The effect of cesium dopant on APCVD graphene coating on copper

Abstract

This study reports in-situ cesium-doped graphene (G/Cs) coating obtained by introducing Cs2CO3 into the atmospheric pressure chemical vapor deposition (APCVD) furnace during graphene deposition on copper. The successful Cs-doping of the graphene coating was confirmed via X-ray photoelectron spectroscopy (XPS). As compared to the spectra of pure graphene coating, the XPS spectra of the G/Cs coating revealed a shift of the C1s and Cs3d(5/2) peaks to higher and lower binding energies, respectively; thus, implying the n-type character of the doping and indicating a charge transfer between Cs and graphene. Raman results show that a pure graphene coating is composed of fewer layers, fewer defects, and larger domain size than the G/Cs coating. Ultraviolet photoelectron spectroscopy was utilized to study the work function of graphene and the G/Cs and revealed that doping graphene with Cs dopants reduced the work function of graphene by 1.2 eV. Electrochemical testing during 15-day immersion in 0.1 M NaCl indicated the destructive effect of the G/Cs coating on the Cu substrate. The results showed that the G/Cs coating exhibits a higher corrosion rate and lower corrosion resistance than even the bare metal itself.