纤锌矿GaN/ZnO量子阱中的界面声子

Interface-Optical-Phonon Modes in Wurtzite GaN/ZnO Quantum Wells

根据介电连续模型和单轴晶体模型,运用传递矩阵的方法研究了纤锌矿量子阱中的界面声子,并且计算和讨论了纤锌矿GaN/ZnO单量子阱和耦合量子阱中的界面声子的色散关系。计算结果表明纤锌矿晶体的各向异性对界面声子模有大的影响:界面声子模出现在两个能量区域中,分别是:[ω⊥,TZnO,ωz,TGaN]和[ω⊥,LZnO,ωz,LGaN];界面声子随波数q⊥的减小色散越发明显、随波数q⊥增大分别趋近于54.32meV和86.56meV两个定值;当波数q⊥值非常小时,出现界面声子的色散消失现象,消失部分将穿越界面声子的能量区域转化为准受限声子或半空间声子。

Based on the dielectric continuum model and Loudon＇s uniaxial crystal model, the interface-optical-phonon （IOP） modes in wurtzite multilayer heterostructures were investigated by using the transfer matrix method. The dispersions of the IOP in wurtzite GaN/ZnO symmetric single quantum well and coupled quantum wells were calculated and discussed. The results indicated that the anisotropic effects of wurtzite crystal have a large influence on the behaviors of IOP modes. It was found that the IOP modes exist in frequency ranges [ω⊥.TZnO,ωz,TGaN] and [ω⊥.LZnO,ωz,LGaN].The IOP modes with small wave number q ⊥ have strong dispersions, and that with large wave number q⊥ converge to the two definite limiting values 54.32 meV and 86.56 meV, respectively. For very small value of q⊥, appearance of disappearing dispersion of the IOP mode, the IOP mode transforms to the quasiconfined mode or the halfspace mode after going beyond the IOP frequency ranges.