Photovoltaic and phototransient interface states properties of nanocomposite Fe3O4–graphene/n-Si/Al photodiode

• A photodiode based on Fe3O4–graphene/n-Si/Al diode was fabricated.
• Ag/Fe3O4–graphene/n-Si device a gives a Isc of 0.111 mA and Voc of 375 mV under 1.5 A.M.
• Ag/Fe3O4–graphene/n-Si device exhibited a photocapacitance behavior.

A photodiode based on Fe3O4–graphene/n-Si/Al diode was fabricated. The electrical and capacitance properties of the diode were investigated by transient current and capacitance measurements. Ag/Fe3O4–graphene/n-Si photovoltaic device gives Isc of 0.111 mA and Voc of 375 mV under 1.5 A.M. The maximum electrical power Pmax value of the device was found to be 7.567 μV. This suggests that the studied photovoltaic device can be used as a microvoltage generator. The capacitance of the device increases with illumination. This indicates that the device exhibits a photocapacitance behavior. This behavior was analyzed by transient photocapacitance measurements. The transient interface states density plots of the diode were obtained. The photocapacitance mechanism was explained with the change in the interface states.