Thermoelectric properties of MeV Si ion bombarded Bi2Te3/Sb2Te3 superlattice deposited by magnetron sputtering

In order to keep the stoichiometry of Bi2Te3 and Sb2Te3, with the purpose of preserving the electrical and thermal conductivity advantage of the layered structure of bulk Bi2Te3 and Sb2Te3 in each period of the superlattice, magnetron sputtering, which is operated at relatively low temperature, was used to deposit multilayer Bi2Te3/Sb2Te3 thermoelectric superlattice devices. In addition to the effect of quantum well confinement of the phonon transmission, the nanoscale clusters produced by bombardment with an ion beam further adversely affects the thermal conductivity. The increase of the electron density of states in the miniband of nanoscale cluster quantum dot-like structure formed by bombardment also increases the Seebeck coefficient and the electrical conductivity. Eventually, the thermoelectric figure of merit of superlattice films increases.