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Title: Two-band luminescence from an intrinsic defect in spherical and terraced MgO nanoparticles

Luminescent defect centers in wide bandgap materials such as MgO are of great interest for science and technology. Magnesium oxide nanocubes obtained by the self-combustion of Mg metal have long exhibited only a broad 2.9 eV cathodoluminescence band owing to oxygen vacancies (F centers). However, in this work, a room-temperature ultraviolet 4.8 eV cathodoluminescence band has been observed coincident with a 2.5 eV band of the same intensity from an unexplored intrinsic defect in MgO terraced nanocubes and nanospheres produced from Mg metal combustion in an H{sub 2}/O{sub 2} flame. Synchrotron radiation excitation spectra reveal that the excitation energy at the onset of both bands is just above the bandgap energy of 7.7 eV, where electrons and holes are generated. We determine that a defect, responsible for both emission bands, creates proximal anion-cation vacancy pairs named P centers that may appear instead of F centers because of changes in the MgO nanoparticle growth conditions.
Authors:
; ; ; ; ;  [1] ;  [2] ;  [3] ;  [4]
  1. Global Frontier Center for Multiscale Energy Systems, Division of WCU Multiscale Mechanical Design, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)
  2. Deparment of Physics, Faculty of Science, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560 (Japan)
  3. UVSOR Facility, Institute for Molecular Science and the Graduate University for Advanced Studies, Okazaki 444-8585 (Japan)
  4. Department of Electrical and Electronics Engineering, Faculty of Engineering, University of Fukui, Fukui 910-8507 (Japan)
Publication Date:
OSTI Identifier:
22399015
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 18; 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; ANIONS; CATHODOLUMINESCENCE; CATIONS; ELECTRONS; ENERGY GAP; EV RANGE; EXCITATION; F CENTERS; HOLES; HYDROGEN; MAGNESIUM; MAGNESIUM OXIDES; NANOPARTICLES; OXYGEN; SPHERICAL CONFIGURATION; SYNCHROTRON RADIATION; TEMPERATURE RANGE 0273-0400 K; ULTRAVIOLET RADIATION