ZnO/PPy Hybrid Heterojunction as an Ultraviolet Photosensor

The electrodeposition method was used to deposit a zinc oxide (ZnO) layer on an indium tin oxide substrate. Polypyrrole (PPy) was deposited also by the electrodeposition method on the same ZnO layer to form a ZnO/PPy interface. Scanning electron microscopy was performed to investigate the morphology of the organic-inorganic interface. The p-n junction so formed was subjected to electrical studies. The junction was found to be sensitive to exposure to ultraviolet light, which increased the junction's current density. The diode was found to have an open-circuit voltage (V (oc)) of 0.518 V and a short-circuit current density (J (sc)) of 9.86 x 10(-7) A/cm(2). The fill factor was estimated to be 0.37 with a rectification ratio of 93. Photoluminescence studies revealed quenching of the excitonic emission at the ZnO/PPy interface. The interface is thus found to be responsible for the effective separation of charge carriers.