Phenomenal improvement of external quantum efficiency, detectivity and responsivity of nitrogen doped graphene quantum dot decorated zinc oxide nanorod/polymer schottky junction UV detector

Photodetector properties of nitrogen doped graphene quantum dot (NGQD) sensitized ZnO nanorods/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) Schottky junction has been investigated. The photodetector demonstrated superior external quantum efficiency (EQE) (∼57681% at −1 V bias) at wavelength ∼340 nm, which is 4 times higher than graphene quantum dot (GQD) modified ZnO NRs based detector and 35 times higher than pristine ZnO NRs detector. NGQD modified detectors also showed higher responsivity (∼158 A/W), detectivity (8.7 × 10 12 Hz 1/2 /W) at 340 nm wavelength. The response and recovery times of the detector is very fast compared to GQD modified and pristine ZnO nanorod based detectors. Our UV detector also demonstrated higher photocurrent even at lower intensity range of incident light.