Continuous epitaxy of single-crystal graphite films by isothermal carbon diffusion through nickel

• Published in: Nature nanotechnology Vol. 17; no. 12; pp. 1258 - 1264
• Main Authors: Zhang, Zhibin, Ding, Mingchao, Cheng, Ting, Qiao, Ruixi, Zhao, Mengze, Luo, Mingyan, Wang, Enze, Sun, Yufei, Zhang, Shuai, Li, Xingguang, Zhang, Zhihong, Mao, Hancheng, Liu, Fang, Fu, Ying, Liu, Kehai, Zou, Dingxin, Liu, Can, Wu, Muhong, Fan, Chuanlin, Zhu, Qingshan, Wang, Xinqiang, Gao, Peng, Li, Qunyang, Liu, Kai, Zhang, Yuanbo, Bai, Xuedong, Yu, Dapeng, Ding, Feng, Wang, Enge, Liu, Kaihui
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-12-2022; Nature Publishing Group
• Subjects: 140/133; 639/301/357/1018; 639/925/918; Bonding strength; Carbon; Chemical bonds; Chemical potential; Chemical precipitation; Chemical synthesis; Chemistry and Materials Science; Crystal growth; Diffusion; Dissolution; Epitaxial growth; Epitaxy; Flat surfaces; Foils; Graphene; Graphite; Letter; Materials Science; Mechanical properties; Modulus of elasticity; Multilayers; Nanotechnology; Nanotechnology and Microengineering; Nickel; Physical properties; Potential gradient; Single crystals; Stacking; Thermal conductivity; Thick films; Thickness
• ISSN: 1748-3387; 1748-3395
• DOI: 10.1038/s41565-022-01230-0

Multilayer van der Waals (vdW) film materials have attracted extensive interest from the perspective of both fundamental research
1
–
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and technology
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–
7
. However, the synthesis of large, thick, single-crystal vdW materials remains a great challenge because the lack of out-of-plane chemical bonds weakens the epitaxial relationship between neighbouring layers
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–
31
. Here we report the continuous epitaxial growth of single-crystal graphite films with thickness up to 100,000 layers on high-index, single-crystal nickel (Ni) foils. Our epitaxial graphite films demonstrate high single crystallinity, including an ultra-flat surface, centimetre-size single-crystal domains and a perfect AB-stacking structure. The exfoliated graphene shows excellent physical properties, such as a high thermal conductivity of ~2,880 W m
−1
 K
−1
, intrinsic Young’s modulus of ~1.0 TPa and low doping density of ~2.2 × 10
10
 cm
−2
. The growth of each single-crystal graphene layer is realized by step edge-guided epitaxy on a high-index Ni surface, and continuous growth is enabled by the isothermal dissolution–diffusion–precipitation of carbon atoms driven by a chemical potential gradient between the two Ni surfaces. The isothermal growth enables the layers to grow at optimal conditions, without stacking disorders or stress gradients in the final graphite. Our findings provide a facile and scalable avenue for the synthesis of high-quality, thick vdW films for various applications.
Isothermal dissolution–diffusion–precipitation of carbon drives continuous epitaxial growth of single-crystal multilayer graphene.