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Title: Effects of Phonon Coupling and Free Carriers on Band-edge Emission at Room Temperature in n-type ZnO Crystals

Abstract

Room-temperature photoluminescence has been studied in n-type bulk ZnO crystals representing three different growth methods and having free-carrier concentrations (n) ranging from 10{sup 13} to 10{sup 18} cm{sup -3}. The near-band-edge emission has both free-exciton and free-exciton-phonon contributions, with the strength of the phonon coupling dependent on sample defect concentrations. Band-gap shrinkage effects are used to explain a decrease in emission energy for the higher n values. Band filling and band nonparabolicity are predicted to be important for n>10{sup 19} cm{sup -3}. At 300 K, in the absence of free carriers, the free-exciton energy is 3.312{+-}0.004 eV.

Authors:
 [1];  [1];  [2];  [2];  [3];  [3]
  1. West Virginia University
  2. Air Force Research Laboratory
  3. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
Work for Others (WFO)
OSTI Identifier:
931672
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 89; Journal Issue: 25
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; DEFECTS; PHONONS; PHOTOLUMINESCENCE; SHRINKAGE; ZINC OXIDES

Citation Formats

Giles, N. C., Xu, Chunchuan, Callahan, M. J., Wang, Buguo, Neal, John S, and Boatner, Lynn A. Effects of Phonon Coupling and Free Carriers on Band-edge Emission at Room Temperature in n-type ZnO Crystals. United States: N. p., 2006. Web. doi:10.1063/1.2410225.
Giles, N. C., Xu, Chunchuan, Callahan, M. J., Wang, Buguo, Neal, John S, & Boatner, Lynn A. Effects of Phonon Coupling and Free Carriers on Band-edge Emission at Room Temperature in n-type ZnO Crystals. United States. doi:10.1063/1.2410225.
Giles, N. C., Xu, Chunchuan, Callahan, M. J., Wang, Buguo, Neal, John S, and Boatner, Lynn A. Sun . "Effects of Phonon Coupling and Free Carriers on Band-edge Emission at Room Temperature in n-type ZnO Crystals". United States. doi:10.1063/1.2410225.
@article{osti_931672,
title = {Effects of Phonon Coupling and Free Carriers on Band-edge Emission at Room Temperature in n-type ZnO Crystals},
author = {Giles, N. C. and Xu, Chunchuan and Callahan, M. J. and Wang, Buguo and Neal, John S and Boatner, Lynn A},
abstractNote = {Room-temperature photoluminescence has been studied in n-type bulk ZnO crystals representing three different growth methods and having free-carrier concentrations (n) ranging from 10{sup 13} to 10{sup 18} cm{sup -3}. The near-band-edge emission has both free-exciton and free-exciton-phonon contributions, with the strength of the phonon coupling dependent on sample defect concentrations. Band-gap shrinkage effects are used to explain a decrease in emission energy for the higher n values. Band filling and band nonparabolicity are predicted to be important for n>10{sup 19} cm{sup -3}. At 300 K, in the absence of free carriers, the free-exciton energy is 3.312{+-}0.004 eV.},
doi = {10.1063/1.2410225},
journal = {Applied Physics Letters},
number = 25,
volume = 89,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
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