OPTICAL PROPERTIES OF AsSeTl THIN FILMS DEPOSITED BY e-BEAM EVAPORATION TECHNIQUE

Abstract

Five compositions of the system As 25 Se 75-x Tl x (x = 12, 16, 20, 24 and 28%) have been prepared using melt quench technique. Thin films of the same thickness (200 nm) were deposited by electron beam evaporation technique. Optical and other parameters of the films have been studied. The optical band gap E op found to decrease by increasing the coordination number r and average number of bonds per atom N av and by decreasing the heat of atomization H s . Other parameters as an oscillator energy E o , dispersion energy E d and plasma frequency ω p found to be affected by changing thallium content.