ZnO nanowire based visible-transparent ultraviolet detectors on polymer substrates

The fabrication and characterization of fully visible-transparent and flexible ultraviolet (UV) detectors, on polyethylene 2,6-naphthalate (PEN) with active channels of zinc oxide nanowires and ohmic indium tin oxide contacts, are reported and discussed. The fabricated detector has an average transmittance of 80 in the visible spectral range and is most responsive at or below 370 nm, the onset of UV light, with a UVvis rejection ratio of 1.42 × 10 ³. A five orders of magnitude difference in the photocurrent, between UV illumination and dark conditions, are also observed. The single-sided UV response further shows that the PEN substrate performs well as a UV reflector. The noise analysis on the nanowire UV detector indicates a noise equivalent power and detectivity (D*) of 5.88 × 10 ^-13 WHz ^-0.5 and 2.13 × 10 ⁹ cm Hz ^0.5 W ^-1, respectively.