Open-atmosphere flame synthesis of monolayer graphene

An open-atmosphere, unconfined setup comprising a novel multiple inverse-diffusion flame (m-IDF) burner modified with extended precursor tubes is employed to synthesize graphene on substrates. Growth conditions of mono-, bi-, and few-layer (MLG, BLG, FLG, respectively) are investigated, systematic variation parameters such as substrate temperature, methane-to-hydrogen volume flow rate ratio (JCH4:JH2), growth duration, post-flame profiles, material, species (e.g., CH4, C2H2, C2H4), in-situ post-growth hydrogen annealing. Graphene copper observed for wide range temperatures from 850 °C 1000 °C, high-quality BLG created at temperature JCH4:JH2 1:100 5 min duration. A sequential annealing treatment, where the hydrocarbon terminated but m-IDFs maintained, found be effective etching adlayers graphene. As such, reduced MLG by increasing duration 10 min. In-situ gas-phase Raman measurements characterize evolution in synthesis field. CH2 determined main carbon needed near form our system.