Thermal annealing dependence of some physical properties of Bi-substituted Sn–Sb–Se glassy thin films

¹ Semiconductors Laboratory, Department of Applied Physics, Guru Nanak Dev University, Amritsar, 143005 Punjab, India
² Department of Physics, University of Botswana, Botswana

Corresponding author: rthangaraj@rediffmail.com

Received: 10 March 2009
Accepted: 23 March 2009
Published online: 10 June 2009

Abstract

Bulk glasses of the Sn₁₀SbBi_xSe₇₀ (0 x ≤ 8) system were prepared by the conventional melt quenching technique. Thin films were prepared by the thermal evaporation technique on glass substrates. Appearance of some crystalline phases is observed from the X-ray diffractograms after heat treatment below the glass transition temperature for 1 h. Scanning electron microscopy studies also show the presence of microcrystalline phases in the amorphous matrix after annealing for 1 h. The effect of Bi concentration and heat treatment on the optical gap and activation energy for dark conductivity were also investigated for the pristine as well as annealed films. The results are discussed on the basis of models related to the presence of defect states in chalcogenide materials.