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Title: High optical and structural quality of GaN epilayers grown on (2{sup ¯}01) β-Ga{sub 2}O{sub 3}

Producing highly efficient GaN-based optoelectronic devices has been a challenge for a long time due to the large lattice mismatch between III-nitride materials and the most common substrates, which causes a high density of threading dislocations. Therefore, it is essential to obtain alternative substrates with small lattice mismatches, appropriate structural, thermal and electrical properties, and a competitive price. Our results show that (2{sup ¯}01) oriented β-Ga{sub 2}O{sub 3} has the potential to be used as a transparent and conductive substrate for GaN-growth. Photoluminescence spectra of thick GaN layers grown on (2{sup ¯}01) oriented β-Ga{sub 2}O{sub 3} are found to be dominated by intense bandedge emission. Atomic force microscopy studies show a modest threading dislocation density of ∼10{sup 8 }cm{sup −2}. X-ray diffraction studies show the high quality of the single-phase wurtzite GaN thin film on (2{sup ¯}01) β-Ga{sub 2}O{sub 3} with in-plane epitaxial orientation relationships between the β-Ga{sub 2}O{sub 3} and the GaN thin film defined by (010) β-Ga{sub 2}O{sub 3} || (112{sup ¯}0) GaN and (2{sup ¯}01) β-Ga{sub 2}O{sub 3} || (0001) GaN leading to a lattice mismatch of ∼4.7%. Complementary Raman spectroscopy indicates that the quality of the GaN epilayer is high.
Authors:
;  [1] ; ; ;  [2] ; ; ; ;  [3]
  1. Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia)
  2. IPFN, Instituto Superior Técnico (IST), Campus Tecnológico e Nuclear, Estrada Nacional 10, P-2695-066 Bobadela LRS (Portugal)
  3. Tamura Corporation, Sayama, Saitama 350-1328 (Japan)
Publication Date:
OSTI Identifier:
22311364
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 4; 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; ATOMIC FORCE MICROSCOPY; CRYSTAL GROWTH; DISLOCATIONS; ELECTRICAL PROPERTIES; EPITAXY; GALLIUM NITRIDES; GALLIUM OXIDES; LAYERS; PHOTOLUMINESCENCE; RAMAN SPECTROSCOPY; SPECTRA; SUBSTRATES; THIN FILMS; X-RAY DIFFRACTION