Infrared Physics & Technology ( IF 3.3 ) Pub Date : 2021-02-25 , DOI: 10.1016/j.infrared.2021.103695 Chuan-Zhen Zhao , Xue-Lian Qi , Tong Wei , Sha-Sha Wang , Jun Wang
A model estimating the band gap energy of the As-rich InxGa1-xBiyAs1-y is set up. An excellent description is shown. It is found that the In and Bi fractions do not modify the Г valence band maximum (VBM) independently. However, they modify the Г conduction band minimum (CBM) independently. The incorporation of the In fraction in the GaBiyAs1-y alloy will lead to the coupling interaction between the Bi level and the Г CBM of the host material decreasing. It is due to that the energy difference between the Bi level and the Г VBM of InxGa1-xAs enlarges with increasing In fraction. InxGa1-xBiyAs1-y needs less Bi fraction than GaBiyAs1-y when the spin–orbit splitting energy surpasses the band gap energy. The reason is that incorporating In fraction in GaBiyAs1-y can reduce the band gap energy while the spin–orbit splitting energy almost keeps a constant. In addition, the impurity-host interaction depends on not only the impurity anion fraction, but also the host anion fraction when the impurity anion fraction reaches a certain degree. If there are two or more cations in the alloy, the coupling parameter depending on the cation fraction should be taken into consideration. Based on the existing evidence, it can be concluded that InxGa1-xBiyAs1-y has a direct band gap in the whole composition range.
中文翻译:
富As的In x Ga 1-x Bi y As 1-y的带隙能量取决于组成
建立估计富As In x Ga 1-x Bi y As 1-y的带隙能量的模型。显示了一个很好的描述。发现In和Bi分数不会独立地改变价带最大值(VBM)。但是,它们独立地修改了Г导带最小值(CBM)。GaBi y As 1-y合金中In组分的掺入将导致Bi能级与主体材料的ГCBM之间的偶联相互作用降低。这是由于In x Ga 1-x As的Bi能级与ГVBM之间的能量差随In分数的增加而增大。在x Ga 1-x当自旋轨道分裂能超过带隙能时,Bi y As 1-y所需的Bi分数比GaBi y As 1-y少。原因是在GaBi y As 1-y中掺入In分数可以减小带隙能量,而自旋轨道分裂能量几乎保持恒定。另外,当杂质阴离子分数达到一定程度时,杂质-主体相互作用不仅取决于杂质阴离子分数,还取决于主体阴离子分数。如果合金中有两个或多个阳离子,则应考虑取决于阳离子分数的偶联参数。根据现有证据,可以得出In x Ga1-x Bi y As 1-y在整个组成范围内都有直接的带隙。