"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

I agree, do not show this message again.

Potential gas sensor applications of semiconductor thin films based on changes in photoresponse

S. REYNOLDS1,2,* , Z. ANEVA3, Z. LEVI3, D. NESHEVA3, C. MAIN2, V. SMIRNOV2

Affiliation

  1. IPV, Forschungszentrum Jülich, D-52425 Jülich, Germany
  2. University of Dundee, Division of Electronic Engineering and Physics, Dundee DD1 4HN, U.K.
  3. Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria

Abstract

A method for improving the discrimination of semiconductor thin-film gas sensors, which utilises the amplitude and phase of the photocurrent response to a modulated light source, is proposed. The photoconductivity of microcrystalline silicon films is examined before and after exposure to the vapour of an iodine solution in ethanol. Preliminary results are presented which suggest that the density and/or capture properties of localised states may be reversibly modified. For cadmium selenide however, a small but systematic temperature-dependent phase lead is observed in this material at low frequencies, even under vacuum-annealed conditions. This is in contrast to present theory, which predicts that for an arbitrary localised state distribution the photocurrent response must lag the applied excitation..

Keywords

Gas sensors, Modulated photoconductivity, Semiconductors, Thin films.

Submitted at: Nov. 1, 2006
Accepted at: Jan. 15, 2007

Citation

S. REYNOLDS, Z. ANEVA, Z. LEVI, D. NESHEVA, C. MAIN, V. SMIRNOV, Potential gas sensor applications of semiconductor thin films based on changes in photoresponse, Journal of Optoelectronics and Advanced Materials Vol. 9, Iss. 1, pp. 209-212 (2007)