Strong potential profile fluctuations and effective localization process in InGaN/GaN multiple quantum wells grown on (10-1m) faceted surface GaN template

Journal Article · Sat Jul 01 04:00:00 EDT 2006 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2214211· OSTI ID:20879958

Haffouz, S; Tang, H; Bardwell, J A; Lefebvre, P; Bretagnon, T; Riemann, T; Christen, J ^[1]

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1. Institute for Microstructural Sciences, National Research Council Canada, 1200 Montreal Road, M-50, Ottawa K1A 0R6 (Canada)

Cathodoluminescence (CL) and time-resolved photoluminescence (TRPL) spectroscopy were used to investigate the relation between the surface morphology and emission efficiency in 10x InGaN(3 nm)/GaN(4 nm) quantum wells (QWs) deposited by plasma-assisted molecular beam epitaxy (MBE). For this study, two QWs with peak emission around 405 nm but grown on different surface morphologies have been investigated. A strong increase in the emission efficiency was observed in the QWs grown on (10-1m) faceted surface GaN template (m>2) as compared to those grown on an atomically smooth template. CL mapping and temperature-dependent PL studies revealed that the QWs grown on the faceted surface GaN epilayer exhibit much stronger in-plane indium content fluctuations and larger width PL peak in the temperature range of 8-300 K. We found that the use of (10-1m) faceted surface GaN template resulted in strong potential profile fluctuations (PPFs) inducing different localization centers at different energy levels. We found that the deeper the corresponding fluctuation of the energy level, the weaker the decrease of the PL intensity with increasing temperature, the higher the PL decay time ({tau}{sub PL}) in the whole temperature range and the slower the collapse of {tau}{sub PL}. Our results demonstrate that the use of (10-1m) faceted surface morphology GaN template is an amplifying process of the PPFs which favors a regime dominated by the recombination of localized carriers.

• OSTI ID: 20879958
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 1 Vol. 100; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CATHODOLUMINESCENCE
EFFICIENCY
ENERGY LEVELS
FLUCTUATIONS
GALLIUM NITRIDES
INDIUM
INDIUM COMPOUNDS
MOLECULAR BEAM EPITAXY
MORPHOLOGY
PHOTOLUMINESCENCE
QUANTUM WELLS
SEMICONDUCTOR MATERIALS
SURFACES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TIME RESOLUTION