Effect of copper on DC and AC conductivities of (As 2Se 3)–(AsI 3) glassy semiconductors

The work is concerned with the effect of copper content on electrical conductivity of the bulk amorphous semiconducting glasses from the system Cu x [(As 2Se 3) 0.9(AsI 3) 0.1] 100 − x ( x = 0, 1, 5 and 10 at.% Cu). The DC conductivity, measured in the temperature range of 300–420 K, shows a semiconducting behaviour of the Arrhenius-type. The AC conductivity was measured in the frequency range of 10 2–10 6 Hz in the temperature interval from 298 to 398 K. Results indicate that the increase of copper content yields a significant increase of the conductivity and a lower activation energy. Dominant conduction mechanisms are the transfer of charge carriers between localized states at the band edges (band tails) and hopping between localized states near the Fermi level. The decreasing temperature dependence of the exponent s points out to the correlated barrier hopping conductivity mechanism.