Controllable 3D Plasmonic Nanostructures for High Quantum Efficiency UV Photodetectors Based on 2D and 0D Materials
Confinement of the incident light waves is often challenging for enhanced light-matter interaction and hence the development of high performance photodetectors with a wide range of semiconductors in nano-scaled size, especially for the 2D materials with axially limited volume. An approach has been proposed to spatially extend light confinement from 2D to 3D with a 3D plasmonic structures, i.e. an Anodic Aluminum Oxide (AAO) matrix decorated with Au nanostructures. The incident light beams are initially concentrated by the Au nanostructures, and the strong plasmon optical interference within AAO matrixes subsequently offers an effective way to trap the transmitted lights from the Au NSs layers, which are recursively collected by the Au nanostructues. The optical properties of the 3D plasmonic nanostructures exhibit strong morphological dependence, which can be evidenced by tunable Raman scattering enhancement. The enhancement factor of the surface-enhanced Raman scattering of R6G molecules can be as high as 1 × 108. More importantly, the 3D plasmonic nanostructures are successfully applied in different low dimensional materials. Such 3D plasmonic nanostructures overcomes the limited light absorption of the ultra-thin 2D p-MSB nanoribbons, resulting in a high quantum efficiency up to 1068% under 0.5 mW/cm2 UV light illumination.