Open AccessGold-black phosphorus nanostructured absorbers for efficient light trapping in the mid-infrared
Author(s) -
Romil Audhkhasi,
Michelle L. Povinelli
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.398641
Subject(s) - materials science , optoelectronics , absorption (acoustics) , photodetector , black phosphorus , dielectric , optics , wavelength , thin film , layer (electronics) , infrared , nanotechnology , physics , composite material
We propose a gold nanostructured design for absorption enhancement in thin black phosphorus films in the 3-5 µm wavelength range. By suitably tuning the design parameters of a metal-insulator-metal (MIM) structure, lateral resonance modes can be excited in the black phosphorus layer. We compare the absorption enhancement due to the resonant light trapping effect to the conventional 4n2 limit. For a layer thickness of 5 nm, we achieve an enhancement factor of 561 at a wavelength of 4 µm. This is significantly greater than the conventional limit of 34. The ability to achieve strong absorption enhancement in ultrathin dielectric layers, coupled with the unique optoelectronic properties of black phosphorus, makes our absorber design a promising candidate for mid-IR photodetector applications.