Electrical conduction in ordered defect compounds

A comparative study of the temperature dependence of electrical resistivity, carrier concentration and carrier mobility of the Ordered Defect Compounds (ODCs) CuIn3Se5, CuIn3Te5, and CuIn5Te8 with their corresponding normal 1:1:2 phase is reported. Relatively lower carrier concentration and higher activation energy observed in ODCs is explained on the basis that shallow acceptor or donor levels observed in 1: 1:2 phase are partially annihilated in these compounds due to attractive interaction between V-Cu(-1) and In-Cu(+2) defect pair. In the activation regime, the mobility is explained by taking into account a scattering mechanism of the charge carriers with donor-acceptor defect pairs. The electrical data at lower temperatures is explained with the existing theoretical expression for the nearest neighbor hopping conduction mechanism. (C) 2003 Elsevier Ltd. All rights reserved.