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Title: Coloration and oxygen vacancies in wide band gap oxide semiconductors: Absorption at metallic nanoparticles induced by vacancy clustering—A case study on indium oxide

In this paper, we show by optical and electron microscopy based investigations that vacancies in oxides may cluster and form metallic nanoparticles that induce coloration by extinction of visible light. Optical extinction in this case is caused by generation of localized surface plasmon resonances at metallic particles embedded in the dielectric matrix. Based on Mie's approach, we are able to fit the absorption due to indium nanoparticles in In{sub 2}O{sub 3} to our absorption measurements. The experimentally found particle distribution is in excellent agreement with the one obtained from fitting by Mie theory. Indium particles are formed by precipitation of oxygen vacancies. From basic thermodynamic consideration and assuming theoretically calculated activation energies for vacancy formation and migration, we find that the majority of oxygen vacancies form just below the melting point. Since they are ionized at this temperature they are Coulomb repulsive. Upon cooling, a high supersaturation of oxygen vacancies forms in the crystal that precipitates once the Fermi level crosses the transition energy level from the charged to the neutral charge state. From our considerations we find that the ionization energy of the oxygen vacancy must be higher than 200 meV.
Authors:
; ; ; ; ; ; ; ;  [1] ; ;  [2]
  1. Leibniz-Institut für Kristallzüchtung, Max-Born-Straße 2, 12489 Berlin (Germany)
  2. CNRS, Laboratoire de Physique des Solides, Université Paris-Sud XI, 91405 Orsay (France)
Publication Date:
OSTI Identifier:
22278151
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 5; 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; 77 NANOSCIENCE AND NANOTECHNOLOGY; ABSORPTION; ACTIVATION ENERGY; CHARGE STATES; COLORATION; CRYSTALS; DIELECTRIC MATERIALS; ELECTRON MICROSCOPY; FERMI LEVEL; INDIUM; INDIUM OXIDES; MELTING POINTS; NANOSTRUCTURES; OXYGEN; PARTICLES; PRECIPITATION; SEMICONDUCTOR MATERIALS; SUPERSATURATION; VACANCIES; VISIBLE RADIATION