InAs/In_x Ga_(1-x)Sb二类超晶格红外探测器的吸收波长与电子-空穴波函数交叠的研究  

On detection wavelength and electron-hole wave function overlap of type Ⅱ InAs/In_x Ga_(1-x)Sb superlattice infrared photodetector

作　　者：黄建亮[1] 卫炀[1] 马文全[1] 杨涛[1] 陈良惠[1] 

机构地区：[1]中科院半导体研究所纳米光电实验室,北京100083

出　　处：《物理学报》2010年第5期3099-3106,共8页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(973项目)(批准号:2010CB327602)资助的课题~~

摘　　要：运用包络函数模型和传输矩阵方法计算了二类超晶格的能级结构.考虑到InAs与InxGa1-xSb结合存在应变,在计算中InAs/InxGa1-xSb二类超晶格的带阶采用模型固体理论处理.因为吸收系数与电子-空穴波函数交叠成正比,所以研究了InAs/InxGa1-xSb二类超晶格红外探测器的吸收波长和电子-空穴波函数交叠与InAs层厚度,InxGa1-xSb层厚度,In组分之间和周期数的关系.结果表明,吸收波长随InAs层厚度的增大而增大,随InxGa1-xSb层厚度增大而增大,随In组分增加而增大,随周期数的增大,先减小后不变.而电子-空穴波函数的交叠随InAs层厚度的增大而减小,随InxGa1-xSb层厚度增大也减小,随In组分增加而稍微增大,随周期数的增大,先增大后缓慢增加,然后基本上保持不变.另外,发现在相同的吸收波长下,InAs层的厚度与InxGa1-xSb层的厚度的比值越大,波函数的交叠也越大.In this paper,the detection wavelength and the electron-hole wave function overlap of InAs/InxGa1-x Sb type Ⅱ superlattice photodetectors are numerically calculated by using the envelope function and the transfer matrix methods. The band offset is dealt with by employing the model solid theory,which already takes into account the lattice mismatch between InAs and InxGa1-xSb layers. Firstly,the detection wavelength and the wave function overlap are investigated in dependence on the InAs and InxGa1 -xSb layer thicknesses,the In mole fraction,and the periodic number. The results indicate that the detection wavelength increases with increasing In mole fraction,InAs and InxGa1-xSb layer thicknesses,respectively. When increasing the periodic number,the detection wavelength first increases distinctly for small periodic numbers then increases very slightly for large period numbers. Secondly,the wave function overlap diminishes with increasing InAs and InxGa1-xSb layer thicknesses,while it enhances with increasing In mole fraction. The dependence of the wave function overlap on the periodic number shows the same trend as that of the detection wavelength on the periodic number. Moreover,for a constant detection wavelength,the wave function overlap becomes greater when the thickness ratio of the InAs over InxGa1-xSb is larger.

关 键 词：二类超晶格 红外探测器 波函数的交叠 传输矩阵 

分 类 号：TN215[电子电信—物理电子学]