2, University of Toledo, Toledo, Ohio, United States
Two-dimensional (2D) van der Waals (vdW) heterostructures have shown multiple functionalities with great potential in electronics and photovoltaics. After scanning many 2DvdW structures, we propose WSe2-MoSe2-WSe2 vdW heterostructure with scandium electrodes as a high performance thermionic energy conversion device. We characterize the device performance using first-principles GW calculations. The proposed device is found to have a room temperature equivalent figure of merit of 1.2 which increases to 3 above 600 K. A high performance with cooling efficiency over 30% of the Carnot efficiency above 450 K is achieved. Due to the large interfacial thermal resistance, thermionic efficiency can be larger than that of a thermoelectric material of same ZT.