Scaled‐Up Graphene Growth Through Chemical Vapor Deposition Over Large‐Area Liquid Cu Catalysts

Abstract This study scales up the chemical vapor deposition (CVD) process for graphene growth using CH₄ and H₂ mixtures on large molten Cu substrates using a liquid metal catalyst (LMCat) reactor. In situ optical microscopy and ex situ Raman spectroscopy reveal key differences from previous studies on smaller molten Cu surfaces. Graphene grown on large molten Cu exhibits improved quality and uniformity at low [CH₄]/[H₂] ratios. A shift in the growth mechanism is observed: at low [CH₄]/[H₂], single‐front growth yields high‐quality graphene, whereas higher ratios cause multiple nuclei to merge, forming a nucleation‐flow‐merger pattern. Raman spectroscopy confirms uniform graphene quality at low [CH₄]/[H₂]. At intermediate [CH₄]/[H₂], few‐layer graphene grows uniformly on larger Cu substrates. Finite element analysis using COMSOL Multiphysics shows that efficient heating of reaction gases by molten Cu enhances graphene growth. An empirical model, developed from experimental data, reliably predicts the fastest graphene growth on large liquid Cu substrates. These findings address critical challenges and advance the feasibility of continuous, industrial‐scale graphene production using molten metal catalysts.