Development of New Sustainable Near-UV Photodetector Devices Based on Polymer/ZnO NR Heterojunctions With Improved Responsivity

This article presents a convenient method for fabricating hybrid heterojunctions using poly (N-vinylcarbazole) (PVK) and a 1-D zinc oxide nanorod (ZnO NR) array for photodetector (PD) development. In this context, PVK and ZnO NRs were employed as electron donor and acceptor, respectively. First, ZnO NRs were hydrothermally synthesized through a two-step procedure at low temperatures on an n-type silicon substrate. Ohmic contacts were integrated by incorporating graphite and eutectic In-Ga (eGaIn) in to the PVK film and Si substrate, respectively. The eGaIn/Si/ZnO NRs/PVK/graphite PD structures’ fundamental electrical parameters were extracted from theI–Vresponse in dark and under illumination conditions. It was found that the device displayed remarkable sensitivity to ultraviolet (UV) light exposure, owing to a responsivity of 35 mA·W⁻¹, with notable reproducibility. What is more, the structure demonstrates an open-circuit voltage, short-circuit current density, and ideality factor of 0.28 V, 237.2μA·cm⁻², and 2.3, respectively. The origin of the ZnO/PVK photoconductive properties is explained using the carrier transport mechanism at the interfaces. Moreover, the photoelectrical parameters of the PVK/ZnO NR structure were precisely evaluated through a combined physical–mathematical–numerical approach to unravel the physical mechanisms governing the operation of such PDs. The results of this research reveal promising avenues for flexible and highly sensitive PDs, opening wide potential applications in advanced communication systems, and/or environmental monitoring.