Capacitance–Voltage Investigation of Encapsulated Graphene/Silicon Solar Cells

In this article, the effect of graphene/silicon Schottky junction solar cells (G/Si SJSCs) encapsulation is investigated in terms of capacitance–voltage (
${C}$
–
${V}$
) curves in the forward bias region. Capacitance behavior can give accurate information on interface properties, especially when it is considered at positive voltage. The detection of a double peak on such curve is related to nonuniform interface properties at the graphene/silicon interface. To passivate the interface, G/Si SJSCs have been exposed to HNO
₃
vapors and the effectiveness of HNO
₃
doping has been exploited as well as its volatility, assessing the need for encapsulation.
${C}$
–
${V}$
curves collected over time from doped unencapsulated G/Si SJSCs clearly exhibited a modification of capacitance behavior, revealing a fading of doping beneficial effects over a week. On the contrary,
${C}$
–
${V}$
curves acquired from encapsulated samples evidence that capacitance behavior did not modify over time.