有强内电场的GaN-基阶梯量子阱中的线性与非线性光吸收（英文）  

Intersubband optical absorptions of a Ga N-based step quantum well with built-in electric field

作　　者：张立[1] 

机构地区：[1]广州番禺职业技术学院电子技术与材料开发研究所,广东广州511483

出　　处：《红外与毫米波学报》2015年第5期538-544,共7页Journal of Infrared and Millimeter Waves

基　　金：jointly supported by the NNSF of China(60906042 and 61178003);the Yangchen Scholar Project(10B010D);the STPAA(10B001)of Guangzhou City,STP of Panyu Region(2010-D-09-1103004);Project of Academic Innovation Group of Guangzhou City(13C17)

摘　　要：采用密度矩阵方法,考察了带强内建电场GaN-基阶梯量子阱中的线性与非线性光吸收系数.基于能量依赖的有效质量方法,在考虑了带的非抛物性情况下,推导了结构中的精确解析的电子本征态,给出了系统中简单解析的线性与非线性光吸收系数表达式.以AlN/GaN/AlxGa1-xN/AlN阶梯量子阱为例进行了数值计算.结果发现阶梯量子阱的阱宽Lw、阶梯垒宽Lb、阶梯垒的掺杂浓度x的减小将提高体系的吸收系数.而且,随着Lw,Lb和x减小,吸收光子的能量有明显的蓝移,总吸收系数的半宽度及饱和吸收强度均减小.计算获得的部分结果与最近的实验观察完全一致.By using the compact density matrix approach,the linear and nonlinear optical absorption coefficients in a GaN-based step quantum w ell（ QW） w ith strong built-in electric field（ BEF） have been theoretically deduced and investigated in detail. The band nonparabolicity is taken into account by using an energy-dependent effective mass（ EDEM） method. The exact electronic eigen-states in the step QW w ith strong BEF w ere obtained and the simple analytical formulas for the linear and nonlinear optical absorption coefficients in the systems w ere also deduced. Numerical calculations on an AlN / GaN / AlxGa1-xN / AlN step QW w ere performed. It is found that the decreasing of w ell w idth Lwand step barrier w idth Lband the doped concentration x in step barrier can result in the enhancement of the absorption coefficients. M oreover,w ith the decrease of Lw,Lband x,the photon energies of absorption have blue-shift,and the full-w idth-at-half-maximum of the total absorption coefficient increases and the saturation absorption intensity decrease. Some results are consistent w ith recent experimental observations.

关 键 词：密度矩阵方法 吸收系数 内电场 

分 类 号：O431.2[机械工程—光学工程]