

Abstract

Calculations within density functional theory on the basis of the local density approximation are carried out to study the properties of intrinsic point defects in aluminum antimonide. Special care is taken to address finite-size effects, band gap error, and symmetry reduction in the defect structures. The correction of the band gap is based on a set of GW calculations. The most important defects are identified to be the aluminum interstitial $Al_{i,Al}^{1+}$, the antimony antisites $Sb_{Al}^0$ and $Sb_{Al}^{1+}$, and the aluminum vacancy $V_{Al}^{3-}$. The intrinsic defect and charge carrier concentrations in the impurity-free material are calculated by self-consistently solving the charge neutrality equation. The impurity-free material is found to be n-type conducting at finite temperatures.