  A simple perfect absorption structure is proposed to achieve the high
efficiency light absorption of monolayer molybdenum disulfide (MoS 2 ) 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 2 . 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 2 . The novel idea of using critical coupling to
enhance the light-MoS 2 interaction can be also adopted in other atomically
thin materials. And the meaningful improvement and tunability of the absorption
in monolayer MoS 2 provide a good prospect for the realization of
high-performance MoS 2 -based optoelectronic applications, such as
photodetection and photoluminescence.
