Temperature-Dependent Optical Properties of InAs/GaAs Self-Assembled Quantum Dots: Spectroscopic Measurements and an Eight-Band Study
Temperature-Dependent Optical Properties of InAs/GaAs Self-Assembled Quantum Dots: Spectroscopic Measurements and an Eight-Band Study
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DOI：
10.1088/0256-307x/28/11/117301
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发表时间：
2011-11
影响因子：
3.5
通讯作者：
X. Zhou 周;Ping-Ping 平平 Chen 陈-Ping;X. Chen 陈;W. Lu 陆
中科院分区：
文献类型：
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作者：
X. Zhou 周;Ping-Ping 平平 Chen 陈-Ping;X. Chen 陈;W. Lu 陆
通过光谱测量和理论计算，研究了InAs/GaAs自组装量子点随温度变化的光学性质。我们观察到随着温度的升高，光致发光峰值能量红移和各态的热激活猝灭，这是由于量子点中载流子的有效再分配所致。同时，考虑应变效应，采用八波段k·p模型对InAs/GaAs量子点的电子结构进行了详细的理论研究。计算得到的激子跃迁能与光致发光光谱的结果基本一致。根据载流子的空间分布，发现量子点中光生激子随温度的演化主要依赖于电子而不是空穴。
The temperature-dependent optical properties of InAs/GaAs self-assembled quantum dots are studied by spectroscopic measurements along with the corresponding theoretical calculations. We observe the redshift of photoluminescence peak energy with increasing temperature and the thermally activated quenching of each state, which result from the efficient redistribution of carriers in quantum dots. Meanwhile, the electronic structures of the InAs/GaAs quantum dots are investigated by a detailed theoretical study in terms of an eight-band k·p model, taking strain effects into account. The calculated transition energies of the excitons are in reasonable agreement with the results of the photoluminescence spectra. According to the spatial distribution of carriers, it is found that the evolution of photogenerated excitons in quantum dots with temperature mainly relies on the electrons rather than the holes.