The effect of cesium dopant on APCVD graphene coating on copper

This study reports in-situ cesium-doped graphene (G/Cs) coating obtained by introducingCs2CO3into the atmospheric pressure chemical vapor deposition (APCVD) furnace dur-ing graphene deposition on copper. The successful Cs-doping of the graphene coating wasconfirmed via X-ray photoelectron spectroscopy (XPS). As compared to the spectra of puregraphene coating, the XPS spectra of the G/Cs coating revealed a shift of the C1s and Cs3d5/2peaks to higher and lower binding energies, respectively; thus, implying the n-type charac-ter of the doping and indicating a charge transfer between Cs and graphene. Raman resultsshow that a pure graphene coating is composed of fewer layers, fewer defects, and largerdomain size than the G/Cs coating. Ultraviolet photoelectron spectroscopy was utilized tostudy the work function of graphene and the G/Cs and revealed that doping graphene withCs dopants reduced the work function of graphene by 1.2 eV. Electrochemical testing during15-day immersion in 0.1 M NaCl indicated the destructive effect of the G/Cs coating on theCu substrate. The results showed that the G/Cs coating exhibits a higher corrosion rate andlower corrosion resistance than even the bare metal itself.This work was supported by Agencia Estatal de Investigación (Ministerio de Ciencia, Innovación y Universidades of Spain, grant No.: ESP2017-82092-ERC (AEI)); SN work is supported by Comunidad de Madrid (Spain) (grant No.: 2018/T2IND/11352); GSA work is supported by the Ministerio de Ciencia, Innovación y Universidades of Spain (grant No.: RYC-2014-15357). The authors thank the National Research Foundation of the Ministry of Education, Republic of Korea (Basic Science Research Program grant No.: 2018R1A2B5A02023190) and Ministry of Education, Science and Technological Development of Serbia (Contract No. 451-03-68/2020-14/200135) for financial support