Broadband photosensing using p-type cupric oxide nanorods/conducting polymer Schottky junction

Abstract

Broadband photosensing properties has been demonstrated using p-type CuO nanorods/conducting polymer poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) Schottky junction. CuO nanorods have been grown on FTO coated glass substrate by low cost hydrothermal technique. Schottky junction device was fabricated by spin coating the polymer layer on top of the nanorods. The rectifying property and diode parameters of the device have been investigated using current-voltage measurements. The build in potential at the nanorods/polymer junction was studied using Kelvin Probe Force Microscopy (KPFM). The photodetector parameters such as transient decay time (τ), rise and fall time, external quantum efficiency (EQE), responsivity and detectivity have been studied in details. Such metal oxide semiconductor/polymer heterojunction device demonstrated broadband photoresponse (300–700 nm) with highest EQE ~67.5% and responsivity ~0.3A/W at 560 nm under 0.5 V reverse bias.