Enhanced optical absorption of graphene-based heat mirror with tunable spectral selectivity

Graphene/Cu/graphene heat mirror with Cu thickness of 10 nm behaves like an antireflection coating (i.e., T >  80%). Whereas, at Cu thickness of 40 nm, the graphene based multilayer absorber exhibits very high optical absorption (i.e., α = 0.91). The concept of a heat mirror and a high/low/high refractive index stack was used to develop the graphene/Cu/graphene multilayer coating on quartz substrates and realize the transition from high transmittance to high absorptance.215