Approaching high-performance of ordered structure Sb₂Te₃ film via unique angular intraplanar grain boundaries

In this paper, we present an innovative electric-field-assisted magnetron-sputtering deposition method for films preparation. By grain boundary-engineering, we successeful obtained the ordered Sb₂Te₃ film with greatly high figure of merit via controlling external electric field. It has been found that the electric field can induce the change in the angle of intraplanar grain boundaries between (0 1 5) and (0 1 5) planes, which leads to the enhanced holes mobility and maintained low thermal conductivity. The energy filtering takes place at the angular intraplanar grain boundaries. At room temperature, a high ZT value of 1.75 can be achieved in the deposited Sb₂Te₃ film under 30 V external electric field. This is a very promising approach that the electric field induced deposition can develop high-performance Sb₂Te₃-based thermoelectric films.