ZOU Jiazhen ¹，CHEN Xinqi ¹，FAN Yuchi ²， WANG Lianjun ¹，GU Shijia ²
(1. State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620, China; 2. Institute of Functional Materials, Donghua University, Shanghai 201620, China)

Abstract: In this paper Bi₂Te₃ nanoplates were synthesized via solvothermal method, and then densified by spark plasma sintering (SPS). The influence of the surfactant (polyvinyl pyrrolidone, PVP) on the morphology and size of Bi₂Te₃ powder as well as the thermoelectric properties of the bulk samples was investigated by using X-ray diffraction, scanning electron microscope, transmission electron microscope and thermoelectric test system, and laser flash analysis. The results show that the synthesized Bi₂Te₃ is of hexagonal single crystal nanoplates with the lateral size of 800 nm and the thickness of 20 nm. After sintering by SPS, it is found that the sample prepared with PVP has much lower thermal conductivity compared to the sample prepared without PVP, which leads to high ZT values with a maximum of 0.64 at 450 K.

Key words: solvothermal synthesis; nanoplate; Bi₂Te₃; PVP; thermoelectric properties