NONLINEAR I-V BEHAVIOUR & THERMOELECTRIC MEASUREMENTS IN AMORPHOUS SEMICONDUCTING As-Te-I SYSTEM.

Amorphous semiconducting compound of the composition As//4//0Te//3//0I//2//0 is studied for its I-V characteristics and thermoelectric effects. It has been observed that the I-V characteristic is nonlinear in nature. This is explained on the basis of charged defect-states existing in As//5//0Te//3//0I//2//0 system. The thermoelectric power increases with increasing temperature, but at higher temperatures it is found to decrease. This is explained as due to existence of As//2Te//3 ribbons and small-polaron hopping motion of holes in the particular site geometry which is expected to occur in these ribbons. The charged defect-state model successfully explains the nonlinear I-V behavior and the thermoelectric data observed experimentally.