At block 412, the substrate with the thin film and electrodes (the “device”) may be annealed. The device may be annealed for about 10 minutes. The device may be annealed at temperatures ranging from about room temperature to about 300 C. In a particular embodiment, the device is annealed at temperatures ranging from about 200 C to about 250 C. In an exemplary embodiment, the device is annealed at about 250 C. Annealing at elevated temperatures allows for long range diffusion, which is desirable in the design of some devices.

FIG. 5 is a flowchart 50 of exemplary steps for forming optical metamaterials with NCs. The NCs may be cadmium based (e.g., CdS, CdSe, CdTe), zinc based (e.g., ZnS, ZnSe, ZnTe), nickel based (e.g., NiFe), gold based, silver based, bismuth based, and/or lead based (e.g., PbS, PbSe, PbTe). At block 500, NCs are dispersed in a solvent (e.g., hexanes, octanes, etc.). Other suitable NC compositions, alloys, and/or core/shells will be understood by one of skill in the art.

At block 502, substrates are prepared and washed in an ultrasonicating bath. The substrate may be glass, quartz, polydimethylsiloxane (PDMS), polyethyleneterephthalate (PET), low-density polyethylene (LDPE) or any other substrate operable for use in the invention as will be recognized by one of skill in the art from the description herein. The ultrasonicating bath may consist of solvents, e.g. alkaline detergent, deionized water, hydrochloric acid, ethanol, etc. The bath may also comprise a sequence of different solvents. In an exemplary embodiment, the sequence of solvents is alkaline detergent, deionized water, about 1 M hydrochloric acid, deionized water, and ethanol.