Paper
6 October 2006 Free carrier screening in coupled asymmetric GaN quantum discs
K. H. Lee, J. H. Na, S. Birner, R. A. Taylor, S. N. Yi, Y. S. Park, C. M. Park, T. W. Kang
Author Affiliations +
Proceedings Volume 6352, Optoelectronic Materials and Devices; 635214 (2006) https://doi.org/10.1117/12.689176
Event: Asia-Pacific Optical Communications, 2006, Gwangju, South Korea
Abstract
We present an investigation of free-carrier screening in coupled asymmetric GaN quantum discs with embedded AlGaN barriers using time-integrated and time-resolved micro-photoluminescence measurements, supported by three-dimensional multi-band k.p computational modeling. We observe that with increasing optical excitation the carrier lifetime decreases and emission energy blue-shifts. This originates from the screening of built-in piezo- and pyroelectric fields in the quantum discs by photo-generated free-carriers. Due to non-resonant tunneling of carriers from the smaller disc to the larger disc, free carrier screening is enhanced in the larger disc. The non-resonant tunneling was found to have a significant role in samples with a thin barrier, as the screening decreased with barrier thickness (i.e. decreased tunneling). Computational modeling was in good agreement with the experimental results.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
K. H. Lee, J. H. Na, S. Birner, R. A. Taylor, S. N. Yi, Y. S. Park, C. M. Park, and T. W. Kang "Free carrier screening in coupled asymmetric GaN quantum discs", Proc. SPIE 6352, Optoelectronic Materials and Devices, 635214 (6 October 2006); https://doi.org/10.1117/12.689176
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KEYWORDS
Gallium nitride

Picosecond phenomena

Electrons

Computational modeling

Aluminum

Quantum wells

Optoelectronic devices

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