MoS2-based broadband and highly efficient solar absorbers.

Abstract

In order to obtain broadband, highly efficient, wide-angle, and polarization-insensitive solar absorbers, we propose a universal configuration consisting of monolayer molybdenum disulfide (MoS2) and the metal-insulator-metal structure, which gives rise to significant absorption enhancement of the MoS2 layer. Light trapping structures with silver square-, circle-, and crossed-shaped resonators are investigated. The localized surface plasmon resonances among the silver resonators induce prominent interaction between the incident photon and MoS2 layer, contributing to efficient absorption of light energy. Simulation results show that the absorber made of square patches enables the best performance and realizes absorptance higher than 90% from 400 to 666 nm and an average absorptance greater than 91% in the range of 400-700 nm. The average light absorption within the MoS2 layer reaches 74% in the visible spectrum, which is one of the highest levels for the existing MoS2-based absorbers. Meanwhile, the polarization-independent designs exhibit good angle tolerance within 50° incidences. Such a universal structure can also obtain broadband and highly efficient absorption by using other transition metal dichalcogenides such as MoSe2, WS2, and WSe2, which indicates that the configuration has great applicability in solar energy absorption of 2D materials. The proposed solar absorbers with simple configuration and broadband absorption in wide incident angles have potential in applications such as solar cells, photovoltaic devices, and blackbody materials.