Facile Fabrication of Ultrasensitive Honeycomb Nano-Mesh Ultraviolet Photodetectors Based on Self-Assembled Plasmonic Architectures.

The dilemma of harvesting fugacious photons by photoactive nanomaterials of limited absorption volume fundamentally hinders the photodetection at relatively lower light intensities. To address the insufficient light utilization efficiency, spatial light confinement becomes an effective and promising approach. High-performance ultraviolet (UV) photodetectors based on the self-assembled Au nanoparticle/ZnO honeycomb nano-mesh (Au NP/ZnO HN) are demonstrated through a facile solution-processed method on anodized aluminum oxide (AAO) membranes. The congregated geometry of the self-assembled ZnO HNs is well-defined by the AAO matrixes, which also effectively collects the transmitted light beams back to the photoactive layers. Benefiting from surface plasmon resonance, the enhanced absorption of the ZnO HNs is eventually obtained via the recursive light utilization between Au NPs and AAO matrixes as a function of AAO pore diameters (DAAO). With a systematic control of the photodetector configurations, an optimal performance is obtained with growth duration of the ZnO HNs for 40 min on the AAO substrates (DAAO = 100 nm), and an excellent responsivity of 23.4 A/W is witnessed even under a relatively low light intensity of 0.4 mW/cm2, providing a novel route to realize high-performance UV photodetection under low-power illumination.