Few-quintuple Bi2Te3 nanofilms as potential thermoelectric materials

The thermoelectric transport properties of p-type Bi2Te3 nanofilms with various quintuple layers (QL) were systematically investigated based on ab initio electronic structure calculations and Boltzmann transport equations. Our results demonstrated that p-type few-quintuple Bi2Te3 nanofilms could exhibit high thermoelectric performance. It was found out that the 1QL Bi2Te3 nanofilm had the highest ZT value as compared with other nanofilms, which is mainly attributed to the significant enhancement of the density of states near the edge of the valence band resulting from the strong coupling between the top and bottom electronic states and the quantum confinement effect. The dependence of the thermoelectric transport properties on carrier concentration and temperature was also discussed in detail, which can be useful for searching high-efficiency few-quintuple Bi2Te3 thermoelectric nanofilms.