Flexible and passive photo sensor based on perylene/graphene composite

Graphene-based composites represent a new class of materials with potential for many electronic applications. Especially, any polymer's property can be tuned by attaching it to graphene. In this paper, we propose a passive photo sensor based on a single layer of perylene/graphene composite, which is deposited in comb type silver electrodes separated as 50 μm spacing. The electrical conductivity of perylene is increased by blending with graphene. Photo sensing layer (120 nm thick) and Silver electrodes (50 μm width and 350 nm thick) are deposited on poly(ethylene terephthalate) (PET) substrate through electro-hydrodynamic (EHD) system, which is cost effective, environmentally friendly, and non-vacuum e-printing technology. The proposed photo sensor detects a terminal resistance inversely varied by an incident light in the range between 78 GΩ in dark and 25 GΩ at light intensity of 400 lux. The device response is maximum on wavelength range 465-535 nm at blue light. The device exhibited bendability up to 4 mm diameter for 1000 endurance cycles. The surface morphology analysis is carried out with FE-SEM and microscope.