Photocurrent and Photocapacitance Properties of an Al/Coumarin/p-Si/Al Photodiode

A photodiode was prepared using a coumarin organic semiconductor and a p-type silicon wafer. The photocurrent-voltage characteristics of the Al/coumarin/p-Si/Al diode were investigated under solar light illumination. It is seen that the current of the diode increased suddenly with solar light illumination. The photoresponse value of the diode was found to be 678 under 1000 W/m2. The capacitance-voltage (C-V) characteristics of the diode were analyzed from low frequency to high frequency. The capacitance and conductance of the junction interface was corrected by series resistance. The diode exhibits a dispersive capacitance behavior and the interface density of the diode was analyzed by the corrected capacitance and conductance. It is found that the Al/coumarin/p-Si/Al diode is a photodiode with the obtained photoconductive parameters and can be used as a photodiode in optic communications.