Preparation of Bi4Te3 highly oriented nanopillars array film with enhanced electrical properties

The Bi 4 Te 3 films with well-ordered orientation and microstructure were successfully prepared on SiO 2 substrate by a vacuum thermal evaporation deposition technique for the first time. We discussed the effects of evaporation temperature and substrate temperature on the phase and its well-ordered growth of Bi 4 Te 3 films. The formation of Bi 4 Te 3 phase is owing to the differences of the saturated vapor pressure. The thermoelectric transport properties of the Bi 4 Te 3 films were investigated and the (00 l )-oriented nanopillars array film has a better electrical transport performance, whose value of PF is 0.032 mWm −1 K −2 at 339 K, approaching twice that of the non-oriented ordinary film. The enhanced electrical properties of Bi 4 Te 3 films could be achieved via the high-crystallinity well-controlled (00 l )-oriented nanopillars array.