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Title: Enhanced room-temperature mid-ultraviolet emission from AlGaN/AlN Stranski-Krastanov quantum dots

We report on the identification of an optimum deposited amount of AlGaN in AlGaN/AlN quantum dot (QD) superlattices grown by molecular-beam epitaxy, which grants maximum luminescence at room temperature by finding a compromise between the designs providing maximum internal quantum efficiency (60%) and maximum QD density (9.0 × 10{sup 11 }cm{sup −2}). The average Al composition in the QDs is estimated at 10.6% ± 0.8% by combining x-ray diffraction measurements with three-dimensional calculations of the strain distribution. The effect of the variation of the QD height/base-diameter ratio on the interband and intraband optical properties was explored by fitting the experimental data with three-dimensional calculations of the band diagram and quantum confined states.
Authors:
; ; ; ;  [1] ;  [2] ; ;  [1] ;  [2]
  1. Université Grenoble Alpes, 38000 Grenoble (France)
  2. (France)
Publication Date:
OSTI Identifier:
22308714
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM NITRIDES; DISTRIBUTION; ELECTRONIC STRUCTURE; GALLIUM COMPOUNDS; LUMINESCENCE; MOLECULAR BEAM EPITAXY; OPTICAL PROPERTIES; QUANTUM DOTS; QUANTUM EFFICIENCY; STRAINS; SUPERLATTICES; TEMPERATURE RANGE 0273-0400 K; ULTRAVIOLET RADIATION; X-RAY DIFFRACTION