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Enhanced Electron Field Emission from Carbon Nanotube Matrices

Published online by Cambridge University Press:  17 March 2011

Archana Pandey
Affiliation:
Department of Physics, Michigan Technological University, 118 Fisher Hall, 1400 Townsend Drive, Houghton, Michigan 49931, U.S.A.
Abhishek Prasad
Affiliation:
Department of Physics, Michigan Technological University, 118 Fisher Hall, 1400 Townsend Drive, Houghton, Michigan 49931, U.S.A.
Yoke Khin Yap
Affiliation:
Department of Physics, Michigan Technological University, 118 Fisher Hall, 1400 Townsend Drive, Houghton, Michigan 49931, U.S.A.
Mark Engelhard
Affiliation:
EMSL, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99354, U.S.A.
Chongmin Wang
Affiliation:
EMSL, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99354, U.S.A.
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Abstract

Field emission from as-grown carbon nanotube (CNTs) films often suffered from high threshold electric field, and low emission site density due to screening effects. These problems can be resolved by patterned growth of CNTs on lithographically prepared catalyst films. However, these approaches are expensive and not applicable for future emitting devices with large display areas. Here we show that as-grown CNTs films can have low emission threshold field and high emission density without using any lithography processes. We have reduced screening effects and work function of as-grown CNTs films and created the novel CNT matrices by addition of vapor- and/or liquid- phase deposition. Furthermore, these CNT matrices can continuous emit electrons for 40 hours without significant degradation. The fabrication of our CNT matrices is described as follows. First, CNT films were grown by plasma-enhanced chemical vapor deposition. These vertically-aligned multiwalled carbon nanotubes (VA-MWCNTs) are having typical length and diameter of 4 microns and 40 nm, respectively. Spacing between these CNTs is ~80 nm in average, leading to poor emission properties due to the screening effect. These as-grown samples were then subjected to the deposition of strontium titanate (SrTiO3) by pulsed-laser deposition to reduce both the work function and screening effect of CNTs. The emission properties of these coated samples can be further improved by fully filled the spaces between VA-MWCNTs by poly-methyl metha acrylate (PMMA). The field emission threshold electric field was decreased from 4.22 V/μm for as-grown VA-MWCNTs to 1.7 V/μm for SrTiO3 coated VA-MWCNTs. The addition filling with PMMA and mechanical polishing can further reduce the threshold to 0.78V/μm for the so called PMMA-STO-CNT matrices. Long term emission stability and emission site density were also enhanced.

Type
Research Article
Copyright
Copyright © Materials Research Society 2011

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References

REFERENCES

1. Ijima, S., Nature (London) 354, 56 (1991).Google Scholar
2. Treacy, M.M.J., Ebbesen, T.W., Gibson, J.M., Nature (London) 381, 678 (1996).10.1038/381678a0Google Scholar
3. Walters, D.A., Ericson, L.M., Casavant, M.J., Liu, J., Colbert, D.T., Smith, K.A. and Smalley, R.E., Appl Phys Lett 74, 3803 (1999).Google Scholar
4. Dresselhaus, M.S., Dresselhaus, G., Avouris, P.. Carbon nanotubes: synthesis, structure, properties, and application (Berlin: Springer 2001) pp. 287-320 Google Scholar
5. deHeer, W.A., Chatelain, A., Ugarte, D.A., Science 270, 1179 (1995).10.1126/science.270.5239.1179Google Scholar
6. Collins, P.G., Zettl, A., Appl Phys Lett 69, 1969 (1996).Google Scholar
7. Choi, W.B., Chung, D.S., Kang, J.H., Kim, H.Y., Jin, Y.W., Han, I.T., Lee, Y.H., Jung, J.E., Lee, N.S., Park, G.S., and Kim, J.M., Appl Phys Lett 75, 3129 (1999).Google Scholar
8. Li, J., Stevens, R., Delzeit, L., Ng, H.T., Cassell, A., Han, J. and Meyyappan, M., Appl Phys Lett 81, 910 (2002).Google Scholar
9. Shiraishi, M. and Ata, M., Carbon 39, 1913 (2001).Google Scholar
10. Yi, W., Jeong, T., Yu, S.G., Heo, J., Lee, C.S., Lee, J.H., Kim, W.S., Yoo, J.B. and Kim, J.M., Adv. Mater 14, 1464 (2002).Google Scholar
11. Bonard, J.M., Klinke, C., Dean, K.A. and Coll, B.F., J.Vac.Sci.Technol. B 26, 1892 (2008).Google Scholar
12. Han, I.T., Kim, H.J., Park, Y., Lee, N., Jang, J.E., Kim, J.W., Jung, J.E., and Kim, J. M., Appl Phys Lett 81, 2070 (2002).Google Scholar
13. Pandey, A., Prasad, A., Moscatello, J., Ulmen, B. and Yap, Y.K., Carbon 48, 287 (2010).Google Scholar
14. Maus-Friedrichs, W., Frerichs, M., Gunhold, A., Krischok, S., Kempter, V., Bihlmayer, G., Surface Science 515, 499 (2002).Google Scholar
15. Pontes, F.M., Lee, E.J.H., Leite, E.R. and Longo, E., Journal of materials science 35, 4783 (2000).Google Scholar
16. Fowler, R. H. and Northeim, L., Proc. R. Soc. A 119, 173 (1928).Google Scholar
17. Bonard, J. M., Klinke, C., Dean, K.A., Coll, B.F., Phys Rev B 67, 115406 1 (2003).Google Scholar
18. Dean, K.A., Burgin, T.P. and Chalamala, B.R., Appl. Phys Lett 79, 1872 (2001).Google Scholar
19. Pandey, A., Prasad, A., Moscatello, J. P. and Yap, Y.K., ACS Nano 4, 6760 (2010).Google Scholar