Premelted-Substrate-Promoted Selective Etching Strategy Realizing CVD Growth of High-Quality Graphene on Dielectric Substrates

Direct chemical vapor deposition growth of high-quality graphene on dielectric substrates is a great challenge. Graphene growth on dielectrics always suffers from the issues of a high nucleation density and poor quality. Herein, a premelted-substrate-promoted selective etching (PSE) strategy was proposed. The premelted substrate can promote charge transfer from the substrate to the nuclei near graphene domains, thus facilitating the reaction between the CO₂ etchant and the nuclei. Consequently, the PSE strategy can realize selective etching of nuclei formed near graphene domains to evolve high-quality graphene with a uniform domain size of ∼1 μm and an I_D/I_G ratio of ∼0.13 on glass fiber, achieving the largest domain size and the lowest defect density in graphene grown on a noncatalytic substrate without metal assistance. The largely improved quality of graphene significantly increases the electrical conductivity by 3 times and improves the working life by 7 times when applied as an electric heater compared with that fabricated without the PSE strategy.