Strain-induced fundamental optical transition in (In,Ga)As/GaP quantum dots
Strain-induced fundamental optical transition in (In,Ga)As/GaP quantum dots
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(In,Ga)As/GaP 量子点中应变诱导的基本光学跃迁
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
O. Durand
中科院分区：
文献类型：
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作者：
C. Robert;M. Nestoklon;K. P. D. Silva;L. Pédesseau;C. Cornet;M. Alonso;A. Goñi;P. Turban;J. Jancu;J. Even;O. Durand
通过百万原子超晶胞紧束缚模拟，彻底研究了 (In,Ga)As/GaP 量子点中的基态光学跃迁的性质。精确的量子点形态是从先前报道的扫描隧道显微镜图像中推断出来的。应变场是用价力场方法计算的，对约束势有很大影响，主要是对导带态。事实上，基电子态的波函数在空间上被限制在GaP矩阵中，靠近点顶点，在大的拉伸应变区域中，主要具有Xz特征。静水压力下的光致发光实验有力地支持了理论结论。
The nature of the ground optical transition in an (In,Ga)As/GaP quantum dot is thoroughly investigated through a million atoms supercell tight-binding simulation. Precise quantum dot morphology is deduced from previously reported scanning-tunneling-microscopy images. The strain field is calculated with the valence force field method and has a strong influence on the confinement potentials, principally, for the conduction band states. Indeed, the wavefunction of the ground electron state is spatially confined in the GaP matrix, close to the dot apex, in a large tensile strain region, having mainly Xz character. Photoluminescence experiments under hydrostatic pressure strongly support the theoretical conclusions.