Te掺杂单层MoS<sub>2</sub>的电子结构与光电性质

采用基于密度泛函理论的第一性原理计算, 研究了Te掺杂对单层MoS2能带结构、电子态密度和光电性质的影响。结果表明, 本征单层MoS2属于直接带隙半导体材料, 其禁带宽度为1.64 eV。本征单层MoS2的价带顶主要由S-3p态电子和Mo-4d态电子构成, 而其导带底则主要由Mo-4d态电子和S-3p态电子共同决定; Te掺杂单层MoS2为间接带隙半导体材料, 其禁带宽度为1.47 eV。同时通过Te掺杂, 使单层MoS2的静态介电常数增大, 禁带宽度变窄, 吸收光谱产生红移, 研究结果为单层MoS2在光电器件方面的应用提供了理论基础。

Abstract

We have performed first-principles calculations based the framework of density-functional theory to determine the effects of Te doping on the band structure, density of state and photoelectric properties of single-layer MoS2. The calculated results indicate that the direct band-gap of pure single-layer MoS2 is 1.64 eV. The top of valence band is fundamentally determined by the S-3p and Mo-4d states, and the bottom of conduction band is occupied by the Mo-4d and S-3p states in the pure single-layer MoS2. Meanwhile, the indirect band-gap of Te-doped single-layer MoS2 is 1.47 eV, while the band gap of Te-doped single-layer MoS2 has decreased and the optical absorption has shown a red-shifted observably as compared with the pure single-layer MoS2, which provides important theoretical guidance for the applications of single-layer MoS2 in optical detectors.

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张昌华, 余志强, 廖红华. Te掺杂单层MoS₂的电子结构与光电性质[J]. 发光学报, 2014, 35(7): 785. ZHANG Chang-hua, YU Zhi-qiang, LIAO Hong-hua. Electronic Structure and Photoelectric Properties of Te-doped Single-layer MoS₂[J]. Chinese Journal of Luminescence, 2014, 35(7): 785.

Te掺杂单层MoS₂的电子结构与光电性质

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