Atomic-Scale Tuning of Graphene/Cubic SiC Schottky Junction for Stable Low-Bias Photoelectrochemical Solar-to-Fuel Conversion

Abstract

Engineering tunable graphene-semiconductor interfaces while simultaneously preserving the superior properties of graphene is critical to the graphene-based devices for electronic, optoelectronic, biomedical and photoelectrochemical applications. Here, we demonstrate this challenge can be surmounted by constructing a novel atomic Schottky junction via epitaxial growth of high-quality and uniform graphene on cubic SiC (3C-SiC). By tailoring the graphene layers, the herein-described junction structure exhibits an atomic-scale tunable Schottky junction with an inherent built-in electric field, making it a perfect prototype to systematically comprehend the interfacial electronic properties and transport mechanisms. As a proof-of-concept study, the atomic-scale tuned Schottky-junction is demonstrated to promote both the separation and transport of charge carriers in a typical photoelectrochemical system for solar-to-fuel conversion under low bias. Simultaneously, the as-grown monolayer graphene with an extremely high conductivity protects the surface of 3C-SiC from photocorrosion and energetically delivers charge carriers to the loaded cocatalyst, achieving a synergetic enhancement of the catalytic stability and efficiency.