Enhancement of UV Photodetector properties of ZnO nanorods/PEDOT: PSS Schottky junction by NGQD Sensitization along with Conductivity improvement of PEDOT:PSS by DMSO additive

Schottky junction ultraviolet (UV) photodetector was fabricated by spin coating a hole conducting polymer, poly 3,4-ethylenedioxythiophene: polystyrene sulfonate (PEDOT:PSS) on hydrothermally grown zinc oxide (ZnO) nanorod arrays. The UV detector performance was significantly improved two step process. Firstly, ZnO nanorods were modified by sensitizing N doped grapheme quantum dots (NGQDs) for better photoresponce behavior. Afterwards, the junction properties as well as photoresponse was enhanced by modifying electrical conductivity of PEDOT: PSS layer with organic solvent (DMSO). Our NGQD decorated ZnO NRs/DMSO-PEDOT: PSS Schottky junction device demonstrated superior external quantum efficiency (EQE similar to 90063 % ) and responsivity (R-lambda similar to 247 A/W) at 340 nm wavelength and -1V external bias. The response and recovery times of the final photodetector device was very fast compared to GQD as well as NGQD modified and pristine ZnO nanorod based detectors.