High‐Performance UV Photodetectors Based on ZnO Hierarchical Nanostructures Grown on Aerosol‐Printed 3D Ag Mesh

The development of energy‐efficient and highly sensitive ultraviolet (UV) photodetectors (PDs) is vital for applications in environmental monitoring, biomedical diagnostics, and optical communication. While conventional thin‐film devices are limited by low surface area and restricted light absorption, three‐dimensional (3D) nanostructures offer a promising alternative by enhancing light‐matter interaction and carrier collection. This study introduces a 3D UV photodetector architecture composed of aerosol‐printed silver (Ag) mesh combined with seedless hydrothermally grown zinc oxide (ZnO) nanorods (NRs). The aerosol printing process is optimized to form high‐aspect‐ratio Ag mesh structures on glass substrates, which serve simultaneously as conductive scaffolds and nucleation sites, enabling the direct growth of vertically aligned ZnO NRs. The resulting 3D Ag/ZnO structure forms Schottky junctions that facilitate efficient charge separation and internal gain, thereby enhancing the PDs' performance. Under a low operating bias of 0.1 V and weak UV illumination (1 μW cm −2 ), the device exhibits outstanding performance, including a responsivity of 1.2 × 10 3 A W −1 , detectivity of 8.52 × 10 12 Jones, and an external quantum efficiency (EQE) of 4.08 × 10 5 %. Additionally, the PDs are tested over a range of temperatures, showing excellent thermal stability. These developments provide a versatile platform to design hierarchical nanoarchitectures for next‐generation optoelectronic systems.