超薄硒化铋片状粉体烧结与热电性能的研究

Study on Sintering and Thermoelectric Properties of Ultra-thin Bismuth Selenide Flake Powder

采用水热法合成二维超薄纳米片状硒化铋,进一步利用放电等离子烧结制备出块状硒化铋陶瓷。同时,研究了烧结温度、时间和压力对陶瓷致密度的影响。以X射线衍射、X射线光电子能谱、扫描电子显微镜对样品组成、晶体结构与组织进行了表征,分析了最佳烧结条件下获得硒化铋陶瓷的热电性能。结果表明以二维超薄片状硒化铋为原始粉体,有利于片层状晶体颗粒生长,烧结后获得各向异性微观组织结构。在温度500℃、保温1 h以及压力40 MP烧结条件下,硒化铋陶瓷微观组织呈致密二维片状结构,同时在300℃时其电导率956.538S/m,塞贝克系数最大为9.61×10^(-5)V/K,功率因子达到8.83×10^(-6)W/m K^(2)。

In this paper, two-dimensional ultra-thin Bi2Se3nano-sheets was synthesized by hydrothermal method, and bulk Bi2Se3ceramics were prepared by spark plasma sintering. At the same time, the effects of sintering temperature, time and pressure on the density of ceramics were studied. The obtained samples were characterized by X-ray diffraction, X-ray photoelectron spectroscope and scanning electron microscope.The thermoelectric properties of the Bi2Se3ceramics prepared under the optimum sintering conditions were also analyzed. The results show that using two-dimensional ultra-thin Bi2Se3nano-sheets as starting powder was beneficial to the growth of lamellar crystal particles, and form anisotropic microstructure after sintering. The microstructure of bismuth selenide ceramics showed a compact two-dimensional sheet structure under the sintering conditions of 500 ℃, 1h holding temperature and 40 MP pressure. Meanwhile the electric conductivity was 956.538 S/m, the Seebeck coefficient was 9.61×10^(-5)V/K, and the power factor was 8.83×10^(-6)W/mK^(2) at 300 ℃.