Preparation of PEDOT:PSS thin films doped with graphene and graphene quantum dots

• Stable colloid of graphene and graphene quantum dots was prepared.
• Thin films of PEDOT:PSS are doped with functionalized graphene.
• PEDOT:PSS chains wrap around graphene and graphene quantum dots.
• Doped PEDOT:PSS films have lower sheet resistance and high transparency.

Enhanced conductivity, transparency and stability are the most important factors to consider in order to prepare electrodes for optoelectronic devices. In this paper, we investigated the properties of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films doped with graphene and graphene quantum dots. Samples were deposited by spin-coating onto glass substrates. Thin films were characterized by UV–vis and Raman spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM) and four-point probe measurements. It was found that both graphene and graphene quantum dots improve the conductivity of PEDOT:PSS films with only small decrease in transparency. AFM and SEM analysis showed homogenous distribution of spherical nanoparticles of graphene quantum dots and irregular shaped nanoparticles of graphene in PEDOT:PSS.