A photodiode with high rectification ratio based on well-aligned ZnO nanowire arrays and regioregular poly(3-hexylthiophene-2,5-diyl) hybrid heterojunction

A photodiode was fabricated based on well-aligned ZnO nanowire arrays (ZNAs) and regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) hybrid heterojunction. The current-voltage (I-V) characteristics of ITO/ZNAs/P3HT/Ag device in the dark and under illumination with a solar simulator were investigated in detail. The results demonstrated that the device showed good diode characteristics in the dark and under illumination. The device exhibited a high rectification ratio (RR) of 3211 at 2 V and a low turn-on voltage of 0.5 V in the dark. Also, the RR of the device as a function of illumination intensity was observed, and the transportation process of charge carriers in the diode under illumination was illuminated in terms of energy band diagram.