Well-width dependence of the quantum efficiencies of GaN/Al{sub x}Ga{sub 1-x}N multiple quantum wells

Journal Article · Mon May 22 04:00:00 EDT 2000 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.126572· OSTI ID:20216496

Zeng, K C ^[1]; Li, J ^[1]; Lin, J Y ^[1]; Jiang, H X ^[1]

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1. Department of Physics, Kansas State University, Manhattan, Kansas 66506-2601 (United States)

A set of GaN/Al{sub x}Ga{sub 1-x}N(x{approx_equal}0.2) multiple quantum wells (MQWs) with well widths, L{sub w}, varying from 6 to 48 Aa has been grown by metalorganic chemical vapor deposition under the optimal GaN-like growth conditions. Picosecond time-resolved photoluminescence spectroscopy has been employed to probe the well-width dependence of the quantum efficiencies (QE) of these MQWs. Our results have shown that these GaN/AlGaN MQW structures exhibit negligibly small piezoelectric effects and hence enhanced QE. Furthermore, GaN/Al{sub x}Ga{sub 1-x}N MQWs with L{sub w} between 12 and 42 Aa were observed to provide the highest QE, which can be attributed to the reduced nonradiative recombination rate as well as the improved quantum-well quality. The decreased QE in GaN/Al{sub x}Ga{sub 1-x}N MQWs with L{sub w}<12 Aa is due to the enhanced carrier leakage to the underlying GaN epilayers, while the decreased QE in MQWs with L{sub w}>42 Aa is associated with an increased nonradiative recombination rate as L{sub w} approaching the critical thickness of MQWs. The implications of our results on device applications are also discussed. (c) 2000 American Institute of Physics.

• OSTI ID: 20216496
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 21 Vol. 76; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM NITRIDES
CHEMICAL VAPOR DEPOSITION
EXPERIMENTAL DATA
GALLIUM NITRIDES
HETEROJUNCTIONS
PHOTOLUMINESCENCE
PIEZOELECTRICITY
QUANTUM EFFICIENCY
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