rGO/Ag0.005Sn0.995Se热电复合材料的制备及性能研究

Preparation and Properties of rGO/Ag0.005Sn0.995Se Thermoelectric Composites

为了实现石墨烯纳米相在基体中的均匀分散,提高多晶SnSe的热电性能,本文首先利用熔炼法合成了多晶Ag0.005Sn0.995Se材料,然后采用液相沉淀法实现了Ag0.005Sn0.995Se与氧化石墨烯(GO)均匀复合,再经过氢气还原和SPS烧结制备得到rGO/Ag0.005Sn0.995Se复合材料。研究结果表明,复合rGO显著提高了载流子迁移率,电导率由基体的33.64S/cm提高到39.29S/cm。同时第二相rGO的引入,增加了晶界数量,增强了声子散射,降低了热导率。当复合rGO量为0.50wt%时,在垂直热压方向上获得了最高的ZT值0.73(773K)。

In order to improve the thermoelectric properties of the polycrystalline SnSe by dispersing the graphene nanophase in the matrix uniformly,polycrystalline Ag0.005Sn0.995Se material was synthesized by melting method,then graphene oxide (GO) was uniformly dispersed in the Ag0.005Sn0.995Se matrix via liquid precipitation method,finally the rGO/Ag0.005Sn0.995Se composite material was prepared by hydrogen reduction and SPS. The results show that the addition of rGO can significantly enhance the carrier mobility,so the electrical conductivity increased from 33.64 S/cm to 39.39 S/cm. At the same time,the introduction of the second phase rGO increased the number of grain boundaries and enhanced phonon scattering,leading to the reduced thermal conductivity. The highest ZT value of 0.73(773 K) was obtained along perpendicular to the pressing direction for 0.50wt% rGO/Ag0.005Sn0.995Se composite.