Fundamentals of the temperature-dependent electrical conductivity of a 3D carbon foam-Aerographite
Fundamentals of the temperature-dependent electrical conductivity of a 3D carbon foam-Aerographite
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DOI：
10.1016/j.synthmet.2017.12.006
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发表时间：
2018-01-01
期刊：
影响因子：
4.4
通讯作者：
Fiedler, B.
中科院分区：
文献类型：
--
作者：
Marx, J.;Brouschkin, A.;Fiedler, B.
航空石墨是一种具有中空四足形态的3D互连碳泡沫。航空石墨的性能，特别是导电性，强烈地依赖于壁厚、石墨化度和环境温度。定制的碳结构如壁厚（层数）和石墨化状态决定了碳泡沫的电性能。气相石墨的壁厚可以通过相对于合成时间逐步减少牺牲模板的固体臂来控制，其中壁厚可以容易地实现在3和22 nm之间。壁厚的减小导致未处理的石墨的导电性降低。退火后的石墨导电率随壁厚的减小而增大。通过扫描电子显微镜（SEM）、透射电子显微镜（TEM）和拉曼光谱分析了石墨的形貌。此外，测量电导率对温度的依赖性，并基于此计算带隙能量。结果表明，航空石墨显示出金属导电行为，通过进一步的高温处理可以改变其半导体性质。
Aerographite is a 3D interconnected carbon foam with a hollow tetrapodal morphology. The properties of Aerographite, especially the electrical conductivity, are strongly dependent on the wall thickness, the degree of graphitization and the ambient temperature. The tailored-carbon-structures like wall thickness (number of layer) and state of graphitization determine the electrical properties of the carbon foam. The wall thickness of Aerographite can be controlled by a stepwise reduction of solid arms of sacrificial template with respect to synthesis time, in which wall thicknesses between 3 and 22 nm can be easily achieved. The decreasing of the wall thickness leads to a reduced electrical conductivity of untreated Aerographite. Contrary, the conductivity of annealed Aerographite increased with reducing of the wall thicknesses. The morphology of Aerographite has been analyzed via scanning electron (SEM), transmission electron (TEM) microscopy and Raman spectroscopy. Furthermore, the dependency of the electrical conductivity on the temperature is measured and based on this the band gap energy is calculated. As a result, Aerographite shows a metallic conductive behaviour which can be changed semiconducting nature by further high temperature treatment.