Broadband absorption enhancement with ultrathin MoS2 film in the visible regime* *Project supported by the National Natural Science Foundation of China (Grant No. 61405217), the Zhejiang Provincial Natural Science Foundation, China (Grant No. LY20F050001), the Anhui Polytechnic University Research Startup Foundation, China (Grant No. 2020YQQ042), and the Pre-research Project of Natural Science Foundation of Anhui Polytechnic University, China (Grant No.

Abstract

The broadband absorption enhancement effect in ultrathin molybdenum disulfide (MoS2) films is investigated. It is achieved by inserting the MoS2 film between a dielectric film and a one-dimensional silver grating backed with a silver mirror. The broadband absorption enhancement in the visible region is achieved, which exhibits large integrated absorption and short-circuit current density for solar energy under normal incidence. The optical properties of the proposed absorber are found to be superior to those of a reference planar structure, which makes the proposed structure advantageous for practical photovoltaic application. Moreover, the integrated absorption and short-circuit current density can be maintained high for a wide range of incident angles. A qualitative understanding of such broadband absorption enhancement effect is examined by illustrating the electromagnetic field distribution at some selected wavelengths. The results pave the way for developing high-performance optoelectronic devices, such as solar cells, photodetectors, and modulators.