Abstract
In this study, we investigate a physical mechanism to improve the light absorption efficiency of graphene monolayer from the universal value of 2.3% to about 30% in the visible and near-infrared wavelength range. The physical mechanism is based on the diffraction coupling of surface plasmon polariton resonances in the periodic array of metal nanoparticles. Through the physical mechanism, the electric fields on the surface of graphene monolayer are considerably enhanced. Therefore, the light absorption efficiency of graphene monolayer is greatly improved. To further confirm the physical mechanism, we use an interaction model of double oscillators to explain the positions of the absorption peaks for different array periods. Furthermore, we discuss in detail the emerging conditions of the diffraction coupling of surface plasmon polariton resonances. The results will be beneficial for the design of graphene-based photoelectric devices.
Highlights
Accepted: 4 January 2022When the visible and near-infrared electromagnetic waves are normally incident on the surface of an undoped graphene monolayer suspended in the air, only several percentage points of electromagnetic waves are absorbed by the graphene monolayer
We study how to use plasmonic surface lattice resonances to improve the light absorption efficiency of graphene monolayer in the visible and near-infrared wavelength range
The Au nanospheres on the surface of the graphene monolayer are arranged into periodic arrays, which are covered by the layer of SiO2
Summary
When the visible and near-infrared electromagnetic waves are normally incident on the surface of an undoped graphene monolayer suspended in the air, only several percentage points of electromagnetic waves are absorbed by the graphene monolayer. The absorption efficiency (A) of graphene monolayer can be estimated by its fine structure constant (α), which is, A = πα = πe2 /hc ≈ 2.3%. The absorption efficiency of 2.3% is a universal value, which does not depend on the wavelength of electromagnetic waves in near-infrared, visible, and even violet regions [1,2]. Due to the considerably good optical and electrical properties, graphene is known to hold a great promising potential in photoelectric devices, such as photodetectors, modulators, perfect absorbers, photovoltaics, photocatalysts, etc. The absorption efficiency of 2.3% is too low for the efficient operation of graphene-based photoelectric devices. To overcome the difficulty, a number of different solutions have been proposed [19,20], which mainly include surface plasmon polariton resonances [21,22], magnetic resonances [23,24], guided mode resonances [25,26], total internal reflections [27,28], Fabry-Perot resonances [29,30], surface bound states of photonic crystals [31,32], waveguide modes [33], coherent optical
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
