"

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.

Anomalous UV-Induced absorption spectra in the Rfsputered In2O3-Sn polycrystalline films

J. EBOTHE1, R. MIEDZINSKI2,* , I. FUKS-JANCZAREK2, A. H. RESHAK2

Affiliation

  1. Universite de Reims, Laboratoire LTME, France
  2. J. Dlugosz University, Czestochowa, Poland

Abstract

Photoinduced absorption of the rf-sputtered indium tin oxide (ITO) thin films doped Sn in concentrations – 2, 4, 5, 6 and 10 % (in weighting units) is studied. We perform photoinducing treatment of the In2O3-Sn films by 1 ns nitrogen laser (λ=337 nm) during illumination up to 10 min. The absorption spectral maximum at 450 nm for the 1 m film samples possessing 2 % and 4 % of Sn is spectrally shifted up to 525 nm for 5 % Sn content. Moreover for 6 % of the Sn one can see an occurrence of the flat absorption maximum, at about 620 nm – 750 nm. With the further increase of the Sn content (up to 10 %) the spectrum becomes similar to that one for 2 % Sn samples. It is established a large spectral shift of the photoinduced absorption band at 500 nm for 2 % Sn content up to 540 nm for the 4 % Sn samples. However, a value of the total absorption changes is almost two times lower. This process is continued for the contents of 5 % and 6 % of Sn. A sign of the photoinduced absorption is changed up to opposite sign for the wavelengths higher than 650 nm. So we observe a phtobleaching. Explanation of the observed non-monotonical content-dependent photoinduced absorption is given within a framework of existed band energy calculations, particularly due to photoinduced shift of the Fermi energy. It is crucial that the effect is observed only for the films deposited by rf-sputtering and is not observed for the films grown by MOCVD, laser plasma ablation and spray pyrolysis. So the role of deposition conditions determining the film properties is crucial. Moreover, excitation by the wavelengths up to 2 μm do not show substantial changes, indicating on an absence of contribution of plasmon states..

Keywords

In2O3, ITO-Sn, Optical absorption.

Submitted at: Aug. 5, 2007
Accepted at: Dec. 7, 2007

Citation

J. EBOTHE, R. MIEDZINSKI, I. FUKS-JANCZAREK, A. H. RESHAK, Anomalous UV-Induced absorption spectra in the Rfsputered In2O3-Sn polycrystalline films, Journal of Optoelectronics and Advanced Materials Vol. 9, Iss. 12, pp. 3803-3807 (2007)