Liang, Baolai, Huffaker, Diana, Mazur, Yuriy, Ware, Morgan, Salamo, Gregory, Yuan, Qing, Wang, Ying, Li, Xiaoli, Wang, Shufang and Fu, Guangsheng
2019.
Type-II GaSb/InAlAs quantum dots grown on InP (001) substrate by droplet epitaxy (Conference Presentation).
Presented at: SPIE OPTO,
San Francisco, CA, USA,
2-7 February 2019.
Published in: Huffaker, Diana L. ed.
Proceedings Volume 10929, Quantum Dots and Nanostructures: Growth, Characterization, and Modeling XVI.
Society of Photo-Optical Instrumentation Engineers (SPIE),
109290H.
10.1117/12.2509207
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Abstract
The GaSb quantum dots (QDs) with type II band alignment have attracted great attention recently. They are predicted to be optimizing active region materials for achieving high efficient intermediate-band solar cells and for obtaining ultra-long storage time for memory cells. In this research, GaSb QDs sandwiched inside InAlAs matrix lattice-matched to InP (001) substrate have been obtained via droplet epitaxy. The droplet epitaxy enable us to achieve low density (~2.6 x 10^9/cm^2) and large size (average height ~6.5nm) for the QDs while the lattice mismatch between the GaSb and InAlAs matrix is only ~4%. PL measurements reveal a type-II band alignment for these GaSb/InAlAs/InP QDs. The PL peak energy of QDs shows a blue-shift of >100 meV when the laser intensity increases by six orders of magnitude. Time-resolved PL measurements further confirm the type-II band alignment for the QDs by showing a maximum carrier lifetime of ~4.5 ns. The abnormal dependence of peak energy of QD PL band on the temperature in together with the special PL decay curve indicate that these GaSb/InAlAs QDs likely have different physics mechanism from common GaSb/GaAs type-II QDs. This study provide useful information for understanding the band structure and carrier dynamics of the GaSb/InAlAs QDs grown on InP surface.
Item Type: |
Conference or Workshop Item
(Paper)
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Date Type: |
Published Online |
Status: |
Published |
Schools: |
Physics and Astronomy |
Publisher: |
Society of Photo-Optical Instrumentation Engineers (SPIE) |
Date of First Compliant Deposit: |
22 March 2019 |
Date of Acceptance: |
4 March 2019 |
Last Modified: |
25 Mar 2019 11:15 |
URI: |
http://orca.cf.ac.uk/id/eprint/121079 |
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