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Title: Quantification of the internal quantum efficiency in GaN via analysis of the heat generated by non-radiative recombination processes

The internal quantum efficiency (IQE) in a GaN epilayer is quantified using transient lens (TL) spectroscopy and numerical simulations. TL spectroscopy can optically detect temperature and carrier changes induced in a photo-pumped GaN layer, and the observed temperature change is closely associated with non-radiative recombination processes that create heat. Then numerically solving diffusion equations, which represent the diffusion processes of the photo-generated heat and carriers, provide the spatiotemporal distributions. These distributions are subsequently converted into the refractive index distributions, which act as transient convex or concave lenses. Finally, ray-tracing simulations predict the TL signals. Comparing the experimentally obtained and simulated TL signals quantifies the generated heat and the IQE without the often-adopted assumption that non-radiative recombination processes are negligible at low temperatures.
Authors:
; ; ;  [1] ;  [2]
  1. Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510 (Japan)
  2. Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka 819-0395 (Japan)
Publication Date:
OSTI Identifier:
22399277
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION SPECTROSCOPY; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; DIFFUSION; DIFFUSION EQUATIONS; GALLIUM NITRIDES; HEAT; LAYERS; QUANTUM EFFICIENCY; RECOMBINATION; REFRACTIVE INDEX; TEMPERATURE DEPENDENCE; TRANSIENTS