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Title: Pulsing frequency induced change in optical constants and dispersion energy parameters of WO{sub 3} films grown by pulsed direct current magnetron sputtering

In this work, we present the pulsing frequency induced change in the structural, optical, vibrational, and luminescence properties of tungsten oxide (WO{sub 3}) thin films deposited on microscopic glass and fluorine doped tin oxide (SnO{sub 2}:F) coated glass substrates by pulsed dc magnetron sputtering technique. The WO{sub 3} films deposited on SnO{sub 2}:F substrate belongs to monoclinic phase. The pulsing frequency has a significant influence on the preferred orientation and crystallinity of WO{sub 3} film. The maximum optical transmittance of 85% was observed for the film and the slight shift in transmission threshold towards higher wavelength region with increasing pulsing frequency revealed the systematic reduction in optical energy band gap (3.78 to 3.13 eV) of the films. The refractive index (n) of films are found to decrease (1.832 to 1.333 at 550 nm) with increasing pulsing frequency and the average value of extinction coefficient (k) is in the order of 10{sup −3}. It was observed that the dispersion data obeyed the single oscillator of the Wemple-Didomenico model, from which the dispersion energy (E{sub d}) parameters, dielectric constants, plasma frequency, oscillator strength, and oscillator energy (E{sub o}) of WO{sub 3} films were calculated and reported for the first time due to variation inmore » pulsing frequency during deposition by pulsed dc magnetron sputtering. The E{sub o} is change between 6.30 and 3.88 eV, while the E{sub d} varies from 25.81 to 7.88 eV, with pulsing frequency. The Raman peak observed at 1095 cm{sup −1} attributes the presence of W-O symmetric stretching vibration. The slight shift in photoluminescence band is attributed to the difference in excitons transition. We have made an attempt to discuss and correlate these results with the light of possible mechanisms underlying the phenomena.« less
Authors:
 [1] ;  [2] ;  [3]
  1. Department of Physics, Alagappa University, Karaikudi 630 004 (India)
  2. Directorate of Distance Education, Alagappa University, Karaikudi 630 004 (India)
  3. Department of Physics, Alagappa Chettiar College of Engineering and Technology, Karaikudi 630 004 (India)
Publication Date:
OSTI Identifier:
22271186
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; 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; DIRECT CURRENT; DOPED MATERIALS; EXCITONS; FLUORINE COMPOUNDS; FREQUENCY DEPENDENCE; GLASS; GRAIN ORIENTATION; LANGMUIR FREQUENCY; MONOCLINIC LATTICES; OSCILLATOR STRENGTHS; PERMITTIVITY; PHOTOLUMINESCENCE; REFRACTIVE INDEX; SPUTTERING; SUBSTRATES; THIN FILMS; TIN OXIDES; TUNGSTEN OXIDES; VISIBLE RADIATION