Thermoelectric Transport in Surface- and Antimony-Doped Bismuth Telluride Nanoplates

We report the in-plane thermoelectric properties of suspended (Bi1-xSbx)(2)Te-3 nanoplates with x ranging from 0.07 to 0.95 and thicknesses ranging from 9 to 42 nm. The results presented here reveal a trend of increasing p-type behavior with increasing antimony concentration, and a maximum Seebeck coefficient and thermoelectric figure of merit at x similar to 0.5. We additionally tuned extrinsic doping of the surface using a tetrafluoro-tetracyanoquinodimethane (F-4-TCNQ) coating. The lattice thermal conductivity is found to be below that for undoped ultrathin Bi2Te3 nanoplates of comparable thickness and in the range of 0.2-0.7 W m(-1) K-1 at room temperature. (C) 2016 Author(s).