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Title: Determination of carrier concentration dependent electron effective mass and scattering time of n-ZnO thin film by terahertz time domain spectroscopy

We demonstrated a novel and widely accessible method for determining the electron effective mass and scattering time of ZnO films with different carrier concentrations by combining terahertz time-domain spectroscopy with Hall measurement. The terahertz time domain spectroscopy (THz-TDS) transmission spectra (0.1–2THz) were well described by Drude model. It is found that electron effective mass varied from 0.23m{sub 0} to 0.26m{sub 0} as the electron concentration changes from 5.9 × 10{sup 17} cm{sup −3} to 4.0 × 10{sup 19} cm{sup −3}. The carrier concentration dependent characteristic is ascribed to the non-parabolicity of conduction band. Free carrier localization mechanism explained the discrepancy in mobilities obtained from THz-TDS and Hall measurements.
Authors:
;  [1] ;  [2] ;  [1] ; ;  [3] ;  [4] ;  [5] ;  [6] ;  [1] ;  [2] ;  [2]
  1. Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)
  2. (Singapore)
  3. Institute of Materials and Research Engineering, Agency for Science, Technology and Research, 3 Research Link, Singapore 117602 (Singapore)
  4. Department of Chemical and Bioengineering, National University of Singapore, Singapore 117542 (Singapore)
  5. Department of Physics, National University of Singapore, Singapore 117542 (Singapore)
  6. NUSNNI-Nanocore, National University of Singapore, Singapore 117576 (Singapore)
Publication Date:
OSTI Identifier:
22275832
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 3; 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; ABSORPTION SPECTRA; ABSORPTION SPECTROSCOPY; CARRIER MOBILITY; CHARGE CARRIERS; CONCENTRATION RATIO; EFFECTIVE MASS; ELECTRONIC STRUCTURE; ELECTRONS; N-TYPE CONDUCTORS; THIN FILMS; ZINC OXIDES