Engineering Interfacial Effects in Electron and Phonon Transport of Sb 2 Te 3 /MoS 2 Multilayer for Thermoelectric ZT Above 2.0

Efficient thermoelectric (TE) conversion of waste heat to usable energy is a holy grail promising to address major societal issues related to energy crisis and global heat management. For these to be economical, synthesis of a solid‐state material with a high figure‐of‐merit ( ZT ) values is the key, with characterization methods quantifying TE and heat transport properties being indispensable for guiding the development of such materials. In the present study, a large enhancement of the TE power factor in Sb 2 Te 3 /MoS 2 multilayer structures is reported. A new approach is used to simultaneously experimentally determine the values of in‐plane ( k xy ) and out‐of‐pane ( k z ) thermal conductivities for multilayer samples with characteristic layer thickness of few nanometres, essential for the quantification of the ZT , the key parameter for the TE material. Combining simultaneous enhancement in the value of in‐plane power factor (to (4.9 ± 0.4) × mWm −1 K −2 ) and reduction of the in‐plane value of the thermal conductivity (to 0.7 ± 0.1 Wm −1 K −1 ) for Sb 2 Te 3 /MoS 2 multilayer sample led to high values of ZT of 2.08 ± 0.37 at room temperature. The present study, therefore, sets the foundation for a new methodology of exploiting the properties of 2D/3D interfaces for the development of novel fully viable thermoelectric materials.