Tailoring UV Responsivity and Quantum Efficiency of ZnO Nanorod‐Polymer‐Dispersed Cholesteric Liquid Crystal Heterostructure‐Based Photodetector Device

Abstract The development of an advanced ultraviolet (UV) photodetector that integrates a polymer‐dispersed cholesteric liquid crystal (PDCLC) with a ZnO nanorods (ZNRs) heterostructure is reported. The ZNRs are synthesized via a hydrothermal method and then spin‐coated with PDCLC, resulting in a photodetector with notably enhanced electrical and optical performance. Under 365 nm UV illumination at 5 mW cm⁻² and 10 V, the PDCLC‐coated ZNRs array achieved a high photocurrent density of 171 µA cm⁻², showcasing significant gains over devices without PDCLC. The novel ZNRs‐PDCLC heterostructure demonstrated a remarkable responsivity of 172.21 mA W⁻¹ and an external quantum efficiency (EQE) of 58.44%, a substantial improvement compared to ZNRs‐only (72.27 mA W⁻¹, 23.39% EQE) and ZnO seed layer‐based devices (14.48 mA W⁻¹, 4.8% EQE). This enhancement stems from the PDCLC effective sensitization, which promotes charge carrier activation and energy band alignment in ZnO, resulting in a dynamic, time‐responsive photodetection. These findings underscore the potential of ZNRs‐PDCLC heterostructures to drive advances in high‐performance UV photodetectors.