Graphene-based highly efficient and broadband solar absorber

Abstract

We propose graphene-based solar absorber for broadband absorption response. The absorber is designed by sandwich graphene layer between the dielectric layer and resonator layer. The use of graphene layer improves the absorption in the dielectric layer. The design results in the form of absorption, reflection and normalised electric field are analysed for graphene-based design and simple design (without graphene layer). The design with the graphene layer is giving better absorption behaviour in the range of 100 THz to 1600 THz. The design results are also analysed for the different physical design parameters like gold resonator width (G_W), silver resonator width (S_W), gold dielectric layer height (G_H) and total structure width (W). The increase in the gold resonator and silver resonator width reduces the absorption and increase in height of gold dielectric layer increases the absorption. The designed structure is absorbing not only visible energy but also infrared energy and ultraviolet energy. The designed graphene-based broadband solar absorber is applicable in solar energy harvesting, light trapping and photovoltaic devices.