ELECTRICAL-CONDUCTIVITY OF AMORPHOUS SEMICONDUCTING-FILMS OF SYSTEM (GE20AS30SE50-XTEX)

The substitution effect of Te, with different concentrations, on the e lectrical and thermal properties of the quaternary chalcogenide semico nducting films Ge20As30Se50-xTe(x), x = 0, 20, 30 and 40, have been st udied. Dependence of d.c. conductivity on composition has been reporte d. It was found that the activation energy decreases with increasing T e content. The obtained results have been interpreted in the frame of the model proposed by Mott and Davis (1979). It has also been observed that the increase of Te was followed by a decrease in the glass trans ition temperature. In other words, the addition of Te decreases the st ability of the formed glass.