High transparency, high haze nanostructured structures
The invention relates generally to optically high transparency and high haze structures and, more particularly, to plastic, e.g., polymer, and glass structures having a sub-wavelength texture formed on a surface thereof, which is effective to impart the optical properties of high transparency and high haze to the structures. The texture is in a grass-like or needle-like form. Additionally, the optically high transparency and high haze structures may include a transparent conductor. Furthermore, the glass structures may exhibit a self-cleaning function.
1 . A method of fabricating a structure that exhibits a switchable haze from transparent to opaque, comprising:
obtaining a substrate selected from the group consisting of polymer and glass, having a top surface and an opposing bottom surface;
depositing a plurality of nanoscale polymer particles on at least one of the top surface and the opposing bottom surface of the substrate;
etching the plurality of nanoscale polymer particles to form a sub-wavelength, nano-structured polymer texture having a grass-like form comprising a plurality of blades on the at least one of the top surface and the opposing bottom surface of the substrate and;
exhibiting a switchable haze from transparent to opaque, comprising:
applying to the sub-wavelength, nano-structured polymer texture, water or a liquid having an index of refraction comparable to water, to form a transparent state; and
removing from the sub-wavelength, nano-structured polymer texture, the water or liquid having an index of refraction comparable to water, to revert to an opaque state.
2 . The method of claim 1 , wherein the etching step comprises reactive ion etching.
3 . The method of claim 2 , further comprising depositing or patterning a transparent conductor on the at least one of the top surface and the opposing bottom surface which does not have the sub-wavelength, nano-structured texture.
4 . The method of claim 1 , wherein an etch rate is tuned or controlled to correspondingly tune or control morphology of the sub-wavelength, nano-structured texture, and the switchable haze from transparent to opaque.
5 . The method of claim 1 , further comprising modifying the surface of the sub-wavelength, nano-structured texture with a molecule.
6 . The method of claim 1 , wherein the plurality of blades has a height from about 1-10 um.
7 . The method of claim 1 , wherein a distance between each of the plurality of blades is from about 100-700 nanometers.
8 . The method of claim 1 , wherein the switchable haze is greater than 80%.
9 . The method of claim 1 , further comprising depositing or patterning a transparent conductor on one of the top surface and the opposing bottom surface which does not have the sub-wavelength, nano-structured polymer texture.
10 . The method of claim 9 , wherein the transparent conductor is selected from the group consisting of metal nanowire, metal nanomesh, doped metal oxide, and combinations thereof.