Investigation on the suitability of water/polyethylene glycol solutions for GO layer deposition in GO/Ag/GO films for transparent conducting electrode

A hybrid trilayered transparent conducting electrode (TCE) based on graphene oxide (GO) in the form of GO/Ag/GO multilayer synthesized using GO suspension in water and polyethylene glycol (PEG) is investigated for their suitability as TCE. The GO layers prepared from modified Hummer’s method were suspended in water and EG solution separately and spin coated on a glass substrate. Ag film (~ 8 nm) was DC sputtered coated on these films before a second spin coat of GO layer to prepare two variants of trilayered structure (GO/Ag/GO). AFM/SEM images verified the smooth surface topology. Structural analysis by Raman spectroscopy showed shifting and broadening of GO peak, which represents defects/disorder with obtained ID/IG ratio as 0.70 and 0.98 for EG and DI water-based trilayered structure, respectively. Hall measurements concluded superior electrical and optical properties; with an average transmittance of ~ 75% in visible region, sheet resistance Rs = 24.43 Ω/sq, and high charge carrier concentration (n = 2.11 × 1022 cm−3) in films prepared with GO suspension in EG. The other combination prepared with DI water showed transmittance of ~ 73% and sheet resistance of 34.73 Ω/sq. X-ray photoelectron spectroscopy technique was further used to determine quantitative and chemical state information of elements by depth profile measurement of the trilayer electrode.