DFT‐Assisted Approach to Low‐Temperature Graphene Growth on Sapphire

Controlling the direct growth of 2D materials onto dielectric substrates is considered as a key requirement for integrating these ultrathin functional materials into existing technology platforms. Here, a combined experimental and theoretical approach is presented to unravel the mechanism of low‐temperature graphene growth on sapphire, a dielectric substrate widely used in the semiconductor industry. A clear dependence of the graphene growth rate on the crystal facet is found, with the highest growth rate for a ‐plane and ca ‐plane, and the lowest for r ‐plane sapphire. Density functional theory calculations reveal that the coordination environment of surface oxygen ions governs carbon adsorption energetics: lower coordinated oxygen sites on the a ‐plane markedly enhance carbon atom binding, driving nucleation and growth, while higher coordinated oxygen sites on the r‐ plane hinder adsorption and growth. Guided by these insights, it is demonstrated that tailoring substrate termination yields controllable graphene formation at temperatures as low as 670 °C and sheet resistances down to 1.65 kΩ □ −1 . This approach may establish a universal design principle to guide low‐temperature growth of 2D materials on non‐catalytic dielectrics.