Xu Shichen, Cheng Ting, Yan Qingwei, Shen Chao, Yu Yue, Lin Cheng-Te, Ding Feng, Zhang Jin
Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China.
Beijing Graphene Institute (BGI), Beijing, 100095, P. R. China.
Adv Sci (Weinh). 2022 May;9(15):e2200737. doi: 10.1002/advs.202200737. Epub 2022 Mar 24.
With the continuous progress in electronic devices, thermal interface materials (TIMs) are urgently needed for the fabrication of integrated circuits with high reliability and performance. Graphene as a wonderful additive is often added into polymer to build composite TIMs. However, owing to the lack of a specific design of the graphene skeleton, thermal conductivity of graphene-based composite TIMs is not significantly improved. Here a chloroform-assisted method for rapid growth of vertical graphene (VG) arrays in electric field-assisted plasma enhanced chemical vapor deposition (PECVD) system is reported. Under the optimum intensity and direction of electric field and by introducing the highly electronegative chlorine into the reactor, the record growth rate of 11.5 µm h is achieved and VG with a height of 100 µm is successfully synthesized. The theoretical study for the first time reveals that the introduction of chlorine accelerates the decomposition of methanol and thus promotes the VG growth in PECVD. Finally, as an excellent filler framework in polymer matrix, VG arrays are used to construct a free-standing composite TIM, which yields a high vertical thermal conductivity of 34.2 W m K at the graphene loading of 8.6 wt% and shows excellent cooling effect in interfacial thermal dissipation of light emitting diode.
随着电子设备的不断进步，制造具有高可靠性和高性能的集成电路迫切需要热界面材料（TIMs）。石墨烯作为一种优异的添加剂，常被添加到聚合物中以制备复合热界面材料。然而，由于石墨烯骨架缺乏特定设计，基于石墨烯的复合热界面材料的热导率并未得到显著提高。本文报道了一种在电场辅助等离子体增强化学气相沉积（PECVD）系统中通过氯仿辅助快速生长垂直石墨烯（VG）阵列的方法。在最佳电场强度和方向下，通过将高电负性的氯引入反应腔，实现了11.5 µm/h的创纪录生长速率，并成功合成了高度为100 µm的垂直石墨烯。理论研究首次揭示，氯的引入加速了甲醇的分解，从而促进了PECVD中垂直石墨烯的生长。最后，作为聚合物基体中优异的填料骨架，垂直石墨烯阵列被用于构建独立的复合热界面材料，在石墨烯负载量为8.6 wt%时，其垂直热导率高达34.2 W m⁻¹ K⁻¹，并在发光二极管的界面热耗散中表现出优异的散热效果。
