Fabrication of n-type Bismuth-Telluride Thin Films by Flash Evaporation Method

n-type bismuth-telluride thin films are fabricated by flash evaporation method. Effects of hydrogen annealing on the thin films are investigated for potential application in micro thermoelectric devices. The thin films are grown up to 1 μm on a glass substrate by flash evaporation method. The hydrogen annealing is carried out in the temperature range between 200-350℃ on an atmospheric pressure. The electrical resistivity and Seebeck coefficient are measured at room temperature. Both the electrical resistivity and Seebeck coefficient are improved by the treatment of hydrogen annealing, then the power factor of the n-type bismuth-telluride thin film reaches 8.8μW・cm^・K^2 at annealing temperature of 350℃. The structure of the thin films, which is composition and crystallinity, is studied by electron probe micro analyzer and X-ray diffraction pattern, respectively. The composition of bismuth-telluride thin films is relativity constant until higher annealing temperature. The X-ray diffraction patterns indicate that the crystallinity of the thin films is improved as higher annealing temperature