Structural and electrical characterization of semiconducting xCuO-(100-x) TeO2 glasses

Structural, thermal and electrical properties of semiconducting copper tellurite glasses: xCuO-(100-x)TeO2 (x = 30, 40 and 50 mol%) were studied by neutron diffraction, Raman spectroscopy, thermal analysis and two probe electrical conductivity measurements. Reverse Monte Carlo simulations of the neutron structure factors found that Tesingle bondO and Cusingle bondO bonds have equal lengths of 1.94 Å and that both Te and Cu ions exist in structural units of similar size and geometry. The average Cu-O co-ordination decreases from 3.72 to 3.68, while the Te-O co-ordination decreases from 3.48 to 3.34 on increasing the CuO concentration from 30 to 50 mol%. The electrical conductivity increases from 2.96 × 10−9 Ω−1 m−1 to 1.25 × 10−7 Ω−1 m−1 with an increase in CuO concentration from 30 to 50 mol%. The increase in CuO mol% increases the Cusingle bondCu coordination number from 0.68 to 1.26 and promotes electronic hopping between the adjacent Cu sites