skip to main content

Title: The origin of white luminescence from silicon oxycarbide thin films

Silicon oxycarbide (SiC{sub x}O{sub y}) is a promising material for achieving strong room-temperature white luminescence. The present work investigated the mechanisms for light emission in the visible/ultraviolet range (1.5–4.0 eV) from chemical vapor deposited amorphous SiC{sub x}O{sub y} thin films, using a combination of optical characterizations and electron paramagnetic resonance (EPR) measurements. Photoluminescence (PL) and EPR studies of samples, with and without post-deposition passivation in an oxygen and forming gas (H{sub 2} 5 at. % and N{sub 2} 95 at. %) ambient, ruled out typical structural defects in oxides, e.g., Si-related neutral oxygen vacancies or non-bridging oxygen hole centers, as the dominant mechanism for white luminescence from SiC{sub x}O{sub y}. The observed intense white luminescence (red, green, and blue emission) is believed to arise from the generation of photo-carriers by optical absorption through C-Si-O related electronic transitions, and the recombination of such carriers between bands and/or at band tail states. This assertion is based on the realization that the PL intensity dramatically increased at an excitation energy coinciding with the E{sub 04} band gaps of the material, as well as by the observed correlation between the Si-O-C bond density and the PL intensity. An additional mechanism for the existence of a blue componentmore » of the white emission is also discussed.« less
Authors:
; ; ;  [1] ; ; ;  [2]
  1. College of Nanoscale Sciences and Engineering, State University of New York, Albany, New York 12203 (United States)
  2. Department of Physics and Astronomy, University of Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium)
Publication Date:
OSTI Identifier:
22283097
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 6; 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; CHARGE CARRIERS; CHEMICAL VAPOR DEPOSITION; ELECTRON SPIN RESONANCE; ELECTRONIC STRUCTURE; EXCITATION; HOLES; OXYGEN; PHOTOLUMINESCENCE; SILICON; SILICON CARBIDES; TEMPERATURE RANGE 0273-0400 K; THIN FILMS; ULTRAVIOLET RADIATION; VACANCIES