All-nitride broadband metamaterial absorbers

Perfect absorber is an important kind of electromagnetic metamaterials. In this study, all-nitride perfect broadband metamaterial absorbers were theoretically designed and studied. Nitride is used as both conducive and insulating layer materials in the absorbers. A three-layer absorber achieve a absorption performance above 90% within 640–1500 nm. A four-layer absorber, in which an additional nitride insulating layer are applied, gives a perfect absorption bandwidth between 260 and 1510 nm. In addition, the nitride absorber exhibits polarization independence at normal incidence and keeps a high absorption at large incidence angle. The results show that the all-nitride absorbers provide high absorption performance comparable to noble metal peers, and are promising alternatives in the related applications.