Thermoelectric hotspot cooling using thermally conductive fillers

•Highlights new perspective on thermoelectric cooler (TEC) design for hotspot cooling.•Proposes the thermally-conductive filler-embedded TEC (F-TEC) as an example.•Demonstrates F-TEC has 42.5% higher heat-dissipation capability than conventional TEC.•Visualizes temperature gradient applied to thermoelectric legs using an IR camera.•Presents additional considerations for improving the F-TEC. The commercial applications of thermoelectric coolers (TECs) are limited to niche markets owing to their low cooling efficiency. For hotspot cooling, in which the Fourier heat is added to the Peltier heat, thermoelectric (TE) materials should possess both large power factors and high thermal conductivities. However, the interdependence among TE material properties renders the development of such materials challenging. Herein, we provide a design strategy of TEC that addresses these material challenges at the device level. As proof of concept, we demonstrate that the cooling capability of filler-embedded TECs (F-TECs), which consist of TE legs with large power factors and a thermally conductive filler material, can be significantly improved compared to that of conventional TEC, owing to the 42.5% enhanced effective thermal conductance. Additionally, infrared imaging shows that the filler can decrease the temperature gradient and maximum temperature of the TE legs, which may improve the thermal stability of the TECs. Our proposed F-TEC concept can facilitate the development of effective TEC devices that can be widely used in hotspot cooling applications, such as in microprocessors, batteries and photovoltaic cells.