Astudy the electrical properties of a- Sc:2.5%As thin films prepared by Thermal evaporation in Vacuum

.Thin films of Se:2.5%As were deposited on a glass substrates by thermal coevaporation technique under high vacuum at different thickness (950,2400,3500,4300)A within the range temperature (293-373)K and studied the electrical properties before and after annealing. The result shown that the D.C conductivity increases and decreases in activation energy. There were two activation energies indicating different conductivity mechanisms in the gap. f r om the llall c i t e d experiment, the charge carriers are electrons and there concentration (n) were observed to decrease with increasing the thickness. The thermopoWer results confirmed the sign of I kill effect measurements