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arXiv · 1207.0103

First-principles study of native point defects in Bi2Se3

L. Xue·P. Zhou·C. X. Zhang·C. Y. He·G. L. Hao·L. Z. Sun·J. X. Zhong
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Abstract

Using first-principles method within the framework of the density functional theory, we study the influence of native point defect on the structural and electronic properties of Bi$_2$Se$_3$. Se vacancy in Bi$_2$Se$_3$ is a double donor, and Bi vacancy is a triple acceptor. Se antisite (Se$_{Bi}$) is always an active donor in the system because its donor level ($\varepsilon$(+1/0)) enters into the conduction band. Interestingly, Bi antisite(Bi$_{Se1}$) in Bi$_2$Se$_3$ is an amphoteric dopant, acting as a donor when $μ$$_e$$<$0.119eV (the material is typical p-type) and as an acceptor when $μ$$_e$$>$0.251eV (the material is typical n-type). The formation energies under different growth environments (such as Bi-rich or Se-rich) indicate that under Se-rich condition, Se$_{Bi}$ is the most stable native defect independent of electron chemical potential $μ$$_e$. Under Bi-rich condition, Se vacancy is the most stable native defect except for under the growth window as $μ$$_e$$>$0.262eV (the material is typical n-type) and $Δ$$μ$$_{Se}$$<$-0.459eV(Bi-rich), under such growth windows one negative charged Bi$_{Se1}$ is the most stable one.

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L. Xue, P. Zhou, C. X. Zhang, C. Y. He, G. L. Hao, L. Z. Sun, J. X. Zhong. 2012-06-30. First-principles study of native point defects in Bi2Se3. https://arxiv.org/abs/1207.0103

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