Stability and electronic structure of the low-Σ grain boundaries in CdTe: a density functional study

Abstract

Using first-principles density functional calculations, we investigate the relative stability and electronic structure of the grain boundaries (GBs) in zinc-blende CdTe. Among the low- Σ -value symmetric tilt Σ 3 (111), Σ 3 (112), Σ 5 (120), and Σ 5 (130) GBs, we show that the Σ 3 (111) GB is always the most stable due to the absence of dangling bonds and wrong bonds. The Σ 5 (120) GBs, however, are shown to be more stable than the Σ 3 (112) GBs, even though the former has a higher Σ value, and the latter is often used as a model system to study GB effects in zinc-blende semiconductors. Moreover, we find that although containing wrong bonds, the Σ 5 (120) GBs are electrically benign due to the short wrong bond lengths, and thus are not as harmful as the Σ 3 (112) GBs also having wrong bonds but with longer bond lengths.

Keywords

• grain bondaries
• II-VI semiconductors
• impurity and defect levels in semiconductors
• radiation effects in semiconductors
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