Insights into Low-Dimensional Electronic Structures for Improved Thermoelectric Efficiency

Te-Hsien Wang^1,2*

¹Institute of Nanoscience, National Chung Hsing University, Taichung, Taiwan
²Department of Physics, National Chung Hsing University, Taichung, Taiwan

* Presenter:Te-Hsien Wang, email:thwang@phys.nchu.edu.tw

Thermoelectric (TE) materials, which enable the direct conversion of heat into electricity, have gained significant attention due to their potential applications in energy harvesting and waste heat recovery. This study investigates the impact of low-dimensional electronic structures, particularly two- and one-dimensional characteristics, on the TE properties of bulk materials. Through first-principles calculations, we find that these materials exhibit low-dimensional-like behavior in their electronic structures, leading to significant improvements in effective band degeneracy and TE performance. The highly anisotropic band structures, with near-flat dispersion in certain crystallographic directions and strong dispersion in others, result in density of states that mimic those of nanostructures but avoid deterioration caused by subband splitting. These findings highlight the potential for optimizing low-dimensional electronic features in bulk materials to achieve high TE figures of merit (zT), offering promising insights for the development of advanced TE materials for efficient energy conversion.

Keywords: thermoelectric, low-dimensional electronic structures, bulk materials