Defects in AlSb: A density functional study

Abstract

We carry out density functional calculations to study both intrinsic and extrinsic defects in AlSb. We focus on the carrier compensation and trapping properties of these defects, which are important to the radiation detection applications. We show that the Sb antisite ͑Sb Al ͒ is a low-energy defect, with interesting property of light-induced metastability, similar to the As antisite in GaAs. Sb Al is effective in compensating holes induced by the residual carbon but is also a deep electron trap that reduces the carrier drifting length. We discuss the possibility of using hydrogenated isovalent N impurity in AlSb and GaAs to pin the Fermi level without causing efficient carrier trapping.

Native point defect energetics in GaSb: Enablingp-type conductivity of undoped GaSb

“…Similar results were also found for Sb Al antisite in AlSb in Ref. 12, were charge states from + 2 to −1 were found to be stable. We also performed LDA calculations for the Sb Ga antisite, with the same system settings (system size and energy correction term) as with the HSE06 functional.…”

“…10 and 11) but very interestingly also in AlSb (Ref. 12). The prediction of the Sb Ga donor levels associated with low defect formation energies is a challenge for explaining the Even though our main focus is on the native point defects, we also perform a very limited study of extrinsic point defects, namely carbon at the substitutional Sb site and oxygen at the interstitial cation site as possible sources of p-type conductivity.…”

Recoverable degradation in InAs/AlSb high-electron mobility transistors: The role of hot carriers and metastable defects in AlSb

“…Its ground state has T d symmetry, and Du has discovered a metastable configuration with C 3V symmetry. 10 The formation energies of Sb Al ͑T d ͒ and Sb Al ͑C 3V ͒ obtained using the HSE06 hybrid functional are shown in Fig. 7.…”

“…Previous DFT calculations [8][9][10] have shown that at the lower part of the band gap, the intrinsic defects that have low formation energies are the aluminum interstitial ͑Al i ͒ and the antimony antisite ͑Sb Al ͒. We first look at Al i .…”

“…3 for these devices. We examine a range of candidate defects, using available results in the literature, [8][9][10] where available, and new calculations. For each candidate defect, we explore various configurations and calculate the formation energies of all charge states for each stable configuration.…”