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Title: Optical signatures of photoinduced Zn vacancies in ZnO single crystal

193-nm excimer laser interaction with ZnO single-crystal at 0.05–500 KW/cm{sup 2} intensities is investigated under ultra high vacuum conditions by time resolved photoluminescence (PL) spectroscopy. A dominant 3.18 eV PL emission band at 295 K is observed. This band shows unusually long 0.52 ± 0.01 μs lifetime, indicating a defect mediated emission mechanism. The demonstrated negative thermal quenching for this band confirms its free electron to acceptor type transition. The involved acceptor is attributed to zinc vacancy with ∼100 meV shallow acceptor state. This study finds that 193-nm interactions produce Zn vacancies in transient states at 0.05–50 KW/cm{sup 2} excitation intensities and in stable state at 500 KW/cm{sup 2} or above intensities. The transient zinc vacancy production at such low intensities further validates the Frenkel pair creation as mechanism for creating these defects in ZnO single-crystal.
Authors:
 [1]
  1. Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814 (United States)
Publication Date:
OSTI Identifier:
22271279
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 1; 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; ELECTRONS; EMISSION SPECTROSCOPY; EXCIMER LASERS; EXCITATION; INTERSTITIALS; LIFETIME; MONOCRYSTALS; PHOTOLUMINESCENCE; PRESSURE RANGE MICRO PA; QUENCHING; TIME RESOLUTION; TRANSIENTS; VACANCIES; ZINC; ZINC OXIDES