Broadband Light Harvesting Enhancement of MoS2/Graphene Bilayer Solar Cell via Metal Nanosquare Arrays-Dielectric-Metal Structure

Abstract

Low absorptance of transition metal dechalcongenides has limited their potential applications in photon detection and light harvesting, which motivates the quest for new approaches to improve the absorption in these systems. Here, we demonstrate a broadband and polarization-independent metal nanosquare arrays-dielectric-metal stucture to improve the light absorption in the solar cells based on bilayer of MoS2/graphene. By performing three-dimensional electromagnetic simulations, it is revealed that the optical absorption in the monolayer MoS2 can be significantly enhanced to be over 60% in a broad wavelength range due to the combined effects of localized surface plasmonic resonance (LSPR), LSPR coupling and cavity resonance. Furthermore, the short current density of the bilayer solar cell reaches a high value of 15.7 mA/cm2, which is about 8.3 times that of the bilayer solar cell without the metal nanosquare arrays-dielectric-metal stucture structure. These results may provide useful guidance for future photovoltaics, energy conversion, and light harvesting devices.