"

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.

LIGHT-INDUCED CHANGES IN THE PHYSICO-CHEMICAL AND OPTICAL PROPERTIES OF THIN Ge-S-Se-As FILMS

J. Tasseva1, K. Petkov1,* , D. Kozhuharova1, Tz. Iliev2

Affiliation

  1. Central Laboratory of Photoprocesses, Bulgarian Academy of Sciences, Acad. G. Bonchev St., bl. 109, 1113 Sofia, Bulgaria
  2. Geological Institute of the Bulgarian Academy of Sciences, Acad. G. Bonchev St., bl. 24, 1113 Sofia, Bulgaria

Abstract

In this paper we report results from studying changes in the optical properties and the microhardness of vacuum deposited thin films from the systems AsxSe100-x (28£x£50) and (As50S50)x(Ge33S67)100-x (0£x£100) depending on the composition and conditions of evaporation and light illumination. Thin films with different compositions of the system As Se-S-Ge were deposited by thermal evaporation of As50Se50 and Ge33S67 from two crucibles changing their evaporation rate. Chalcogenide glasses with compositions As50Se50 and Ge33S67 were chosen because they demonstrate the highest effects of photodarkening (Dl = +50 nm at T = 20%) and photobleaching (Dl = -25 nm at T = 20%), respectively. The exact element content of the films was determined by X-ray microanalysis. The optical transmission and reflection of thin films deposited on BK-7 optical glass substrates were measured in the spectral region of 350-2500 nm and their refractive index and optical band gap Eg were calculated. The photoinduced changes of the foregoing parameters, as well as the changes in their microhardness depending on the composition and the conditions of deposition were traced. Some conclusions about the origin of photoinduced changes in the optical properties of thin films from this multicomponent system are given..

Keywords

Thin chalcogenide films, Optical properties, Photostructural changes.

Submitted at: May 18, 2005
Accepted at: May 26, 2005

Citation

J. Tasseva, K. Petkov, D. Kozhuharova, Tz. Iliev, LIGHT-INDUCED CHANGES IN THE PHYSICO-CHEMICAL AND OPTICAL PROPERTIES OF THIN Ge-S-Se-As FILMS, Journal of Optoelectronics and Advanced Materials Vol. 7, Iss. 3, pp. 1287-1292 (2005)