Size dependence of electrical resistivity and energy bandgap of semiconducting (Bi0.4Sb0.6)2Te3 thin films

Electrical resistivity measurements have been carried out on flash evap orated (Bi0.4Sb0.6)(2)Te-3 thin films. From the temperature dependence of electrical resistivity, the activation energy for conduction in the films was calculated and it was found to be thickness dependent. The reciprocal thickness dependence of electrical resistivity observed has been explained by the 'effective mean free path model' of classical size effect. The energy band gap has been calculated from the optical absorbence data for different thickness films. The observed thickness dependence of optical energy band gap has been explained based on the quantum size effect.