Twist-Activated ZT Enhancement in WS 2 /MoS 2 Heterostructures: Twist Angle Dependence of Phonon Transport and Carrier Concentration

In this study, we tuned the thermoelectric properties of the WS 2 /MoS 2 heterojunction by regulating the twist angle. Twist angle regulation changed the carrier distribution of the heterojunction and caused the emergence of the phonon soft mode, resulting in increased conductivity of the heterojunction and decreased thermal conductivity under P/N-type doping. At room temperature, the N-type ZT of the 27.8° twisted heterostructure is 83% higher than that of the untwisted heterojunction under ideal ballistic conditions. Furthermore, the P-type ZT of 16.1 and 27.8° twisted heterostructures are 100% and 75% higher than that of the untwisted heterojunction under ideal ballistic conditions, respectively. These findings provide a theoretical basis for the design of excellent micronano thermoelectric materials and promote the research of torsional electronics and TMDCs-based thermoelectrics.