• Hong, Byung Hee
• Moon, Joonhee
• Suh, Yeonjoon
• Kim, Dong Jin
• Park, Mina
• Jeong, Heejeong
• Lee, Chang-Won
• Jo, Insu
• Woo, Yunsung

Abstract

<jats:title>Abstract</jats:title><jats:p>For the industrial quality control (QC) of the chemical vapor deposition (CVD) graphene, it is essential to develop a method to screen out unsatisfactory graphene films as efficiently as possible. However, previously proposed methods based on Raman spectroscopy or optical imaging after chemical etching are unable to provide non-invasive and fast analysis of large-area graphene films as grown on Cu foil substrates. Here we report that the reflection mode of confocal laser scanning microscopy (CLSM) provides a high-contrast image of graphene on Cu, enabling the real-time evaluation of the coverage and quality of graphene. The reflectance contrast, <jats:italic>Rc</jats:italic>, was found to be dependent on the incident laser wavelength, of which the maximum was obtained at 405 nm. In addition, <jats:italic>Rc</jats:italic> decreases with increasing defect density of graphene. The dependence of <jats:italic>Rc</jats:italic> on the graphene’s quality and laser wavelengths were explained by the tight-binding model calculation based on the Fresnel’s interference formula. Thus, we believe that the reflection mode CLSM would be a very powerful quality-assessment tool for the mass production of CVD graphene films grown on Cu.</jats:p>

Topics

• density
• impedance spectroscopy
• etching
• defect
• Raman spectroscopy
• chemical vapor deposition
• confocal laser scanning microscopy