纤锌矿结构的GaAlN/GaN量子阱中电子激发态极化的压力效应

摘要

研究了GaN/GaAlN量子阱内电子的激发态极化(EESP)的压力效应,计算中考虑了纤锌矿结构材料的晶格常数、形变势的各向异性,以及内建电场(IEF)的作用.结果表明: 电子势垒高度随压力下降;电子基态有效质量随压力下降而电子的第一激发态有效质量随压力上升; EESP强度随压力缓慢上升;电子极化的偶极矩随Al浓度非线性下降.一般情况下,EESP对IEF的影响可忽略,但当掺杂浓度n足够大(n》1019/cm3)时,EESP可屏蔽IEF.%The pressure effects on the electronic excited-state polarization (EESP) in the GaN/GaAlN quantum wells were studied.In calculation,anisotropy of the lattice constants and the deformation potentials of the wurtzite structure and the build-in internal electric field (IEF) as well are considered.It was shown that the electronic barrier height decreases with pressure,the ground state electronic effective mass decreases while the first excited-state electronic effective mass increases under pressure,and the strength of the EESP increases slowly with pressure;the dipole moments decrease with Al content non-linearly.Generally,the influence of the EESP on the IEF can be neglected but the EESP field may screen the build-in IEF when the density of the doped electron n is big enough (e.g.,n is above 1019/cm3).