Polystyrene nanoparticles enhance photo responsivity of graphene photodetector

Graphene has attracted much attention as a candidate for plane material in optoelectronics and optoelectronic devices for its exceptional physical properties. However, its low photo responsivity has limited its development and applications in photodetectors. In this paper, we propose a new method to enhance the photo responsivity of a graphene photodetector by integrating Polystyrene Nanoparticles (PSNs) into the graphene photodetector, dropping them onto the graphene surface using a glass micropipette. The results show that the photocurrent of the graphene photodetector is linearly enhanced with increasing PSNs concentration, and achieves a maximum enhancement by up to 71% with 500 nm PSNs under the incident light of 470 nm. The enhancement of the photo responsivity varies as the light wavelength changes with PSNs of the same diameter and it is demonstrated by simulation that the photo responsivity is maximally enhanced when the wavelength of the incident light is equal to the diameter of the PSNs. Our approach not only promotes the development of graphene in optoelectronics, but also has the potential for multicolor photodetection.