Radical-mediated epitaxial growth of wafer-scale single-crystal graphene at room temperature

초록

The synthesis of wafer-scale single-crystalline graphene (SCG) typically requires high temperatures (>750 degrees C) to overcome kinetic barriers associated with precursor activation and domain coalescence. Here, we report a fundamentally different growth paradigm that enables the room-temperature formation of SCG via pre-activated benzene radicals. By generating reactive phenyl species prior to surface adsorption and employing a hydrogen-enriched Cu(111) substrate, we bypass the rate-limiting dehydrogenation steps and promote spontaneous coupling reactions at ambient conditions. This strategy yields epitaxially aligned graphene domains that seamlessly merge into a wafer-scale single crystal without adlayers or wrinkles. Density functional theory and molecular dynamics simulations reveal that hydrogen incorporation into Cu enhances surface electrophilicity and lowers the activation barrier for radical coupling. The resulting graphene exhibits high crystallinity and carrier mobility comparable to high-temperature-grown counterparts. This work establishes a molecularly engineered route for low-energy synthesis of two-dimensional materials and provides a general framework for radical-mediated crystal growth.

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