Thermoelectric Properties of (Graphene/PbTe) Composites

• Main Authors: Chi-Wei Tsai, 蔡既瑋
• Other Authors: Ching-Cherng Wu
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/5mw467

碩士 === 國立東華大學 === 材料科學與工程學系 === 107 === In this study, Graphene/PbTe composites with various Graphene composition 0、0.1、1、3、5 and 10wt% were prepared by cold pressing and annealing. The composition and microstructure of these composites were examined by optical microscope(OM), X-ray diffraction(XRD), field emission scanning electron microscope(FE-SEM) and energy dispersive X-ray spectroscopy(EDS). The thermoelectric properties for these composites were studied by means of thermal and electrical transport measurement in the temperature range between 60 K and 300 K. The temperature dependence of the thermoelectric properties of Graphene/PbTe composites were discussed. The electrical resistivity of Graphene/PbTe composites are decreased with increasing temperature showing semiconducting properties. And the electrical resistivity also decreased with increasing Graphene content. The lowest value of resistivity is 0.006ohm-cm for the PbTe sample with 10wt% Graphene at 300K . The seebeck coefficient of all the Graphene/PbTe composites are positive , showing p-type conduct and the highest seebeck coefficient(306uV/K) are obtained at 300K for Graphene/PbTe composites with 0.1wt% Graphene . The thermal conductivity of these composites decreased with increasing temperature. The Graphene/PbTe composite with 0.1wt Graphene exhibits the maximum ZT=0.03 at 300 K which was attributed to its highest seebeck coefficient and lowest thermal conductivity. The thermoelectric properties of Graphene/PbTe composites were not enhanced due to their low Seebeck coefficient and high thermal conductivity, although the resistivity was significantly improved after the addition of graphene.