双轴应变对单层CdZnTe电子特性和光学性能的影响

摘要/Abstract

摘要： 研究双轴应变对单层CdZnTe半导体材料电子特性与光学性能的影响,可为制备光学性能优异的CdZnTe器件提供理论支持。本文采用Material Studio 软件构建单层CdZnTe模型,并在其(100)和(010)方向上施加应变。基于密度泛函理论的第一性原理模拟计算了单层双轴应变对单层CdZnTe带隙、载流子有效质量、迁移率和介电常数等性能的影响。结果表明,拉伸和压缩应变均能减小单层CdZnTe的带隙,且双轴应变可有效调控单层CdZnTe的载流子有效质量、迁移率和介电常数。与拉伸应变相比,相同大小的压缩应变对单层CdZnTe性能的调控更加明显。随施加双轴压缩应变的增大,单层CdZnTe的带隙值逐渐减小,CdZnTe半导体吸收光的波长范围得到提高,单层CdZnTe的载流子有效质量、迁移率总体呈下降趋势,介电常数实部逐渐下降,虚部逐渐上升,意味着单层CdZnTe的金属性增强,光学性能提高。

关键词: CdZnTe, 第一性原理, 带隙, 双轴应变, 载流子有效质量, 介电常数

Abstract: Studying the effect of biaxial strain on the electronic and optical properties of single-layer CdZnTe semiconductor materials provide theoretical support for the preparation of CdZnTe devices with excellent optical properties. In this paper, a single-layer CdZnTe model was built with the Material Studio software, and strain is applied to the model in the (100) and (010) directions. Based on the first-principle of density functional theory, the effects of biaxial strain on the band gap, effective mass of carrier, mobility and dielectric constant of single-layer CdZnTe were simulated and calculated. The results show that both tensile and compressive strains reduce the band gap of the single-layer CdZnTe, and biaxial strain effectively control the effective mass, mobility and dielectric constant of carriers. Compared with the tensile strain, compression strain of the same size has more obvious effect on the properties of the single-layer CdZnTe. With the increase of applied biaxial compression strain, the band gap of the single-layer CdZnTe gradually decreases, which leds to the increase of wavelength range of absorption light of the CdZnTe semiconductor, and the carrier effective mass and mobility of single-layer CdZnTe show an overall downward trend. Also, the increase of applied biaxial compression strain makes the real part of the dielectric constant gradually decrease and the imaginary part of the dielectric constant gradually increase, which enhances the metallicity of the single layer CdZnTe and improves its optical performance.

Key words: CdZnTe, first-principle, band gap, biaxial strain, effective mass of carrier, dielectric constant

中图分类号:

TN304.2

聂凡, 韩硕, 曾冬梅. 双轴应变对单层CdZnTe电子特性和光学性能的影响[J]. 人工晶体学报, 2023, 52(8): 1394-1399.

NIE Fan, HAN Shuo, ZENG Dongmei. Effect of Biaxial Strain on Electronic and Optical Properties of Single-Layer CdZnTe[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2023, 52(8): 1394-1399.

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