Electronic transport properties of the flash-evaporated p-type Bi0.5Sb1.5Te3 thermoelectric thin films

P-type Bi0.5Sb1.5Te3 thermoelectric thin films were deposited by flash evaporation technique, and their properties were investigated. The effective mean free path (EMFP) model was adopted to examine the thickness dependence of the thermoelectric properties. Annealing; effects on the carrier concentration and mobility were also studied, and their variations were analyzed in conjunction with the antistructure defects. Seebeck coefficient and electrical resistivity vs, inverse thickness showed a linear relationship, and the EMFP was found to be 3150 Angstrom. Carrier concentration decreased considerably due to reduction of the antistructure defects, so that electrical conductivity decreased and Seebeck coefficient increased. When annealed at 473 K for 1 h, Seebeck coefficient and electrical conductivity were 160 mu V/K and 610 Ohm(-1) cm(-1) respectively. Therefore, the thermoelectric quality factor was also enhanced to 16 mu W/cm K-2. (C) 2000 Elsevier Science B.V. All rights reserved.