Index-gradient structures with nanovoided materials and corresponding systems and methods

Abstract

Embodiments of the disclosure are directed to index-gradient antireflective coatings that include a differential concentration of nanovoids versus thickness of the coating. In one embodiment, an index-gradient antireflective coating may have an index of refraction that varies from a first value to that of a second material. In another embodiment, the substrate may be optically transparent, and made of, for example, polymer, glass, or ceramics. The index-gradient antireflective coating can be fabricated using a non-uniform spin-coating process, by successive thermal evaporation, or by a chemical vapor deposition (CVD) process. In another embodiment, the spin-coating process can include multiple steps that include different concentrations of monomers to solvent, different spin-speeds, or different annealing times/temperatures. Similarly, the thermal evaporation can include multiple steps that include different concentrations of monomers, initiators, solvents, and associated processing parameters. Various other methods, systems, apparatuses, and materials are also disclosed.