Role of Sb Compositions on the Properties of InAs/GaAsSb Quantum Dots (QDs)
QD size, uniformity and density in InAs/GaAsSb material system for increasing Sb content are studied using Atomic Force Microscopy (AFM). AFM results show that QD density and uniformity improve with Sb content increase. The improvement of QD uniformity is ensured by the narrowing of the analysis of AFM scans. To obtain minimum VBO, InAs/GaAsSb with various Sb compositions is investigated by PL and TRPL measurements. PL data shows a blue-shift as excitation power increases as evidence of a type II band structure. Since the PL peak of 8 and 13 % Sb samples did not shift while that of 15 % Sb sample is blue-shifted with increasing the excitation power it is concluded that InAs QDs/GaAs0.86Sb0.14 would have minimum valence band offset. This tendency is supported by the change of a carrier lifetime estimated from TRPL data.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
- DOE Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1047347
- Report Number(s):
- NREL/CP-5200-55324; TRN: US201216%%207
- Resource Relation:
- Conference: Presented at the SPIE Conference, 23-26 January 2012, San Francisco, California; Related Information: Paper No. 82561C
- Country of Publication:
- United States
- Language:
- English
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