纤锌矿GaN/AlN量子阱中的极化子

Polarons in a Wurtzite GaN/AlN Quantum Well

采用Lee-Low-Pines(LLP)变分法,讨论了纤锌矿(闪锌矿)GaN/AlN无限深量子阱材料中电子-定域长波光学声子相互作用,给出纤锌矿量子阱中自由极化子的基态能量、第一激发态能量和跃迁能量随阱宽的变化关系.数值计算中考虑了纤锌矿材料的各向异性,结果表明,极化子能量随阱宽的增大而减小,当阱宽较宽时,趋近于体材料的三维值.纤锌矿(闪锌矿)GaN/AlN量子阱材料中,电子-定域长波光学声子相互作用对极化子能量的贡献比闪锌矿GaAs/AlAs量子阱材料中的相应值大得多.因此,讨论GaN/AlN量子阱材料中电子态问题时应考虑电子-定域声子相互作用.

The interaction between an electron and confined-Longitudinal-Optical phonons in a wurtzite（zinc-blende） GaN/AlN quantum well is studied by using the Lee-Low-Pines（LLP） variational method.The ground-state energy,first excited-state energy and the transition energy of the free polaron in wurtzite material QW are calculated as a function of well width.The effect of anisotropy of the wurtzite materials has been considered in the calculation.The results show that the polaron energy decreases with increasing the well width and finally approaches to the bulk value of GaN.The contributions of the electron-phonon interaction to the energy of polaron in a wurtzite GaN/AlN quantum well are greater than that in a GaAs/AlAs quantum well.Therefore,the contribution of electron-phonon interaction should be considered for the discussion of the election states in wurtzite GaN/AlN quantum well.