Enhanced thermoelectric performance of Ga-added Bi0.5Sb1.5Te3 films by flash evaporation

The p-type Ga-added Bi0.5Sb1.5Te3 thermoelectric thin film was deposited on glass substrates by flash evaporation. All elements distributed homogeneously in the matrix and nano- GaSb phase, which was about 20 nm, was found in the TEM image. Due to the addition of Ga, the flash evaporated Ga0.02Bi0.5Sb1.5Te3 film showed higher Seebeck coefficient and the maximal Seebeck coefficient reached 216 μV/K at 400 K. The power factor of Ga0.02Bi0.5Sb1.5Te3 film reached 22 μW cm−1K−2 at room temperature, which was higher than that of Bi0.5Sb1.5Te3 thin film.