Graphene-based Schottky junction solar cell

Graphene’s novel properties have been of great interest for purposes of energy harvesting. In this study, we exploit graphene’s photovoltaic properties to this end. We built graphene energy harvesting (GEH) devices consisting of wells etched into SiO₂ with a gold tip at the bottom. Graphene was positioned over the devices so the area of the sheet above the well is freestanding, and the area on the outside lays flat on the SiO₂. The positive terminal of an adjustable power supply is attached to the tip. The graphene is attached to two parallel branches that each contain a diode-connected BJT transistor and an ammeter. The transistors on the two branches are oriented in opposite directions for the purpose of current rectification. The other side of these two branches and the low end of the power supply are wired to ground. An LED is positioned above the graphene and alternates between on and off states. On states coincide with a higher current. Photocurrent data under various biasing conditions will be presented.