Jpn. J. Appl. Phys. 33 (1994) pp. 6611-6615 |Next Article| |Table of Contents|
|Full Text PDF (725K)| |Buy This Article|
Photoconductivity of Ultrathin Zinc Oxide Films
Department of Chemistry, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu 501-11
1First Research Department, Research & Development Division, NOK CORPORATION,
4-3-1 Tsujido-Shinmachi, Fujisawa 251
(Received July 11, 1994; accepted for publication September 17, 1994)
Electrical and photoelectrical properties of nondoped and doped zinc oxide films coated on glass plates by the
dip-coating method are investigated at room temperature in various ambient atmospheres. The dark conductivity
of the nondoped films exponentially decreased with decreasing film thickness while the conductivity under illumination of 350 nm light was almost constant at 100 S·cm-1 irrespective of the film thickness. Consequently thinner
films showed larger photoresponse than thicker films. This thickness dependence is explained by the variation of
ZnO particle size with the film thickness (fine particle model) and the additional effect of the Schottky barrier
generated between the film and gold electrodes.
KEYWORDS:ZnO thin films, photoconduction, gas sensing, sol-gel method, n-type oxide semiconductors
- D. A. Melnick:
J. Chem. Phys. 26 (1957) 1136[AIP Scitation].
- R. Keezer:
J. Appl. Phys. 35 (1961) 1866[AIP Scitation].
- R. R. Addiss, Jr. and F. G. Wakim: Photogr. Sci. Eng. 13 (1969) 111.
- Y. Takahashi, A. Ogiso, R. Tomoda, K. Sugiyama, H. Minoura and M. Tsuiki: J. Chem. Soc. Faraday Trans. I 78 (1982) 2563.
- J. M. Hermann, J. Disdier, M.-N. Mozzanega and P. Pichat: J. Cat. 60 (1979) 369.
- R. H. Collins and D. G. Thomas:
Phys. Rev. 112 (1958) 388[APS].
- Y. Ohyama, H. Saiki and Y. Takahashi:
J. Mater. Sci. 29 (1994) 4099[CrossRef].
- C. J. Brinker and G. W. Scherer: Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing (Academic Press, New York, 1990) p. 803.
- M. Born and E. Wolf: Principles of Optics (Pergamon Press, New York, 1990) p. 87.
- D. J. Leary, J. O. Bornes and A. G. Jordon: J. Electrochem. Soc. 129 (1982) 1382.
- Y. Mizokawa and S. Nakamura: Shinku 15 (1972) 292 [in Japanese].
- H. Ihokura: Electronic Ceramics 6 (1975) 9 [in Japanese].
- M. Kanamori, M. Takeuchi, Y. Ohya and Y. Takahashi: Chem. Lett. (1994) 2035.