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Proceedings Paper

Optimizing GaN/AlGaN multiple quantum well structures by time-resolved photoluminescence
Author(s): Jing Li; Kecai Zeng; Eunjoo Shin; Jing Yu Lin; Hongxing Jiang
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Paper Abstract

We present the results of picosecond time-resolved photoluminescence (PL) measurements for GaN/AlxGa1-xN MQWs with varying structural parameters, grown by metalorganic chemical vapor deposition under the optimal GaN-like growth conditions. We have shown that the optimal GaN/AlGaN (x approximately 0.2) MQW structures for UV light emitter applications are those with well widths ranging from 12 and 42 angstroms and barrier widths ranging from 40 to 80 angstroms. The decreased quantum efficiency in GaN/AlxGa1-xN MQWs with well width LW < 12 angstroms is due to the enhanced carrier leakage to the underlying GaN epilayers, while the decreased quantum efficiency in MQWs with well width LW > 42 angstroms is associated with an increased nonradiative recombination rate as LW approaching the critical thickness of MQWs. For the barrier width dependence, when the barrier width is below the critical thickness, the nonradiative recombination rate increases with a decrease of the barrier width due to the enhanced possibilities of the electron and hole wavefunctions at the interfaces as well as in the AlGaN barriers. On the other hand, the misfit dislocation density increases as the barrier width approaches the critical thickness, which can result in an enhanced nonradiative interface recombination rate. Our optimized GaN/AlxGa1-xN MQW structures exhibited extremely high quantum efficiencies as well as a ratio of well emission intensity to barrier emission intensity exceeding 104.

Paper Details

Date Published: 23 April 2001
PDF: 8 pages
Proc. SPIE 4280, Ultrafast Phenomena in Semiconductors V, (23 April 2001); doi: 10.1117/12.424744
Show Author Affiliations
Jing Li, Kansas State Univ. (United States)
Kecai Zeng, Kansas State Univ. (United States)
Eunjoo Shin, Kansas State Univ. (United States)
Jing Yu Lin, Kansas State Univ. (United States)
Hongxing Jiang, Kansas State Univ. (United States)

Published in SPIE Proceedings Vol. 4280:
Ultrafast Phenomena in Semiconductors V
Hongxing Jiang; Kong-Thon F. Tsen; Jin-Joo Song, Editor(s)

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