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Title: Origins of optical absorption and emission lines in AlN

To aid the development of AlN-based optoelectronics, it is essential to identify the defects that cause unwanted light absorption and to minimize their impact. Using hybrid functional calculations, we investigate the role of native defects and their complexes with oxygen, a common impurity in AlN. We find that Al vacancies are the source of the absorption peak at 3.4 eV observed in irradiated samples and of the luminescence signals at 2.78 eV. The absorption peak at ∼4.0 eV and higher, and luminescence signals around 3.2 and 3.6 eV observed in AlN samples with high oxygen concentrations are attributed to complexes of Al vacancies and oxygen impurities. We also propose a transition involving Al and N vacancies and oxygen impurities that may be a cause of the absorption band peaked at 2.9 eV.
Authors:
 [1] ;  [2] ; ;  [1] ;  [1] ;  [3]
  1. Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)
  2. (United States)
  3. (Germany)
Publication Date:
OSTI Identifier:
22303482
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 11; 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; ABSORPTION; ALUMINIUM NITRIDES; DEFECTS; EMISSION; EV RANGE; HYBRIDIZATION; IMPURITIES; IRRADIATION; LUMINESCENCE; OXYGEN; SIGNALS; SPECTRA; VACANCIES; VISIBLE RADIATION