Role of Sn in the Density of Defect States in a-Se0.75Te0.25 and a-Se0.85Te0.15Thin Films

Authors : N. SHARMA, S. KUMAR

Pages : 161-167

Doi:10.3906/zoo-1209-2

View : 14 | Download : 2

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :In this paper we report the effect of Sn incorporation in the density of defect states of two binary Se-Te glassy systems, comparing the properties of a-Se0.75Te0.25, a-Se0.85Te0.15 and a-Se0.75Te0.15Sn0.10 glassy alloys. Properties of d.c. conductivity at high electric fields in vacuum were examined; and current-voltage insert ignore into journalissuearticles values(I-V); characteristics have been measured at various fixed temperatures. Ohmic behavior is observed at low electric fields; while at high electric fields insert ignore into journalissuearticles values(E \sim 104 V/cm);, non-ohmic behavior is observed. An analysis of the experimental data confirms the presence of space charge limited conduction insert ignore into journalissuearticles values(SCLC); in the studied glassy materials. Density of defect states insert ignore into journalissuearticles values(DOS); near Fermi level is calculated by fitting data to SCLC theory. The peculiar role of the third element Tin, as an impurity in the pure binary Se0.75Te0.25 and Se0.85Te0.15 glassy alloys, is also discussed in terms of electro-negativity difference.
Keywords : Thin films, Chalcogenide glasses, SCLC, DOS