Effective-mass theory for hierarchical self-assembly of GaAs/AlxGa1-xAs quantum dots -: art. no. 155301
Effective-mass theory for hierarchical self-assembly of GaAs/AlxGa1-xAs quantum dots -: art. no. 155301
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DOI：
10.1103/physrevb.71.155301
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发表时间：
2005-04-01
影响因子：
3.7
通讯作者：
Xia, JB
中科院分区：
文献类型：
--
作者：
Li, SS;Chang, K;Xia, JB
在有效质量包络函数理论的框架下，对GaAs/AlxGa 1-xAs量子点分级自组装过程中的电子结构进行了理论研究.计算了电子和空穴的能级和光学跃迁能。计算中考虑了有限偏移效应、价带混合效应、不同区域电子和空穴有效质量不同的影响以及真实的量子点结构。结果表明：随着GaAs量子点高度的增加，电子能级单调下降，能级间的能量差增大;随着GaAs量子点宽度的变化，不同能级间存在较强的态混合;随着GaAs量子点尺寸的增大，空穴能级比电子能级下降得快;（4）在激发态，空穴能级比电子能级更接近，（5）第一重空穴跃迁能和第一轻空穴跃迁能非常接近.我们的理论结果与现有的实验数据吻合得很好。我们的计算结果对GaAs/AlxGa 1-xAs量子点分级自组装在光电器件中的应用具有参考价值。
The electronic structures in the hierarchical self-assembly of GaAs/AlxGa1-xAs quantum dots are investigated theoretically in the framework of effective-mass envelope function theory. The electron and hole energy levels and optical transition energies are calculated. In our calculation, the effect of finite offset, valence-band mixing, the effects due to the different effective masses of electrons and holes in different regions, and the real quantum dot structures are all taken into account. The results show that (1) electronic energy levels decrease monotonically, and the energy difference between the energy levels increases as the GaAs quantum dot (QD) height increases; (2) strong state mixing is found between the different energy levels as the GaAs QD width changes; (3) the hole energy levels decrease more quickly than those of the electrons as the GaAs QD size increases; (4) in excited states, the hole energy levels are closer to each other than the electron ones; (5) the first heavy- and light-hole transition energies are very close. Our theoretical results agree well with the available experimental data. Our calculated results are useful for the application of the hierarchical self-assembly of GaAs/AlxGa1-xAs quantum dots to photoelectric devices.