횡 방향 열전성능 향상을 위한 써모파일 열전소자 디자인 최적화

Abstract

A conventional thermoelectric (TE) device that uses the Seebeck effect is a longitudinal device where the electric field is parallel to the thermal gradient and the output voltage increases with the total number of the thermoelectric legs. As the changes in the device design are essential where they can enhance their functionality and output performances, many designs have been suggested to enhance the efficiency of the longitudinal Seebeck-based TE devices[1]. The transverse TE device that uses anomalous Nernst effect (ANE) generates electric field perpendicular to the thermal gradient due to the material’s magnetization. The output voltage increases with the transverse length as long as a temperature gradient is present, and it is well-suited for use in thin materials[2]. However, the efficiency of the transverse TE devices is still low for practical application compared to the longitudinal TE devices and requires further improvements. Yet, few designs of the transverse TE devices, such as the thermopile and coil structure, have been reported thus far to improve their performances[3]. Here we report a novel design of the transverse TE device. By modifying the geometry of the TE legs into a tilted structure and by changing the location of the electrodes, the transverse TE voltage can be enlarged with an additional localized heat flow parallel with the transverse direction. This design shows that the output voltage can be improved by combining the ANE voltage with the Seebeck voltage along the transverse direction.