Interfacial self-assembly of ultrathin polydiacetylene/graphene oxide nanocomposites: A new method for synergetic enhancement of surface charge transfer without doping

A new method for interfacial self-assembly of graphene oxide (GO) and 10,12-pentacosadiynoic acid into nanometer-thick light-absorbing films exhibiting synergetic enhancement of conductive properties is developed. The blue form of polydiacetylene (PDA) nanopatches with a thickness of 5–10 nm is stabilized through the interactions between GO and PDA. The hole-transferring polymer decreases contact resistance in the GO sublayer through “healing” the gaps between the GO nanosheets. The separation of electron-hole pairs at the PDA/GO interface under applied electric field leads to a doping-free enhancement of the in-plane surface conductivity by 6 orders of magnitude up to 46.4 S·cm⁻¹ with respect to those of individual components. These PDA/GO nanocomposites were applied as ultrathin diodes/photodiodes in a solar cell by creating a PDA/C₆₀ heterojunction and a light-induced cross-layer charge transfer. The method can be adapted to a variety of polymerizable light-absorbing surfactants for fabricating GO-based nanohybrids for photoelectronics.