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

Journal Article · Tue Oct 28 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4898352· OSTI ID:22308184

Patra, Rajkumar; Sheremet, E.; Rodriguez, R. D.; Lehmann, D.; Zahn, D. R. T. ^[1]; Jha, Menaka; Ganguli, A. K. ^[2]; Schmidt, H. ^[3]; Schulze, S.; Hietschold, M. ^[4]; Schmidt, O. G. ^[3]

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1. Semiconductor Physics, Technische Universität Chemnitz, 09107 Chemnitz (Germany)
2. Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016 (India)
3. Department of Materials for Nanoelectronics, Technische Universität Chemnitz, 09107 Chemnitz (Germany)
4. Solid Surfaces Analysis, Technische Universität Chemnitz, 09107 Chemnitz (Germany)

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.

• OSTI ID: 22308184
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

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