Synthesis of Domain-Controlled Graphene by Sequential Heating and Its Thermoelectric Properties

Abstract

Graphene, which has superior mechanical, electrical, optical and thermal properties, has attracted many researchers since it was firstly discovered. There are many efforts to utilize graphene as a thermoelectric material which is highly prospective in environment friendly energy field. In order to do that, reducing thermal conductivity of graphene is necessary. In this study, we used strategy of subdomain formation within graphene which can effectively drop the thermal conductivity of graphene without affecting electrical conductivity. We synthesized graphene including nano sized subdomain via Mobile Hot Wire CVD system that enables sequential heating of sample, and confirmed the formation of subdomains within the graphene via TEM analysis. After then, we measured Seebeck coefficient, electrical conductivity of graphene respectively and calculated power factor value. Hotwire scanned graphene shows 1.25 times higher power factor than graphene synthesized via conventional CVD system. It is expected that further measurement of thermal conductivity can verify suitability of hotwire graphene as a thermoelectric material.