Electrical and optical properties of poly(3,4-ethylenedioxythiophene) oxidized with poly(4-styrenesulfonate) and AuCl₃-doped reduced graphene oxide/single-walled carbon nanotube films for ultraviolet light-emitting diodes

We report the effects of poly(3,4-ethylenedioxythiophene) oxidized with poly(4-styrenesulfonate) (PEDOT:PSS) and gold chloride (AuCl₃) co-doping on the electrical and optical properties of reduced graphene oxide (RGO)/single-walled carbon nanotube (SWNT) films fabricated by dip-coating methods. The RGO/SWNT films were doped with both AuCl₃ dissolved in nitromethane and PEDOT:PSS hole injection layers by spin coating to improve their electrical properties by increasing the work function of the RGO/SWNT films, thereby reducing the Schottky barrier height between the RGO/SWNT and p-GaN films. As a result, we obtained a reduced sheet resistance of 851.9 Ω/Ω and a contact resistance of 1.97 × 10^-1 Ω·cm², together with a high transmittance of 84.1% at 380 nm. The contact resistance of these films should be further reduced to fully utilize the feature of the electrode scheme proposed in this work, but the current result suggests its potential use as a transparent conductive electrode for ultraviolet light-emitting diodes.