Enhanced thermoelectric figure of merit at near room temperature in n-type binary silver telluride nanoparticles
Amish Kumar Gautam, Neeraj Khare
Abstract
In the present study, we have synthesized Ag2Te nanoparticles using the hydrothermal method and showed significant improvement in the thermoelectric properties compared to the bulk Ag2Te sample. Ag2Te nanoparticles showed the highest figure of merit (zT) of 1.37 at 373 K, which is the highest zT reported for this undoped material. This high zT in Ag2Te nanoparticles is mainly due to about ∼2 times higher electrical conductivity (1967 S/cm) and subsequently ∼ 2 times lower thermal conductivity (0.53 W/(m·K)) as compared to the bulk Ag2Te sample. The higher electrical conductivity in Ag2Te nanoparticles can be accredited for two reasons (i) better mobility of the charge carrier and (ii) increased carrier concentration. The low thermal conductivity is associated with the enhanced scattering of phonons at the interface of the Ag2Te nanoparticles.