Toward Direct Growth of Ultra-Flat Graphene

摘要

The elimination of wrinkles has become a research hotspot in the realm ofthe chemical vapor deposition growth of graphene, and there have beenreliable routes developed for the scenario of catalytic synthesis on metals.Nonetheless, the transfer-free growth of graphene over insulating substratesaffording ultra-flatness remains a puzzle. Here, the authors report the directpreparation of ultra-flat graphene on an economical quartz glass substrate ata wafer level, without any wrinkles and metallic impurities, is reported. Densityfunctional theory calculations are employed to establish that grapheneadlayer is prone to generate in the presence of textured particulates. In parallel,a critical temperature regime (1443–1453 K), is identified within whichgraphene adlayer-restrained forming and substrate in-situ flattening couldsimultaneously occur. The thus-obtained graphene enables the atomicallysmooth growth of a GaN film with (001) single-crystallinity over the amorphoussubstrate. This technique is particularly attractive in the context ofcost-effective integration of emerging III-nitrides toward exciting applications.