Pd/ZnO Schottky Ultraviolet Photodiode Fabricated on ITO Using rGO Seed Layer

This letter reports the high-performance ultraviolet (UV) Pd/ZnO Schottky photodiodes fabricated on indium tin oxide (ITO) using reduced graphene oxide (rGO) as seed layer. Electrophoretic deposition method has been used for the deposition of rGO layer on ITO substrate. A comparative study of Pd/ZnO devices with and without the rGO seed layer is carried out. The current-voltage (I-V) measurements of asfabricated Schottky photodiodes having rGO as seed layer have shown responsivity ~1.32 A/W; which is around 26 times compared with responsivity ~0.05 A/W of a Pd/ZnO/ITO photodiode without rGO seed layer both measured at -2 V reverse bias voltage. Good contrast ratio (~74.91) and detectivity (~2.49 × 10
¹¹
mHz
^1/2
W
^-1
) are observed for rGO seed layerbased devices when the device is illuminated by an UV source of ~650 μW output power at ~365 nm. Hence, this letter reports about utilizing rGO as seed layer for improving the performance of Pd/ZnO-based Schottky UV photodiodes.