Binding Energies of Screened Excitons in a Strained(111)-Oriented Zinc-Blende GaN/AlGaN Quantum Well Under Hydrostatic Pressure  

流体静压力下应变闪锌矿(111)取向GaN/AlGaN量子阱中受屏蔽激子的结合能(英文)

作　　者：哈斯花[1] 班士良[1] 

机构地区：[1]内蒙古大学理工学院物理系,呼和浩特010021

出　　处：《Journal of Semiconductors》2008年第2期234-239,共6页半导体学报（英文版）

基　　金：国家自然科学基金(批准号:60566002);内蒙古自治区优秀学科带头人计划资助项目~~

摘　　要：We investigate the binding energies of excitons in a strained （111）-oriented zinc-blende GaN/Al0.3 Ga0.7 N quantum well screened by the electron-hole （e-h） gas under hydrostatic pressure by combining a variational method and a selfconsistent procedure. A built-in electric field produced by the strain-induced piezoelectric polarization is considered in our calculations. The result indicates that the binding energies of excitons increase nearly linearly with pressure,even though the modification of strain with hydrostatic pressure is considered, and the influence of pressure is more apparent under higher e-h densities. It is also found that as the density of an e-h gas increases,the binding energies first increase slowly to a maximum and then decrease rapidly when the e-h density is larger than about 1 ×10^11 cm^-2. The excitonic binding energies increase obviously as the barrier thickness decreases due to the decrease of the built-in electric field.结合变分法与自洽计算方法研究了流体静压力下应变闪锌矿(111)取向GaN/AlxGa1 -xN量子阱中受电子-空穴气体屏蔽的激子结合能.计算中,考虑了沿(111)取向生长多层结构时存在压电极化引起的内建电场.计算结果表明,考虑压力对双轴及单轴应变的调制以及禁带宽度、有效质量和介电常数等参数的压力效应时,激子结合能随压力的增大近似线性增加;且当电子-空穴气体密度大时,这一效应更加显著.当给定压力时,随着电子-空穴气面密度的增加,激子结合能先缓慢增加,但当密度达到大约1011cm-2时结合能开始迅速衰减.此外,当减小垒的厚度时,由于内建电场减弱,激子结合能显著增加.

关 键 词：EXCITON strained zinc-blende quantum well pressure screened effect 

分 类 号：O471[理学—半导体物理]