Lithography-free, broadband, omnidirectional, and polarization-insensitive thin optical absorber

Abstract

We have proposed and experimentally demonstrated a lithography-free, broadband, thin optical absorber composed of planar multilayered dielectric and metal films, which can cover the total visible wavelength range with simulated and experimental absorption efficiencies higher than 90%. Moreover, the absorption is insensitive to the polarization and angle of incidence. Such a planar device is much easier to fabricate compared with other broadband absorbers with complicated structures and may have potential applications in solar energy harvesting and controllable thermal emission.