Bi/Te bilayer thin films were deposited in sequence on oxidized Si wafers by sputtering and converted into Bi2Te3 alloys by thermal annealing. It was found that the Seebeck coefficient rose from -38 μ V/K to -202 μ V/K, the resistivity increased slightly from 2.0 x 10(-3) to 2.3 x 10(-3) &UOmega; cm, and the thermal conductivity decreased from 2.56 to 0.71 W/m K after the Bi/Te bilayer samples were annealed at 200 ° C for 24 h. Bi2Te3 is the only compound phase identified in the annealed Bi/Te bilayer samples by x-ray diffraction analysis. The effects of deposition parameters and postannealing condition on the microstructure and the thermoelectric properties of the Bi/Te bilayer thin films were investigated. © 2005 American Vacuum Society.