Preparation of n-type Bi2Te3 Thermoelectric Materials by Different Surfactants 不同表面活性剂制备n型Bi2Te3热电材料

N-type BiTe nano-powders were prepared by hydrothermal method, using [P123(polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer), PVP (polyvinylpyrrolidone), and EDTA (ethylene diamine tetraacetic acid)] as template agents. Moreover, the n-type BiTethermoelectric bulk samples were prepared by Spark Plasma Sintering technology (SPS). The phase, morphology and thermoelectric properties of the prepared samples were characterized by XRD, SEM, ZEM-3 and laser thermal conductivity. The results show that most of the BiTe nanoparticles prepared by the three template agents are flake-shaped. Among them, the PVP-made nanosheets are the most regular, the EDTA-made nanosheets are not uniform in size, and the P123-made nanosheets are mixed with rod-like and agglomerated spherical shapes; XRD patterns show that the as-prepared nano-powders are all pure BiTe phase without other impurities. The research on the thermoelectric properties of bulk samples found that:due to the unique layered structure of BiTe, which would affect the carrier and phonon transmission, the ZT value of the prepared bulk sample perpendicular to the pressure direction was larger than that parallel to the pressure direction. The BiTe sample prepared by the PVP template presented the best thermoelectric performance and the ZT value reached 0.33 at a temperature of 480 K.