Ultralight 2D mirrors published in ACS Photonics

Reflectivity of 2D heterostructures versus metals

G. T. Papadakis, P. Narang, R. Sundararaman, N. Rivera, H. Buljan, N. Engheta and M. Soljacic, “Ultra-light Å-scale Optimal Optical Reflectors”, ACS Photonics 5, 384 (2018)

In a collaboration spanning RPI, Harvard, Caltech, MIT and Zagreb, we show that heterostructures of 2D materials, such as alternating atomic layers of graphene and hexagonal boron nitride, can exceed the reflectivity of noble metals at a fraction of the weight! Specifically, we use first principles calculations to predict carrier scattering and dielectric functions of such heterostructures, which combined with optical transfer matrix methods, allow prediction of reflectivity, plasmon modes and waveguide characteristics. We identify the optimum charge densities (doping levels) in graphene to realize maximum reflectivity in these heterostructures. These ultralight infrared mirrors could prove particularly useful in aerospace components and privacy screens for security applications.