Journal Article

Flexible layer-structured Bi2Te3 thermoelectric on a carbon nanotube scaffold

Qiu, Jianhang, Gao, Ning, Tan, Jun, Dong-Ming, Sun, Wang, Dong, Jiang, Xin, Peng-Xiang, Hou, Xing-Qiu, Chen, Jiang, Song, Jin, Qun, Zhao, Yang, Dai-Ming, Tang, Tai, Kaiping, Hui-Ming, Cheng, Liu, Chang

2019

Overview

Inorganic chalcogenides are traditional high-performance thermoelectric materials. However, they suffer from intrinsic brittleness and it is very difficult to obtain materials with both high thermoelectric ability and good flexibility. Here, we report a flexible thermoelectric material comprising highly ordered Bi2Te3 nanocrystals anchored on a single-walled carbon nanotube (SWCNT) network, where a crystallographic relationship exists between the Bi2Te3 <\\[\\bar{1}2\\bar{1}0\\]> orientation and SWCNT bundle axis. This material has a power factor of ~1,600 μW m−1 K−2 at room temperature, decreasing to 1,100 μW m−1 K−2 at 473 K. With a low in-plane lattice thermal conductivity of 0.26 ± 0.03 W m−1 K−1, a maximum thermoelectric figure of merit (ZT) of 0.89 at room temperature is achieved, originating from a strong phonon scattering effect. The origin of the excellent flexibility and thermoelectric performance of the Bi2Te3–SWCNT material is attributed, by experimental and computational evidence, to its crystal orientation, interface and nanopore structure. Our results provide insight into the design and fabrication of high-performance flexible thermoelectric materials.

• Publisher: Nature Publishing Group
• Subject: Bismuth tellurides / Carbon / Crystal structure / Crystallography / Fabrication / Figure of merit / Flexibility / Heat conductivity / Laboratories / Materials science / Nanocrystals / Porosity / Power factor / Single wall carbon nanotubes / Thermal conductivity / Thermoelectric materials