The effect of cesium dopant on APCVD graphene coating on copper
Samira Naghdi, Katarina Nešović, G. Sánchez‐Arriaga, Hyun Yong Song, Sung Wng Kim, Kyong Yop Rhee, Vesna Mišković‐Stanković
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 Cs3d5/2 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.