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Title: Band gaps of wurtzite Sc{sub x}Ga{sub 1−x}N alloys

Optical transmittance measurements on epitaxial, phase-pure, wurtzite-structure Sc{sub x}Ga{sub 1−x}N films with 0 ≤ x ≤ 0.26 showed that their direct optical band gaps increased from 3.33 eV to 3.89 eV with increasing x, in agreement with theory. These films contained I{sub 1}- and I{sub 2}-type stacking faults. However, the direct optical band gaps decreased from 3.37 eV to 3.26 eV for Sc{sub x}Ga{sub 1−x}N films, which additionally contained nanoscale lamellar inclusions of the zinc-blende phase, as revealed by aberration-corrected scanning transmission electron microscopy. Therefore, we conclude that the apparent reduction in Sc{sub x}Ga{sub 1−x}N band gaps with increasing x is an artefact resulting from the presence of nanoscale zinc-blende inclusions.
Authors:
;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ; ; ; ;  [5]
  1. Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom)
  2. (United Kingdom)
  3. Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)
  4. CICECO and Dept. Physics, Universidade de Aveiro, 3810-193 Aveiro (Portugal)
  5. Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)
Publication Date:
OSTI Identifier:
22398816
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 13; Other Information: (c) 2015 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; CUBIC LATTICES; ELECTRONIC STRUCTURE; ENERGY GAP; EPITAXY; EV RANGE; FILMS; GALLIUM NITRIDES; LIGHT TRANSMISSION; NANOSTRUCTURES; SCANDIUM COMPOUNDS; SCANNING ELECTRON MICROSCOPY; STACKING FAULTS; TRANSMISSION ELECTRON MICROSCOPY; ZINC SULFIDES