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Effect of SP3/(SP2+SP3) Carbon Fraction on the Photoelectric Threshold and Electron Affinity of Diamond Films

Published online by Cambridge University Press:  10 February 2011

I.A. Akwani ,
E.D. Sosa ,
S.C. Lim ,
R.E. Stallcup II ,
J.N. Castillega ,
J. Bernhard ,
D.E. Golden  and
J.M. Perez
I.A. Akwani
Affiliation:
Physics Department, University of North Texas, Denton, TX 76203
E.D. Sosa
Affiliation:
Physics Department, University of North Texas, Denton, TX 76203
S.C. Lim
Affiliation:
Physics Department, University of North Texas, Denton, TX 76203
R.E. Stallcup II
Affiliation:
Physics Department, University of North Texas, Denton, TX 76203
J.N. Castillega
Affiliation:
Physics Department, University of North Texas, Denton, TX 76203
J. Bernhard
Affiliation:
Physics Department, University of North Texas, Denton, TX 76203
D.E. Golden
Affiliation:
Physics Department, University of North Texas, Denton, TX 76203
J.M. Perez
Affiliation:
Physics Department, University of North Texas, Denton, TX 76203
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Abstract

We report a significant decrease in the photoelectric threshold of chemical vapor deposition grown diamond films as the fraction of sp3 carbon to sp2 plus sp3 carbon in the films decreases. Raman spectroscopy and x-ray photoelectron spectroscopy are used to characterize the different forms of carbon in the films and the sp3/(sp2 + sp3) carbon fraction at the surface. We observe a decrease in the photoelectric threshold from 4.5 eV to 3.9 eV as the sp3/(sp2 + sp3) carbon fraction at the surface decreases from 71% to 55%. Ultraviolet photoelectron spectroscopy of the films shows that they have a negative electron affinity surface. Therefore, the work function of the films decreases from 4.5 eV to 3.9 eV. We propose that the decrease in photoelectric threshold is due to a decrease in the band gap of sp2-sp3 carbon networks at the grain boundaries. The observed decrease in photoelectric threshold can be used to tailor the electronic properties of diamond films for specific applications.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 509: Symposium C – Materials Issues in Vacuum Microelectronics , 1998 , 137
Copyright
Copyright © Materials Research Society 1998

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References

1 Breskin, A., Chechik, R., Shefer, E., Bacon, D., Avigal, Y., Kalish, R., and Lifshitz, Y., Appl. Phys. Lett. 70, 3446 (1997).Google Scholar
2 Zhu, W., Kochansk, G.P., Jin, S., and Seibles, L., J. Vac. Sci. Technol. B 14, 2011 (1996).Google Scholar
3 Malta, D.P., Posthill, J.B., Humphreys, T.P., Appl. Phys. Lett. 64, 1929 (1994).Google Scholar
4 Yarbrough, W.A. and Messier, R., Science 247, 688 (1990).Google Scholar
5 Fallon, P.J. and Brown, L.M., Diam. Relat. Mater. 2, 1004 (1994).Google Scholar
6 Waite, M.M. and Shah, S.I., Appl. Phys. Lett. 60, 2344 (1992).Google Scholar
7 Krainsky, I.L., Asnin, V.M., Mearini, G.T., and Dayton, J.A., Phys. Rev. B 53, R7650 (1996).Google Scholar
8 Sen, R., Sumathy, R., and Rao, C.N.R., J. Mater. Res. 11, 2961 (1996).Google Scholar
9 See, for example, Dalven, R., Introduction to Applied Solid State Physics (Plenum Press, New York, 1980).Google Scholar