Bio-inspired hierarchical plasmonic meta-architectures for silicon-based near-infrared sensing

Abstract

Hierarchical photonic architectures in nature, exemplified by peacock feathers, encode rich optical functionalities through nested structures spanning multiple length scales. By contrast, metasurfaces are typically built on single-level, planar designs, where one-scale optimization constrains three-dimensional control of light concentration and near-field localization. Here, we report a bio-inspired hierarchical plasmonic hot-carrier infrared detector in which microscale resonant motifs are integrated with embedded subwavelength features to realize multiscale field shaping at the device level. By co-designing the hierarchical metastructure directly with a TiN/Si Schottky junction, the metasurface functions as an in-device light-harvesting and field-engineering element, avoiding reliance on external optical add-ons and offering a practical route toward more compact architectures. The hierarchical geometry delivers a pronounced performance gain and serves as a multiscale tuning knob that programmably reshapes the near-field landscape and modulates device response by design. As a result, the device exhibits enhanced infrared absorption and improved hot-carrier collection, achieving a responsivity of 56 mA/W and a detectivity of 3.42×1010 Jones at 1200 nm under room-temperature, zero-bias operation. Our results establish hierarchical plasmonic meta-architectures as a structure-driven strategy for high-performance hot-carrier infrared (IR) detection and underscore their potential for metasurface-detector co-design toward wafer-scale metasurface-detector co-integration for next-generation, full-field infrared detection.