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US-12623901-B2 - Hierarchical silicon nanostructures, methods of making, and methods of use

US12623901B2US 12623901 B2US12623901 B2US 12623901B2US-12623901-B2

Abstract

Described herein are antireflective materials and methods of making antireflective materials. The material can include a plurality of hierarchical nanostructures on abase substrate and a total specular reflection of less than 3% at a wavelength of about 400 nm to about 1100 nm. The material can have an etched polyimide layer disposed on the superior surface of the hierarchical nanostructures. The materials can also have superhydrophobic characteristics.

Inventors

  • Peng Jiang
  • Zhuxiao GU
  • Calen Leverant

Assignees

  • UNIVERSITY OF FLORIDA RESEARCH FOUNDATION, INC.

Dates

Publication Date
20260512
Application Date
20210826

Claims (13)

  1. 1 . A method of making an antireflective material, comprising: disposing a mask comprising an array of templating nanoparticles on a top surface of a base substrate by removing the base substrate from a solution having colloidal silica nanoparticles disposed on the surface of the solution, wherein as the base substrate is withdrawn from the solution the array of templating nanoparticles is disposed on the top surface of the base substrate; etching the top surface of the base substrate; removing the templating nanoparticles, where the removal of the templating nanoparticles forms concave nanoposts; disposing a polyimide layer on the concave nanoposts; and etching the polyimide layer to form hierarchical nanocylinders comprising nanocones in concave nanoposts, wherein the base substrate and hierarchical nanocylinders are made of silicon or black silicon, and wherein the antireflective material has a water contact angle of about 130° to about 165°.
  2. 2 . The method of claim 1 , wherein the polyimide layer comprises poly (4,4′-oxydiphenylene-pyromellitimide) tape.
  3. 3 . The method of claim 1 , wherein the templating nanoparticles are silicon nanoparticles.
  4. 4 . The method of claim 1 , wherein the templating nanoparticles have a diameter of about 500 nm to 2 mm.
  5. 5 . The method of claim 1 , wherein the templating nanoparticles have a diameter of about 700 nm to 1 mm.
  6. 6 . The method of claim 1 , wherein the etching is chlorine plasma-assisted reactive ion etching.
  7. 7 . The method of claim 1 , wherein the concave nanoposts are not uniformly spaced apart from one another.
  8. 8 . The method of claim 1 , wherein the antireflective material has a height of about 200 nm to 3000 nm, wherein the concave nanoposts have a spacing of about 10 nm to 1000 nm between a pair of nanopost bases, wherein each of the nanopost bases have an average diameter of about 70 nm to 2000 nm, wherein each of the nanopost bases have an average height of about 200 nm to 3000 nm, wherein the nanocones inside the concave nanoposts can each have an average height of about 20 nm to 500 nm, and wherein the nanocones can each have a diameter of about 10 nm to 200 nm.
  9. 9 . The method of claim 1 , wherein the antireflective material has maximum specular reflection between 400 and 800 nm that is less than 1%.
  10. 10 . The method of claim 1 , wherein the antireflective material has a water contact angle of about 130° to about 165°.
  11. 11 . A material comprising: a plurality of hierarchical nanostructures on a base substrate, wherein the hierarchical nanostructures comprise concave nanoposts filled with a plurality of nanocones, wherein the base substrate and the plurality of hierarchical nanostructures are made of is silicon or black silicon, and wherein the material has a maximal specular reflection between 400 and 800 nm that is less than 3% and wherein the material has a water contact angle of about 130° to about 165°.
  12. 12 . The material of claim 11 , wherein the material has a height of about 200 nm to 3000 nm, wherein the concave nanoposts have a spacing of about 10 nm to 1000 nm between a pair of nanopost bases, wherein each of the nanopost bases have an average diameter of about 70 nm to 2000 nm, wherein each of the nanopost bases have an average height of about 200 nm to 3000 nm, wherein each of the nanocones inside the concave nanoposts can have an average height of about 20 nm to 500 nm, and wherein each of the nanocones can have a diameter of about 10 nm to 200 nm.
  13. 13 . The material of claim 11 , wherein the concave nanoposts are not uniformly spaced apart from one another.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the 35 U.S.C. § 371 national stage of PCT application having serial number PCT/US2021/047741, filed on Aug. 26, 2021. This application also claims priority to U.S. provisional application having Ser. No. 63/071,503 filed on Aug. 28, 2020, which are entirely incorporated herein by reference. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with government support under Grant No. 1562861, awarded by the National Science Foundation. The government has certain rights in the invention. BACKGROUND Materials having improved antireflective and self-cleaning properties are needed for various applications, including solar cells and surface-enhanced Raman scattering (SERS) sensors. SUMMARY Embodiments of the present disclosure provide antireflective materials, methods of making antireflective materials, and the like. An embodiment of the present disclosure includes antireflective materials that include a plurality of hierarchical nanostructures on a base substrate, where the hierarchical nanostructures include concave nanoposts. The nanoposts are filled with a plurality of nanocones. The material can have a total specular reflection of less than 3% at a wavelength of about 400 nm to about 1100 nm. The material can include an etched polyimide layer disposed on the superior surface of the hierarchical nanostructures. An embodiment of the present disclosure includes antireflective materials that include a plurality of hierarchical nanostructures on a base substrate, wherein the hierarchical nanostructures comprise concave nanoposts filled with a plurality of nanocones. An embodiment of the present disclosure also includes methods of making an antireflective material. The methods can include disposing a mask comprising an array of templating nanoparticles on a top surface of a base substrate and etching the top surface of the base substrate. The templating nanoparticles are removed, and the removal of the templating nanoparticles forms concave nanoposts. A polyimide layer can be disposed on the concave nanoposts and the polyimide layer etched to form hierarchical nanocylinders that include nanocones in concave nanoposts. Other compositions, apparatus, methods, features, and advantages will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional compositions, apparatus, methods, features and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. BRIEF DESCRIPTION OF THE DRAWINGS Further aspects of the present disclosure will be more readily appreciated upon review of the detailed description of its various embodiments, described below, when taken in conjunction with the accompanying drawings. FIG. 1 is a scanning electron microscope (SEM) image of 700 nm-SiNPs-templated hierarchical nanocylinders (hNCs) in accordance with embodiments of the present disclosure. FIGS. 2A-2H provide example SEM images of the hierarchical nanocylinders in accordance with embodiments of the present disclosure. FIG. 2A is a top view of the nanocylinders after the completion of the first etch using 1 μm SiNPs as the templating mask which are dissolved in HF. FIG. 2B is a top view of the nanocylinders with a clear boundary. FIG. 2C is a tilted (30°) view of the hierarchical nanocylinders and black silicon (BSi) surface. FIGS. 2D-2F are magnified images of hierarchical nanocylinders captured, each is more distant to the polyimide tape. FIGS. 2G and 2H are side views of the nanocylinders resulting from highly anisotropic etching. FIG. 3 provides normal-incident optical reflection spectra for plain silicon, hNCs templated from 700 nm and 1 μm SiNPs, and BSi over the visible wavelengths. Inset is a magnified view of the three antireflective samples. FIGS. 4A-4F are images taken using a CCD camera attached with a contact angle measurement unit showing contact angle measurements of various substrates treated by fluorosilane (FIG. 4A, bare silicon; FIG. 4B, hNCs etched once; FIG. 4C., hNCs templated from 1 μm SiNPs with tape; FIG. 4D, hNCs templated from 700 nm SiNPs with tape; FIG. 4E, BSi for 30 mins; FIG. 4F, BSi for 20 min. FIG. 4G is a graph comparing the contact angles of the substrates shown in FIGS. 4A-4F. FIG. 5 graphs surface-enhanced Raman scattering (SERS) on the 700 nm-templated hNCs substrate. Inset is a mapping for 10 points along a 1000 nm line randomly selected on the substrate. The drawings illustrate only example embodiments and are therefore not to be considered limiting of the scope described herein, as other equally effective embodiments are within the scope and spirit of this disclosure. DETAILED DESCRIPTION Before the present disclosure is described in greater detail, it is to be understood that this disclosure is not limited to particular embodime