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Title: Enhanced field emission from lanthanum hexaboride coated multiwalled carbon nanotubes: Correlation with physical properties

Detailed results from field emission studies of lanthanum hexaboride (LaB{sub 6}) coated multiwalled carbon nanotube (MWCNT) films, pristine LaB{sub 6} films, and pristine MWCNT films are reported. The films have been synthesized by a combination of chemical and physical deposition processes. An impressive increase in field enhancement factor and temporal stability as well as a reduction in turn-on field and threshold field are observed in LaB{sub 6}-coated MWCNTs compared to pristine MWCNT and pristine LaB{sub 6} films. Surface morphology of the films has been examined by scanning electron microscopy. Introduction of LaB{sub 6} nanoparticles on the outer walls of CNTs LaB{sub 6}-coated MWCNTs films is confirmed by transmission electron microscopy. The presence of LaB{sub 6} was confirmed by X-ray photoelectron spectroscopy results and further validated by the Raman spectra. Raman spectroscopy also shows 67% increase in defect concentration in MWCNTs upon coating with LaB{sub 6} and an upshift in the 2D band that could be attributed to p-type doping. Ultraviolet photoelectron spectroscopy studies reveal a reduction in the work function of LaB{sub 6}-coated MWCNT with respect to its pristine counterpart. The enhanced field emission properties in LaB{sub 6}-coated MWCNT films are correlated with a change in microstructure and work function.
Authors:
;  [1] ; ; ; ;  [2] ; ;  [3] ;  [4] ; ;  [5] ;  [4] ;  [6]
  1. Nanostech Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India)
  2. Semiconductor Physics, Technische Universität Chemnitz, 09107 Chemnitz (Germany)
  3. Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016 (India)
  4. Department of Materials for Nanoelectronics, Technische Universität Chemnitz, 09107 Chemnitz (Germany)
  5. Solid Surfaces Analysis, Technische Universität Chemnitz, 09107 Chemnitz (Germany)
  6. (Germany)
Publication Date:
OSTI Identifier:
22308184
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; CARBON NANOTUBES; CORRELATIONS; DEPOSITION; FIELD EMISSION; FILMS; LANTHANUM BORIDES; MICROSTRUCTURE; NANOPARTICLES; PHYSICAL PROPERTIES; RAMAN SPECTRA; RAMAN SPECTROSCOPY; SCANNING ELECTRON MICROSCOPY; STABILITY; SURFACES; TRANSMISSION ELECTRON MICROSCOPY; ULTRAVIOLET RADIATION; WORK FUNCTIONS; X-RAY PHOTOELECTRON SPECTROSCOPY