Approaching perfect absorption of monolayer molybdenum disulfide at visible wavelengths using critical coupling

Abstract

A simple perfect absorption structure is proposed to achieve the high efficiency light absorption of monolayer molybdenum disulfide (MoS) by the critical coupling mechanism of guided resonances. The results of numerical simulation and theoretical analysis show that the light absorption in this atomically thin layer can be as high as 98.3% at the visible wavelengths, which is over 12 times more than that of a bare monolayer MoS. In addition, the operating wavelength can be tuned flexibly by adjusting the radius of the air hole and the thickness of the dielectric layers, which is of great practical significance to improve the efficiency and selectivity of the absorption in monolayer MoS. The novel idea of using critical coupling to enhance the light-MoS interaction can be also adopted in other atomically thin materials. The meaningful improvement and tunability of the absorption in monolayer MoS provides a good prospect for the realization of high-performance MoS-based optoelectronic applications, such as photodetection and photoluminescence.

High Quality Factor, High Sensitivity Metamaterial Graphene—Perfect Absorber Based on Critical Coupling Theory and Impedance Matching

“…The rationale is that minimizing the reflectivity by adjusting the degree of matching between free room and impedance (Z = 1), and for the purpose of removing the transmittance of light by using a metal mirror which has a definite thickness. Figure 2c,d show the functional relationship between the permittivity of real and imaginary parts of monolayer graphene with chemical potential (µ c ) [46]. the absorption of TM polarization at a wavelength of 1158 nm reaches about 100%, while the TE polarization has the same geometrical size of the structure, the absorption peak wavelength shifts to the left, and the absorption peak wavelength is 1152 nm.…”

“…The rationale is that minimizing the reflectivity by adjusting the degree of matching between free room and impedance (Z = 1), and for the purpose of removing the transmittance of light by using a metal mirror which has a definite thickness. Figure 2c,d show the functional relationship between the permittivity of real and imaginary parts of monolayer graphene with chemical potential (μc) [46]. Figure 3a-c.…”

Tunable Broadband Solar Energy Absorber Based on Monolayer Transition Metal Dichalcogenides Materials Using Au Nanocubes

“…The light absorption rate for our proposed nanostructure of monolayer WS2, MoSe2 and WSe2 are shown in Figure 9a-c. The data for WS2, MoSe2 and WSe2 is obtained from Jiang et al [37]. The selected geometric parameters are exactly the same as the proposed MoS2-based Figure 9a-c.…”

“…This process only needs the participation of photons and does not require additional phonons, which makes it much easier to generate and has a higher quantum efficiency. Compared with pure graphene, TMDCs have been considered as more preferable materials for applications, because pure graphene's band-gap is zero [37] and its electrical conduction is only stimulated by electronic heat, which greatly limits its application in many fields. TMDCs have a tunable bandgap ranging from 1 to 2 eV [38], which provide opportunities for manufacturing photoelectron devices.…”

“…In the last decade, an increasing number of strategies have been proposed for light absorption enhancement of monolayer MoS 2 . Based on the critical coupling mechanism, Xiao et al [37] added an air chamber into a polymethyl methacrylate (PMMA)-SiO 2 -Ag three-dimensional structure, which greatly enhanced the absorption of monolayer MoS 2 . Hua et al [42] enhanced Tamm Plasmon (TP) modes by inserting monolayer MoS 2 into a grid composed of titanium dioxide and silicon dioxide, and then enhanced its absorption to 96%.…”