Hybrid Metal-Semiconductor Meta-Surface Based Photo-Electronic Perfect Absorber

Abstract

Metal films and semiconductor materials have been utilized for numerous optoelectronic devices due to the impressive electrical features. Nevertheless, the feasible way for achieving light anti-reflection or perfect absorption from opaque metal films and high-index semiconductors has not been established yet. In this work, we numerically propose and demonstrate a new functional metal–semiconductor slab, which can produce perfect light absorption in the optical range. High-index semiconductor resonators have been used to provide strong optical field coupling with the incident light. For the Ag–Si resonant slab consisting of a silicon rings array in the Ag slab, dual-band light absorption with the absorption efficiency above 99% is achieved due to the hybridized coupling of photonic and plasmonic modes for the Si and Ag resonators. Additionally, tri-band light absorption can be obtained when a paired silicon rings array is used. Moreover, these absorption properties can be spectrally manipulated via tuning the structural parameters. Furthermore, the absorber scheme is observed to be realizable by other metals and semiconductors. These optical and structural features can not only provide alternative ways for multi-band light absorption but also suggest new insight on the functional optoelectronics such as the infrared photo-detectors, hot-electron excitation, and nonlinear optics.