Direct Plasma-Enhanced-Chemical-Vapor-Deposition Syntheses of Vertically Oriented Graphene Films on Functional Insulating Substrates for Wide-Range Applications

Graphene has inspired wide-range research interests and practical applications due to its intriguing materials properties and versatile application prospects. Specifically, vertically oriented graphene (VG) constructed by vertically aligned nanosheets emerges as a unique material type, usually achieved through a plasma-enhanced chemical vapor deposition (PECVD) route. The VG films possess abundant exposed active edges, large surface areas, relatively high electrical conductivity, and excellent thermal property in both in-plane and out-of-plane directions. Direct synthesizing of such VG films on various functional substrates enables their transfer-free integrations and direct applications in thermal management, sensing, energy storage and conversion, etc. In this review article, it is planned to showcase the recent advances in direct PECVD growth of VG films on some novel functional insulating substrates (e.g., glass, functional ceramics), mainly in terms of improving the electrical conductivity, enhancing the interfacial adhesion, and graphene growth orientation modulation. Meanwhile, the applications of the PECVD-derived products in various new fields will also be discussed, such as photothermal conversion, switchable windows, light attenuation in photography, transparent heating, and thermal management for high-power devices. Finally, current challenges and future opportunities will also be presented regarding controllable syntheses of high-quality VG films and practical application explorations in different fields.