We investigate the graphene nucleation site in real space using radiation-mode optical microscopy (Rad-OM), which we have developed for the real-Time observation of the graphene growth in chemical vapor deposition (CVD) conditions. We found the bright spot in the Rad-OM image worked as a nucleation site through continuous observation of a Cu substrate from pretreatment to graphene growth. The bright spot, considered as a C impurity, was effectively removed by Ar bombardment, which significantly reduced the nucleation density. The present result directly elucidates the role of C impurities and provides a means to grow single-crystalline and large-Area graphene via CVD.
ASJC Scopus subject areas
- Physics and Astronomy(all)