Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7839731 | Journal of Luminescence | 2018 | 7 Pages |
Abstract
Carrier dynamics including carrier relaxation and tunneling within a coupled InAs quantum dot (QD) - In0.15Ga0.85As quantum well (QW) hybrid nanostructure are investigated using photoluminescence (PL) spectroscopy. This coupled hybrid nanostructure shows a single PL peak from the QD emission at low excitation intensity and a band filling behavior is observed as the excitation intensity increases, suggesting that there exists a channel to capture carriers from the QW to the QDs. Time resolved PL (TRPL) measurements extract a carrier tunneling time of 103.7â¯ps, which is only one third of the theoretical prediction. A double-channel resonant carrier tunneling mechanism from the QW to the wetting layer and to the fifth excited state of the QDs and then carrier relaxation into lower discrete QD energy states is proposed to explain this fast carrier tunneling. The double-channel resonant carrier tunneling mechanism is qualitatively supported through the analysis of the excitation-dependent PL spectra as well as the PL excitation spectra. These results enrich our understanding of carrier dynamics in coupled QD and QW hybrid structures.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Ying Wang, Xinzhi Sheng, Qing Yuan, Qinglin Guo, Shufang Wang, Guangsheng Fu, Baolai Liang, Diana L. Huffaker, Yuriy I. Mazur, Yurii Maidaniuk, Morgan E. Ware, Gregory J. Salamo,