Exciton acoustic-phonon coupling in single GaN/AlN quantum dots
Exciton acoustic-phonon coupling in single GaN/AlN quantum dots
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DOI：
10.1103/physrevb.85.081303
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发表时间：
2012-02-06
影响因子：
3.7
通讯作者：
Arakawa, Yasuhiko
中科院分区：
文献类型：
--
作者：
Ostapenko, Irina A.;Hoenig, Gerald;Arakawa, Yasuhiko
通过阴极荧光实验详细研究了纤锌矿型GaN/AlN单量子点中声学声子与激子的耦合，并与理论进行了比较。在基于8带k·p理论的具有实际波函数的独立玻色子模型框架内对耦合进行的数值模拟，与观测到的发射线形状显示出良好的一致性。我们分析了量子点的几何形状和内建偶极矩对声子耦合强度的光谱分布以及不同耦合机制的影响。我们通过压电耦合观察到横向声子的显著贡献。从光谱扩散的角度讨论了零声子线普遍存在的展宽。
Coupling of acoustic phonons to excitons in single wurtzite-type GaN/AlN quantum dots is investigated in detail by cathodoluminescence experiments and compared to theory. Numerical simulations of the coupling in the framework of the independent Boson model with realistic wave functions based on 8-band k . p theory show good agreement with observed emission line shapes. We analyze the influence of the geometry and the built-in dipole moment of the quantum dots on the spectral distribution of phonon-coupling strength and the different coupling mechanisms. We observe considerable contribution of the transversal phonons via piezoelectric coupling. The omnipresent broadening of the zero-phonon line is discussed in terms of spectral diffusion.