Photodetector based on silicon-graphene heterojunction fabricated through rubbing-in technology

Abstract This article provides an insight into the fundamental physics of a rubbed-in graphene over silicon (Si) Schottky photodiode for its affordable applications in visible light and infrared (IR) irradiation. The graphene powder was deposited over the surface of boron-doped Si (p-Si) through rubbing-in (rolling-pressing) technology. The maximum reversed biased current observed was -75 microampere at -5V and the rectifying ratio of 240 was obtained experimentally at 1 V. The current density-voltage characteristics of the p-Si-graphene junction were investigated, then samples were measured for its rectifying ratio and results showed the tendency of a photodiode detector to operate under IR and visible light regions. The device was saturated at the open-circuit voltage values of 15 mV for infrared and 1.8 mV for visible light, respectively. The surface morphology of the device was performed through scanning electron and atomic force microscopy. The reason behind the device performance has been studied considering its junction quality, low shunt resistance, bulk, and surface recombination mechanism which drastically may affect device performance. Hence, further layers and device optimization techniques were proposed to enhance photodiode performance. The study allows us to follow footsteps toward the fabrication of fast responsive, large-scale, and budget-friendly photodiode by using transfer-less and budget-free fabrication technology for proposing efficient photo-detectors on large scale as well as for educational purposes.