Epitaxiai graphene is synthesized by silicon sublimation from the Si-terminated 6H SiC substrate. The effects of graphitization temperature on the thickness and surface morphology of epitaxial graphene are investigate...Epitaxiai graphene is synthesized by silicon sublimation from the Si-terminated 6H SiC substrate. The effects of graphitization temperature on the thickness and surface morphology of epitaxial graphene are investigated. X-ray photoelectron spectroscopy spectra and atomic force microscopy images reveal that the epitaxial graphene thickness increases and the epitaxial graphene roughness decreases with the increase in graphitization temperature. This means that the thickness and roughness of epitaxial graphene films can be modulated by varying the graphitization temperature. In addition, the electrical properties of epitaxial graphene film are also investigated by Hall effect measurement.展开更多
Flexible graphite film(FGF),as a traditional interface heat dissipation material,has high anisotropy.It is a challenge to enhance both in-plane and through-plane thermal conductivity of FGF.For this reason,the effects...Flexible graphite film(FGF),as a traditional interface heat dissipation material,has high anisotropy.It is a challenge to enhance both in-plane and through-plane thermal conductivity of FGF.For this reason,the effects of oxygen content,layer spacing,density and particle size on the in-plane and through-plane thermal conductivity of FGF were studied by both molecular simulation and experimental investigation.The simulation results indicate that the ways to improve the thermal conductivity of FGF include reducing oxygen content and layer spacing,increasing the density and matching the size of graphite sheets.The FGF prepared from room temperature exfoliated graphite(RTFGF)has a wide range of adjustable density(1.3–2.0 g/cm^(3))and thickness(50–400μm).The thermal conductivity of the RTFGF is significantly improved after heat treatment owing to reduced oxygen content and layer spacing,which is consistent with the simulation results.Moreover,RTFGF with both high in-plane(518 W·m^(-1)·K^(-1))and through-plane(7.2 W·m^(-1)·K^(-1))thermal conductivity can be obtained by particle size matching of graphite.展开更多
基金supported by the Program for New Century Excellent Talents in University (Grant No. NCET-10-0291)the Fundamental Research Funds for the Central Universities (Grant Nos. ZYGX2009X005 and ZYGX2010J031)+1 种基金the Startup Research Project of University of Electronic Science and Technology of China (Grant No.Y02002010301041)the National Natural Science Foundation of China (Grant Nos. 50832007 and 11074285)
文摘Epitaxiai graphene is synthesized by silicon sublimation from the Si-terminated 6H SiC substrate. The effects of graphitization temperature on the thickness and surface morphology of epitaxial graphene are investigated. X-ray photoelectron spectroscopy spectra and atomic force microscopy images reveal that the epitaxial graphene thickness increases and the epitaxial graphene roughness decreases with the increase in graphitization temperature. This means that the thickness and roughness of epitaxial graphene films can be modulated by varying the graphitization temperature. In addition, the electrical properties of epitaxial graphene film are also investigated by Hall effect measurement.
基金We would like to acknowledge the support provided by National Key R&D Program of China(2021YFC2902904).
文摘Flexible graphite film(FGF),as a traditional interface heat dissipation material,has high anisotropy.It is a challenge to enhance both in-plane and through-plane thermal conductivity of FGF.For this reason,the effects of oxygen content,layer spacing,density and particle size on the in-plane and through-plane thermal conductivity of FGF were studied by both molecular simulation and experimental investigation.The simulation results indicate that the ways to improve the thermal conductivity of FGF include reducing oxygen content and layer spacing,increasing the density and matching the size of graphite sheets.The FGF prepared from room temperature exfoliated graphite(RTFGF)has a wide range of adjustable density(1.3–2.0 g/cm^(3))and thickness(50–400μm).The thermal conductivity of the RTFGF is significantly improved after heat treatment owing to reduced oxygen content and layer spacing,which is consistent with the simulation results.Moreover,RTFGF with both high in-plane(518 W·m^(-1)·K^(-1))and through-plane(7.2 W·m^(-1)·K^(-1))thermal conductivity can be obtained by particle size matching of graphite.
