US 12,281,384 B2
Low refractive index surface layers and related methods
Elena Shevchenko, Lagrange, IL (US); Diana Berman, Lemont, IL (US); and Supratik Guha, Chicago, IL (US)
Assigned to UCHICAGO ARGONNE, LLC, Chicago, IL (US)
Filed by UCHICAGO ARGONNE, LLC, Chicago, IL (US)
Filed on Jun. 20, 2023, as Appl. No. 18/211,903.
Application 18/211,903 is a division of application No. 15/649,448, filed on Jul. 13, 2017, granted, now 11,725,275.
Prior Publication US 2023/0332286 A1, Oct. 19, 2023
Int. Cl. C23C 16/40 (2006.01); C23C 16/04 (2006.01); C23C 16/455 (2006.01); C23C 16/56 (2006.01); G02B 1/111 (2015.01); G02B 1/118 (2015.01)
CPC C23C 16/40 (2013.01) [C23C 16/04 (2013.01); C23C 16/045 (2013.01); C23C 16/403 (2013.01); C23C 16/405 (2013.01); C23C 16/45525 (2013.01); C23C 16/45527 (2013.01); C23C 16/45555 (2013.01); C23C 16/56 (2013.01); G02B 1/111 (2013.01); G02B 1/118 (2013.01); G02B 2207/107 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An antireflective coated substrate comprising:
(a) a transparent material substrate;
(b) a porous metal oxide or metalloid oxide layer on the transparent material substrate;
wherein the porous metal oxide or metalloid oxide layer has an index of refraction (nc) and a thickness (dc) selected according to the following relationship:
nc=(nsnm)0.5  (I)
dc=λ0/(4nc)  (II)
wherein:
ns is the index of refraction of the transparent material of the substrate;
nm is the index of refraction of the medium through which incident light passes before passing through the formed porous metal oxide or metalloid oxide layer and the transparent material of the substrate;
λ0 is an incident wavelength to be fully transmitted through the porous metal oxide or metalloid oxide layer and the transparent material of the substrate, λ0 being a selected single wavelength in range from 250 to 3000 nm;
the index of refraction (nc) of the porous metal oxide or metalloid oxide layer is within ±0.03 units of the value of ns specified by equation (I);
the thickness (dc) of the porous metal oxide or metalloid oxide layer is within ±10% of the value of dc specified by equation (II); and
the thickness (dc) of the porous metal oxide or metalloid oxide layer is in a range from 50 to 1000 nm; and
wherein the porous metal oxide or metalloid oxide layer is formed on the substrate by:
(a) applying a block copolymer layer on a substrate, the block copolymer comprising a polar polymeric block and a non-polar polymeric block;
(b) completely immersing the block copolymer in a solvent at a temperature ranging from 55° C. to 120° C., thereby swelling the block copolymer layer and increasing the block copolymer layer thickness followed by removing at least 75% of the liquid solvent from the block copolymer layer to provide a dried, swollen, block copolymer;
(c) depositing a metal oxide or metalloid oxide layer on the polar polymeric blocks of the dried, swollen, block copolymer layer; and
(d) removing the block copolymer layer from the substrate, thereby forming the porous metal oxide or metalloid oxide layer on the substrate.