Ultrafast carrier capture and relaxation in modulation-doped InAs quantum dots
Ultrafast carrier capture and relaxation in modulation-doped InAs quantum dots
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DOI：
10.1063/1.2197309
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发表时间：
2006-04
影响因子：
4
通讯作者：
K. Sun;A. Kechiantz;B. C. Lee;Chien-Ping Lee
中科院分区：
文献类型：
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作者：
K. Sun;A. Kechiantz;B. C. Lee;Chien-Ping Lee
我们报告了使用时间分辨率约为 200fs 的时间分辨光谱技术对未掺杂和调制掺杂的 InAs∕GaAs 自组装量子点 (QD) 中的载流子捕获和弛豫过程进行的研究。我们发现，即使在低至 1×1010cm−2 的激发能级下，带电 QD 的基态载流子捕获和弛豫也比未掺杂的点更快。这是由于掺杂点中冷载流子的存在引起的振动偏振场的触发。带正电的量子点捕获电子的速率也是根据我们提出的模型计算的。
We report investigations on carrier capture and relaxation processes in undoped and modulation-doped InAs∕GaAs self-assembled quantum dots (QDs) by using time-resolved spectroscopy technique with a time resolution of ∼200fs. We find that carrier capture and relaxation in the ground state of the charged QD are faster compared to the undoped dots even at an excitation level as low as 1×1010cm−2. It is attributed to the triggering of the vibrating polarization field induced by the presence of cold carriers in the doped dots. The rate of an electron been captured by a positively charged QD is also calculated based on our proposed model.