激光与光电子学进展, 2020, 57 (9): 091602, 网络出版: 2020-05-06
张应变Ge1-xSnx合金导带结构调控 下载: 750次
Calculation of Conduction Band Structure Tensile Strained Ge1-xSnx Alloys for Achieving Direct Band Gap Materials
材料 Ge1-xSnx合金 双轴张应变 单轴张应变 能带工程 materials Ge1-xSnx alloy biaxial tensile strain uniaxial tensile strain band engineering
摘要
采用形变势理论系统地研究了(001)、(110)、(111)晶面双轴张应变以及[001]、[110]、[111]晶向单轴张应变Ge1-xSnx导带结构。结果表明:在 (001)、(110)晶面施加双轴张应变以及[001]晶向施加单轴张应变时,直接带隙Γ能谷的下降速度快于间接带隙L能谷;在 (111)晶面施加双轴张应变以及[110] 、[111]晶向施加单轴张应变时,间接带隙L能谷的下降速度快于直接带隙Γ能谷。因此,可利用(001)、(110)晶面双轴张应变以及[001]晶向单轴张应变实现通过减小Sn的组分将Ge1-xSnx合金调控为直接带隙材料的目的。相关结论可为Ge1-xSnx合金的实验制备及器件仿真等提供关键参数和理论指导。
Abstract
In this study, we systematically calculate the conduction band structure of biaxial tensile strain paralleled to (001),(110), and (111) crystal planes and uniaxial tensile strain paralleled to [001], [110], and [111] crystal direction in Ge1-xSnx alloys based on the deformation potential theory. Results indicate that the descent speed in the Γ valley is faster than that in the L valley in the case of biaxial tensile strain paralleled to (001) and (110) crystal planes and uniaxial tensile strain paralleled to [001] crystal direction in Ge1-xSnx. However, the descent speed in the L valley is faster than that in the Γ valley in the case of biaxial tensile strain paralleled to (111) crystal plane and uniaxial tensile strain paralleled to [110] and [111] crystal directions in Ge1-xSnx. The strategy of tuning Ge1-xSnx alloy into a direct band gap material is proposed for reducing Sn composition based on biaxial tensile strain paralleled to (001) and (110) crystal planes and uniaxial tensile strain paralleled to [001] crystal direction in Ge1-xSnx alloy which will provide references for the experimental preparation and device simulation.
孙钦钦, 黄诗浩. 张应变Ge1-xSnx合金导带结构调控[J]. 激光与光电子学进展, 2020, 57(9): 091602. Qinqin Sun, Shihao Huang. Calculation of Conduction Band Structure Tensile Strained Ge1-xSnx Alloys for Achieving Direct Band Gap Materials[J]. Laser & Optoelectronics Progress, 2020, 57(9): 091602.