In this report, the effect of heat treatment on the thermoelectric properties and electrical characteristics of electrodeposited Bi 2Te 3 films was studied. Different film compositions from 58.9 at.%Te to 62.9 at.%Te were controlled by the diffusion-controlled method through a rotating electrode. With film composition as parameter, the deposited films with and without heat treatment were characterized by X-ray diffraction, scanning electron microscopy, and Hall effect measurements. The results showed that the Seebeck coefficient has been increased because of the heat treatment. The maximum value of 120.9 μV/K occurred at 58.9%Te and then decreased to both Bi-rich and Te-rich sides.