Mechanism of enhanced photocurrent of graphene by polymer and metal nanoparticles

We present a novel method for controlling the electronic band structure and photocurrent for graphene by introducing polymer interlayer and metal nanoparticles. Specifically, polystyrene spincoated onto the graphene led to a slight change in the electric (p-doping) and optoelectronic properties (photocurrent) of the graphene as revealed by electrical characterizations and photocurrent mapping analyses, respectively. When polystyrene was combined with gold nanoparticles, the plasmonic-enhanced photocurrent was consistent across the graphene surface. Furthermore, the p-doping effect by polystyrene and gold nanoparticles was evaluated by Raman spectrum and 2D/G Raman mapping analyses.