Transfer‐Free Quasi‐Suspended Graphene Grown on a Si Wafer

Abstract The direct growth of graphene affording wafer‐scale uniformity on insulators is paramount to electronic and optoelectronic applications; however, it remains a challenge to date, because it entails an entirely different growth mode than that over metals. Herein, the metal‐catalyst‐free growth of quasi‐suspended graphene on a Si wafer is demonstrated using an interface‐decoupling chemical vapor deposition strategy. The employment of lower‐than‐conventional H 2 dosage and concurrent introduction of methanol during growth can effectively weaken the interaction between the synthesized graphene and the underlying substrate. The growth mode can be thus fine‐tuned, producing a predominantly monolayer graphene film with wafer‐level homogeneity. Graphene thus grown on a 4 inch Si wafer enables the transfer‐free fabrication of high‐performance graphene‐based field‐effect transistor arrays that exhibit almost no shift in the charge neutral point, indicating a quasi‐suspended feature of the graphene. Moreover, a carrier mobility up to 15 000 cm 2 V ‐1 s ‐1 can be attained. This study is anticipated to offer meaningful insights into the synthesis of wafer‐scale high‐quality graphene on dielectrics for practical graphene devices.