  Metamaterial-based perfect absorbers promise many applica- tions. Perfect
absorption is characterized by the complete suppression of transmission and
reflection and complete dissipation of the incident energy by the absorptive
meta-atoms. A certain absorption spectrum is usually assigned to a bulk medium
and serves as a signature of the respective material. Here we show how to use
graphene flakes as building blocks for perfect absorbers. Then, an absorbing
meta-atom only consists of a molecular monolayer placed at an appropriate
distance from a metallic ground plate. We show that the functionality of such
device is intuitively and correctly explained by a Fabry-Perot model.
