Low-temperature synthesis of vertically aligned graphene through microwave-assisted chemical vapour deposition
Low-temperature synthesis of vertically aligned graphene through microwave-assisted chemical vapour deposition
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DOI：
10.1016/j.tsf.2021.138801
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发表时间：
2021-07-12
期刊：
影响因子：
2.1
通讯作者：
Kelly, Peter J.
中科院分区：
文献类型：
--
作者：
Kulczyk-Malecka, Justyna;dos Santos, Isabella V. J.;Kelly, Peter J.
垂直排列的石墨烯（VG）的固有性质，例如与惰性基底位点相比暴露的活性边缘位点的高比率、非堆叠形态和大的表面积与体积比，使其适用于许多先进技术，例如传感器、柔性电子器件和燃料电池。等离子体增强化学气相沉积已经成为一种有前途的技术，可以在比常规化学气相沉积（CVD）工艺更低的温度下合成石墨烯，从而更好地控制沉积参数以定制石墨烯特性。本研究提出了一种具有成本效益的，可扩展的，在低温下一步合成高品质VG的方法。在微波（MW）辅助CVD反应器中合成样品，该反应器允许在作为载气的Ar中分解CH4和H2气体混合物，并且VG直接生长到Si晶片衬底上而无需向衬底施加任何额外的热。沉积条件，如微波功率，气体比例，和基板等离子体分离进行了优化，以定制的形态，生长速度和电化学性能的VG。物理化学分析表明，所制造的VG由高质量的垂直排列的sp2石墨烯组成，而循环伏安分析证实，该结构具有电化学活性，并表现出准可逆过程的典型特征。
The intrinsic properties of vertically aligned graphene (VG), such as a high ratio of exposed active edge sites compared to inert basal sites, non-stacking morphology and large surface-to-volume ratio make it applicable to numerous advanced technologies such as sensors, flexible electronics and fuel cells. Plasma-enhanced chemical vapour deposition has emerged as a promising technique to synthesise graphene at lower temperatures than a conventional chemical vapour deposition (CVD) process, providing a better control over the deposition parameters to tailor graphene properties. This study presents a cost effective, scalable, single step synthesis of a high quality VG at low temperatures. The samples were synthesised in a microwave (MW) assisted CVD reactor, which allowed for the decomposition of CH4 and H2 gas mixtures in Ar as a carrier gas, and VG growth directly onto Si wafer substrates without any additional heat applied to the substrate. Deposition conditions, such as MW power, gas ratio, and substrate-toplasma separation were optimized to tailor the morphology, growth rate and electrochemical performance of the VG. The physiochemical analysis revealed that the fabricated VG consisted of high quality vertically aligned sp2 graphene, whilst a cyclic voltammetry analysis confirmed that the structures are electrochemically active and demonstrate a typical characteristics of quasi-reversible processes.