Thermoelectric behaviour of (Bi0.5Sb0.5)2Te3 semiconducting alloy thin films

The Jain-Verma theory has been applied to the thermoelectric data of vacuum flash-evaporated and annealed polycrystalline thin films of (Bi0.5Sb0.5)(2)Te-3 alloys of different thicknesses to study the nature of principal carrier scattering mechanism and also to know the extent of other scattering mechanisms, simultaneously. It is found that the value of the energy dependent scattering index parameter lies between -0.45 and -0.4. This indicates that, even though the principal scattering mechanism in the films is the normal lattice scattering, other scattering like 'impurity' scattering, surface scattering and grain boundary scattering may be present. (C) 2001 Elsevier Science Ltd. All rights reserved.