Quantum Optoelectronics: publications

Dependence of carrier localization in InGaN/GaN multiple-quantum wells on well thickness

APPLIED PHYSICS LETTERS 89:25 (2006) ARTN 253120

Authors:

Jong H Na, Robert A Taylor, Kwan H Lee, Tao Wang, Abbes Tahraoui, Peter Parbrook, A Mark Fox, Sam N Yi, Young S Park, Jae W Choi, Jung S Lee

Direct optical excitation of a fullerene-incarcerated metal ion

CHEMICAL PHYSICS LETTERS 428:4-6 (2006) 303-306

Authors:

Mark AG Jones, RA Taylor, A Ardavan, K Porfyrakis, GAD Briggs

Dynamics of localized carriers in InGaN multi-quantum wells

JOURNAL OF THE KOREAN PHYSICAL SOCIETY 49:2 (2006) 538-541

Authors:

K Kyhm, RA Taylor

Enhancement of free-carrier screening due to tunneling in coupled asymmetric GaN/AlGaN quantum discs

APPLIED PHYSICS LETTERS 89:2 (2006) ARTN 023103

Authors:

Kwan H Lee, Jong H Na, Robert A Taylor, Sam N Yi, Stefan Birner, Young S Park, Chang M Park, Tae W Kang

Free carrier screening in coupled asymmetric GaN quantum discs

P SOC PHOTO-OPT INS 6352 (2006) U288-U296

Authors:

KH Lee, JH Na, S Birner, RA Taylor, SN Yi, YS Park, CM Park, TW Kang

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, 91̽��ed 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.

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