Terahertz Selective Active Electromagnetic Absorption Film Based on Single-layer Graphene

•CST and theoretical calculation show that the film has two absorption peaks in the terahertz band and the absorption rate is higher than 90% about 3.2 THz, which shows the good characteristics of our film.•By changing the physical parameters and applying an external bias voltage to change the Fermi level of graphene, the active tunability of the film in a wide range is achieved.•By changing the parameters, the film has five different absorption modes.•The film shows polarization independent characteristics and absorption stability at different incident angles.•It is discussed that the strong absorption is due to the electric field coupling effect of its physical structure.