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arXiv · 1208.1246

Engineering direct-indirect band gap transition in wurtzite GaAs nanowires through size and uniaxial strain

Andrew Copple·Nathaniel Ralston·Xihong Peng
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Abstract

Electronic structures of wurtzite GaAs nanowires in the [0001] direction were studied using first-principles calculations. It was found that the band gap of GaAs nanowires experience a direct-to-indirect transition when the diameter of the nanowires is smaller than ~28 {\AA}. For those thin GaAs nanowires with an indirect band gap, it was found that the gap can be tuned to be direct if a moderate external uniaxial strain is applied. Both tensile and compressive strain can trigger the indirect-to-direct gap transition. The critical strains for the gap-transition are determined by the energy crossover of two states in conduction bands.

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Andrew Copple, Nathaniel Ralston, Xihong Peng. 2012-08-06. Engineering direct-indirect band gap transition in wurtzite GaAs nanowires through size and uniaxial strain. https://doi.org/10.1063/1.4718026

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