(Invited) Nanostructured Thermoelectric Materials Prepared from Bi2Se3 and Bi2Te3 Nanoplates for Enhanced Thermoelectric Properties

The development of high-performance thermoelectric (TE) materials has been a challenging issue to realize power generation or eco-friendly refrigerating systems. In particular, TE materials based on the nanomaterials such as nanoparticles, nanowires, and nanoplates have been expected to enhance the TE efficiency. Herein, we introduced the solution-based synthesis of 2D Bismuth chalcogenides with the ultra-thin thickness Bismuth chalcogenides (Bi 2 Q 3 , Q = Se, Te), which is known the best TE materials at room temperature, are layer-structured materials arranged in planar quintuple layers (QLs, with each QL approximately 1 nm thick). Each QL consists of five consecutive covalently bound atomic sheets (Q-Bi-Q-Bi-Q), and neighboring QLs are stacked by weak van der Waals interactions along the c-axis. It is well known that introducing nanoscale grains and interfaces in nanostructured bulk composites increases the phonon scattering and filters low energy charge carriers without any considerable reduction in electronic conductivity. This enhanced phonon scattering leads to a higher thermoelectric figure of merit (ZT). One promising approach for achieving uniformly distributed nanoscale interfaces is to use laterally heterostructured nanoplates as building blocks. In this study, thermoelectric properties of pelletized bulk samples was systemically investigated, which are made of the (Bi 2 Se 3 ) x @(Bi 2 Te 3 ) 1-x