Polarization-insensitive broadband absorption enhancement with few-layer MoS2 film

Abstract

A polarization-insensitive broadband absorber with few-layer molybdenum disulfide (MoS2) films is designed. The proposed absorber is composed of a dielectric antireflective coating and an ultrathin MoS2 film deposited on a metal square resonator array backed with a metallic mirror. It is shown that the polarization-insensitive absorption enhancement in the ultrathin MoS2 film is realized in the visible region for normally incident light. The distributions of electric field intensity at several resonant wavelengths are investigated to intuitively disclose the physical origin of such phenomenon. Moreover, the optical performances, i.e. the absorption spectra versus the change of incident angle for both polarizations, the angular sensitivity of the integrated absorption and the short-circuit current density, are simulated and examined, all of which outperforms the referenced planar structure. It is believed that the conclusions provide a promising way to design and fabricate ultrathin MoS2 solar cells and other novel optoelectronic devices.