Electrical and Optical Properties of Ge_<i>x</i>Se_1-<i>x</i>Amorphous Thin Films

Abstract

Measurements of electrical and optical properties have been made on GexSe1-x amorphous thin films of about 1 µm thickness. From the experiment of electrical conductivity at various temperatures, two processes of the d.c. conductivity in GexSe1-x films are observed in plots of ln σ against 1/T. The thermoelectric power exhibits a maximum value of p-type conduction at pure Se and a change of the sign from positive to negative at 0.4<x<0.5. Measurements of the photoconductivity and the absorption spectra have been made at room temperature. It is found that the energy gap is decreased with increasing additions of the Ge content. An energy band model of amorphous GexSe1-x films has been proposed for consistent explanations of experimental data.