Optical and field-emission properties of ZnO nanostructures deposited using high-pressure pulsed laser deposition

T. Premkumar, Y. S. Zhou, Y. F. Lu, K. Baskar

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Abstract

ZnO nanostructures were deposited on GaN (0001), Al2O 3 (0001), and Si (100) substrates using a high-pressure pulsed laser deposition (PLD) method. Vertically aligned hexagonal-pyramidal ZnO nanorods were obtained on the Al2O3 and Si substrates whereas interlinked ZnO nanowalls were obtained on the GaN substrates. A growth mechanism has been proposed for the formation of ZnO nanowalls based on different growth rates of ZnO polar and nonpolar planes. Both ZnO nanorods and nanowalls exhibit a strong E2H vibration mode in the micro-Raman spectra. The corresponding fluorescence spectra of ZnO nanorods and nanowalls showed near band emission at 3.28 eV. The ZnO nanorods grown on the Si substrates exhibited better crystalline and optical properties compared with the ZnO structures grown on the GaN and Al2O3 substrates. The high aspect ratio, good vertical alignment, and better crystallinity of the ZnO nanorods with tapered tips exhibited promising field emission performance with a low turn-on field of 2 V/μm, a high current density of 7.7 mA/cm 2, and a large field enhancement factor.

Original languageEnglish (US)
Pages (from-to)2863-2869
Number of pages7
JournalACS Applied Materials and Interfaces
Volume2
Issue number10
DOIs
Publication statusPublished - Oct 27 2010

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Keywords

  • high-pressure pulsed laser deposition
  • nanorod field-emission properties
  • nanowalls
  • optical properties
  • zinc oxide

ASJC Scopus subject areas

  • Materials Science(all)

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