Glass-based substrates and methods of making the same

Abstract

Glass-based substrates have a depletion layer extending from a first major surface to a first depth from 300 nanometers to 10.0 micrometers. The depletion layer is depleted in one or more alkali metal oxide, alkaline earth metal oxide, alumina, or combinations thereof relative to a bulk. In aspects, the glass-based substrates can exhibit a porosity less than or equal to 1.0% for the first major surface and / or a cross-section perpendicular to the first major surface. In aspects, the glass-based substrates can exhibit one or more of a total reflectance from 0.1% to 2.0%, a total transmittance from 94% to 100%, a scattering from 0.1% to 5.0%, or a combination thereof. Methods of treating a glass-based substrate includes contacting the glass-based substrate with treatment solution maintained at 80°C to 180°C for from 1 hour to 168 hours to form the depletion layer.

Description

GLASS-BASED SUBSTRATES AND METHODS OF MAKINGTHE SAMECROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Serial No. 63 / 677460 filed on July 31, 2024, and claims the U.S. Provisional Application Serial No. 63 / 773026 filed on March 17, 2025, the contents of which are relied upon and incorporated herein by reference in their entirety.FIELD

[0002] The present disclosure relates generally to glass-based substrates and methods of making the same and, more particularly, to glass-based substrates having a depletion layer and methods of making the same.BACKGROUND

[0003] Glass-based substrates are commonly used, for example, in display devices, e.g., liquid crystal displays (UCDs), electrophoretic displays (EPD), organic light-emitting diode displays (OUEDs), plasma display panels (PDPs), or the like. Glass-based materials are often treated to provide aesthetic and functional characteristics based on the end -use application of the material. For example, anti- reflective and anti-glare coatings can be applied to such materials used in touchscreen products. However, such coatings can have limited durability. Also, to broaden the scope of such coatings, the coatings may need to be exceedingly complex and / or expensive. Consequently, there is a desire to provide cheaper and / or broadband anti- reflective or anti-glare functionality to glass-based substrates.SUMMARY

[0004] There are set forth herein glass-based substrates and methods of making the same having a depletion layer extending from the first major surface. Providing a depletion layer can provide enhanced optical properties, including one or more of reduced reflectance, reduced scattering, and / or increased transmittance over visual and / or infrared optical wavelengths. Without wishing to be bound by theory, the depletion thickness can roughly correspond to a maximum wavelength where theglass-based substrate with the depletion layer reliably exhibits excelled anti-reflective properties (which is supported by the results discussed with reference to FIG. 12). For example, glass-based substrates having a depletion layer with a depletion thickness of 760 nm or more (e.g., 800 nm or more, 1.0 pm or more) are expected to have anti- reflective properties over the visual spectrum (e.g., optical wavelengths from 380 nm to 760 nm, from 400 nm to 700 nm).

[0005] To the extent that all light incident on the first major surface can be accounted for through the combination of transmittance, reflectance, scattering, and absorption - for the optical wavelengths discussed in this application, it is believed that absorption is negligible for substrate thicknesses less than 1 mm. Consequently, decreasing reflectance and / or scattering is believed to increase transmittance. Also, a proxy for scattering can be estimated as 100% - (T + R), where T is transmittance and R is reflectance at a predetermined optical wavelength (or averaged over a predetermined range of optical wavelengths). Providing the depletion layer in the glass-based substrate can provide increased transmittance (e.g., greater than an untreated glass-based substrate without the depletion layer but otherwise identical greater than or equal to 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, or more), decreased reflectance, and / or decreased scattering.

[0006] As demonstrated by the Examples herein, it is the combination of pH and ionic strength that allows the treatment solution to form the depletion layer within the ranges disclosed herein. FIG. 24 demonstrates that the ionic strength of the treatment solution alone is not sufficient to produce antireflective articles. FIG. 25 demonstrates that the pH of the treatment solution alone is not sufficient to produce antireflective articles. Rather, the combination of pH and ionic strength should be selected based on the acid resistance of the glass-based substrate and the time that the treatment solution will contact the glass-based substrate. The ionic strength of the treatment solution can be from 6 to 24, from 8 to 20, or from 10 to 16. Also, the pH of the treatment solution can be from 0.3 to 3.2 or from 0.5 to 1.5.

[0007] Some example aspects of the disclosure are described below with the understanding that any of the features of the various aspects may be used alone or in combination with one another.

[0008] Aspect 1. A glass-based substrate comprising: a depletion layer extending from a first major surface to a first depth from the first major surface, the depletion layer is depleted in one or more alkali metal oxide,alkaline earth metal oxide, alumina, or combinations thereof relative to a bulk of the glass-based substrate, and the first depth is from 300 nanometers to 10.0 micrometers.

[0009] Aspect 2. The glass-based substrate of aspect 1, wherein the first depth is from 800 nanometers to 2.0 micrometers.

[0010] Aspect 3. The glass-based substrate of any one of aspects 1-2, wherein the first depth corresponds to an average depth that the depletion layer extends from the first major surface, and a depth variation of the depletion layer is from 50 nanometers to 600 nanometers.

[0011] Aspect 4. The glass-based substrate of any one of aspects 1-3, wherein the glass-based substrate exhibits a total reflectance averaged over optical wavelengths from 350 nanometers to 800 nanometers of light incident on the first major surface is from 0. 1% to 2.0%.

[0012] Aspect 5. The glass-based substrate of any one of aspects 1-3, wherein the glass-based substrate exhibits a total reflectance averaged over optical wavelengths from 800 nanometers to 2000 nanometers of light incident on the first major surface is from 0. 1% to 2.0%.

[0013] Aspect 6. The glass-based substrate of any one of aspects 1-5, wherein the glass-based substrate exhibits a total transmittance averaged over optical wavelengths from 350 nanometers to 800 nanometers is from 94% to 100%.

[0014] Aspect 7. The glass-based substrate of any one of aspects 1-5, wherein the glass-based substrate exhibits a total transmittance averaged over optical wavelengths from 800 nanometers to 2000 nanometers is from 94% to 100%.

[0015] Aspect 8. The glass-based substrate of any one of aspects 6-7, wherein the total transmittance is measured for a substrate thickness of 0.8 millimeters.

[0016] Aspect 9. The glass-based substrate of any one of aspects 1-8, wherein the glass-based substrate exhibits a scattering of the first major surface averaged over optical wavelengths from 350 nanometers to 800 nanometers from 0. 1% to 5.0%.

[0017] Aspect 10. The glass-based substrate of any one of aspects 1-8, wherein the glass-based substrate exhibits a scattering of the first major surface averaged over optical wavelengths from 350 nanometers to 800 nanometers from 0.1% to 2.0%.

[0018] Aspect 11. The glass-based substrate of any one of aspects 1-10, wherein a surface roughness Sa of the first major surface is from 0.01 nanometers to 50 nanometers.

[0019] Aspect 12. The glass-based substrate of any one of aspects 1-11, wherein a porosity of the first major surface is less than or equal to 1.0%.

[0020] Aspect 13. The glass-based substrate of any one of aspects 1-12, wherein a concentration of alumina at 200 nanometers from the first major surface is less than or equal to 10 mol%.

[0021] Aspect 14. The glass-based substrate of any one of aspects 1-12, wherein a concentration of alumina at 200 nanometers from the first major surface is less than or equal to 50% of a concentration of alumina in the bulk.

[0022] Aspect 15. The glass-based substrate of any one of aspects 1-14, wherein a concentration of alumina at 200 nanometers from the first major surface is less than or equal to 0. 1 mol%.

[0023] Aspect 16. The glass-based substrate of any one of aspects 1-14, wherein a concentration of alumina at 200 nanometers from the first major surface is less than or equal to 25% of a concentration of alumina in the bulk.

[0024] Aspect 17. The glass-based substrate of any one of aspects 1-17, wherein a concentration of the one or more alkali metal oxide at 200 nanometers from the first major surface is less than or equal to 25% of a corresponding concentration of the one or more alkali metal oxide in the bulk.

[0025] Aspect 18. The glass-based substrate of any one of aspects 1-17, wherein a concentration of the one or more alkali metal oxide at 200 nanometers from the first major surface is less than or equal to 0. 1 mol%.

[0026] Aspect 19. The glass-based substrate of any one of aspects 1-18, wherein a concentration of one or more alkaline earth metal oxides at 200 nanometers from the first major surface is less than or equal to 25% of a corresponding concentration of the one or more alkaline earth metal oxides in the bulk.

[0027] Aspect 20. The glass-based substrate of any one of aspects 1-21, wherein a concentration of chloride at 200 nanometers from the first major surface is greater than or equal to 10'3mol%.

[0028] Aspect 21. The glass-based substrate of any one of aspects 1-21, wherein a concentration of copper at 200 nanometers from the first major surface is greater than or equal to 10'4mol%.

[0029] Aspect 22. The glass-based substrate of any one of aspects 1-21, wherein a concentration of zinc at 200 nanometers from the first major surface is greater than or equal to 10'4mol%.

[0030] Aspect 23. The glass-based substrate of any one of aspects 1-22, wherein a concentration of silica at 200 nanometers from the first major surface is from 80 mol%to 100 mol%.

[0031] Aspect 24. The glass-based substrate of any one of aspects 1-23, wherein a refractive index profile of the depletion layer is continuous.

[0032] Aspect 25. The glass-based substrate of any one of aspects 1-24, wherein the glass-based substrate is substantially chemically unstrengthened.

[0033] Aspect 26. The glass-based substrate of any one of aspects 1-25, wherein a substrate thickness of the glass-based substrate is from 30 micrometers to 1 millimeter.

[0034] Aspect 27. The glass-based substrate of any one of aspects 1-26, wherein a composition of the bulk comprises: from 40 mol% to 80 mol% SiCh; from 0 mol% to 30 mol% AI2O3; from 5 mol% to 20 mol% R2O, R2O is a total amount of Li2O, Na2O, K2O, Rb2O, and CS2O; from 0 mol% to 15 mol% RO, RO is a total amount of MgO, CaO, SrO, BaO, and ZnO; from 0 mol% to 10 mol% B2O3; from 0 mol% to 15 mol% P2O5; and from 0 mol% to 5 mol% ZrO2.

[0035] Aspect 28. A consumer electronic product comprising: a housing comprising a front surface, a back surface, and a side surface; electrical components at least partially within the housing, the electrical components comprising a controller, a memory, and a display, the display at or adjacent the front surface of the housing; and a cover substrate disposed over the display, wherein at least a portion of the cover substrate or the housing comprises the glass -based substrate of any one of aspects 1-27.

[0036] Aspect 29. A method of treating a glass-based substrate comprising: contacting a first major surface of the glass-based substrate with a treatment solution maintained at a first temperature for a first period of time to form a depletion layer extending from a first major surface to a first depth from the first major surface, the first temperature is from 80°C to 180°C, depletion depth and the first period oftime is from 1 hour to 168 hours, and the first depth is from 300 nanometers to 10.0 micrometers.

[0037] Aspect 30. The method of aspect 29, wherein a pH of the treatment solution is from 0.3 to 3.2.

[0038] Aspect 31. The method of aspect 30, wherein the pH of the treatment solution is from 0.5 to 1.5.

[0039] Aspect 32. The method of any one of aspects 29-31, wherein an ionic strength of the treatment solution is from 6 to 24.

[0040] Aspect 33. The method of aspect 32, wherein the ionic strength is from 12 to 16.

[0041] Aspect 34. The method of any one of aspects 29-33, wherein the first period of time is from 6 hours to 120 hours.

[0042] Aspect 35. The method of any one of aspects 29-34, wherein treatment solution comprises one or more of copper ions or zinc ions.

[0043] Aspect 36. The method of any one of aspects 29-35, wherein the treatment solution comprises one or more of chloride ions or nitrate ions.

[0044] Aspect 37. The method of any one of aspects 29-36, wherein the treatment solution further comprises from 10'4wt% to 3 wt% of a surface agent.

[0045] Aspect 38. The method of aspect 38, wherein the surface agent comprises polyethylene glycol).

[0046] Aspect 39. The method of any one of aspects 29-38, wherein the first depth is from 800 nanometers to 2.0 micrometers.

[0047] Aspect 40. The method of any one of aspects 29-39, wherein the first depth corresponds to an average depth that the depletion layer extends from the first major surface, and a depth variation of the depletion layer is from 50 nanometers to 600 nanometers.

[0048] Aspect 41. The method of any one of aspects 29-40, wherein the glassbased substrate having the depletion layer exhibits a total reflectance averaged over optical wavelengths from 400 nanometers to 800 nanometers of light incident on the first major surface is from 0.1%to 2.0%.

[0049] Aspect 42. The method of any one of aspects 29-41, wherein the glassbased substrate having the depletion layer exhibits a total reflectance averaged over optical wavelengths from 800 nanometers to 2000 nanometers of light incident on the first major surface is from 0.1%to 2.0%.

[0050] Aspect 43. The method of any one of aspects 29-42, wherein the glassbased substrate having the depletion layer exhibits a total transmittance averaged over optical wavelengths from 400 nanometers to 800 nanometers is from 94% to 100%.

[0051] Aspect 44. The method of any one of aspects 29-42, wherein the glassbased substrate having the depletion layer exhibits a total transmittance averaged over optical wavelengths from 800 nanometers to 2000 nanometers is from 94% to 100%.

[0052] Aspect 45. The method of any one of aspects 43-44, wherein the total transmittance is measured for a substrate thickness of 0.8 millimeters.

[0053] Aspect 46. The method of any one of aspects 29-45, wherein the glassbased substrate having the depletion layer exhibits a scattering of the first major surface averaged over optical wavelengths from 400 nanometers to 800 nanometers from 0. 1% to 5.0%.

[0054] Aspect 47. The method of any one of aspects 29-46, wherein the glassbased substrate having the depletion layer exhibits a scattering of the first major surface averaged over optical wavelengths from 400 nanometers to 800 nanometers from 0. 1% to 2.0%.

[0055] Aspect 48. The method of any one of aspects 29-47, wherein a surface roughness Sa of the first major surface is from 0.01 nanometers to 50 nanometers.

[0056] Aspect 49. The method of any one of aspects 29-48, wherein a porosity of the first major surface is less than or equal to 1.0%.

[0057] Aspect 50. The method of any one of aspects 29-49, wherein the glassbased substrate having the depletion layer is substantially chemically unstrengthened.

[0058] Aspect 51. The method of any one of aspects 29-50, wherein a substrate thickness of the glass-based substrate is from 30 micrometers to 800 micrometers.

[0059] Aspect 52. The method of any one of aspects 29-38, wherein the method produces the glass-based substrate of any one of claims 1-30.

[0060] Aspect 53. The method of any one of aspects 29-52, wherein a porosity of the first major surface is less than or equal to 0.1%.

[0061] Aspect 54. The method of any one of aspects 29-53, wherein a porosity of a cross-section perpendicular to the first major surface is less than or equal to 1.0%.

[0062] Aspect 55. The method of any one of aspects 29-54, wherein a porosity of a cross-section perpendicular to the first major surface is less than or equal to 0. 1%.

[0063] Aspect 56. The method of any one of aspects 29-55, wherein a high- resolution porosity of the first major surface is less than or equal to 1 .0%.

[0064] Aspect 57. The method of any one of aspects 29-56, wherein a high- resolution porosity of the first major surface is less than or equal to 0.1%.

[0065] Aspect 58. The method of any one of aspects 29-57, wherein the first major surface has a maximum size of pores less than 10 nm no visible pores.

[0066] Aspect 59. The method of any one of aspects 29-58, wherein the glassbased substrate does not exhibit phase separation.

[0067] Aspect 60. The glass-based substrate of any one of aspects 1-27, wherein a porosity of the first major surface is less than or equal to 0. 1%.

[0068] Aspect 61. The glass-based substrate of any one of aspects 1-27 and 60 inclusive, wherein a porosity of a cross-section perpendicular to the first major surface is less than or equal to 1.0%.

[0069] Aspect 62. The glass-based substrate of any one of aspects 1-27 and 60-61 inclusive, wherein a porosity of a cross-section perpendicular to the first major surface is less than or equal to 0.1 %.

[0070] Aspect 63. The glass-based substrate of any one of aspects 1-27 and 60-62 inclusive, wherein a high-resolution porosity of the first major surface is less than or equal to 1.0%.

[0071] Aspect 64. The glass-based substrate of any one of aspects 1-27 and 60-63 inclusive, wherein a high-resolution porosity of the first major surface is less than or equal to 0.1%.

[0072] Aspect 65. The glass-based substrate of any one of aspects 1-27 and 60-64 inclusive, wherein the first major surface has a maximum size of pores less than 10 nm no visible pores.

[0073] Aspect 66. The glass-based substrate of any one of aspects 1-27 and 60-65 inclusive, wherein the glass-based substrate does not exhibit phase separation.

[0074] Aspect 67. The glass-based substrate of any one of aspects 1-27 and 60-66 inclusive, wherein a concentration of boron at 200 nanometers from the first major surface is less than or equal to 25% of a corresponding concentration of the boron in the bulk.

[0075] Throughout the disclosure, the drawings are used to emphasize certain aspects. As such, it should not be assumed that the relative size of different regions,portions, and substrates shown in the drawings are proportional to its actual relative size, unless explicitly indicated otherwise.BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The above and other features and advantages of aspects of the present disclosure are better understood when the following detailed description is read with reference to the accompanying drawings, in which:

[0077] FIG. 1 is a schematic view of an example glass-based substrate in accordance with aspects of the present disclosure;

[0078] FIG. 2 is an enlarged view 2 of FIG. 1 depicting a depletion layer in accordance with aspects of the present disclosure;

[0079] FIG. 3 is a schematic plan view of an example consumer electronic device according to aspects;

[0080] FIG. 4 is a schematic perspective view of the example consumer electronic device of FIG. 3;

[0081] FIG. 5 schematically illustrates a step in a method of making a glassbased substrate comprising reducing the thickness with an etchant;

[0082] FIG. 6 schematically illustrates a step in a method of making a glassbased substrate comprising contacting the first major surface with a treatment solution;

[0083] FIG. 7 schematically illustrates a cross-sectional view of Example 1 taken using transmission electron microscopy (TEM) in accordance with aspects;

[0084] FIG. 8 schematically illustrates concentration profiles in mol% on the vertical axis (e.g., y-axis) as a function of distance d from the first major surface in nanometers on the horizontal axis (e.g., x-axis) taken using secondary-ion massspectroscopy (SIMS) in accordance with aspects;

[0085] FIG. 9 schematically illustrates reflectance curves having reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) simulated for glass-based articles having different depths of the depletion layer in accordance with aspects;

[0086] FIG. 10 schematically illustrates reflectivity curves having reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) simulated for glass-based articleshaving different refractive index differences (e.g., surface refractive index values) in accordance with aspects;

[0087] FIG. 11 schematically illustrates a multi -part refractive index profde with refractive index on the vertical axis (e.g., y-axis) as a function of distance d from the first major surface in micrometers on the horizontal axis (e.g., x-axis) corresponding to the transmission electron microscopy (TEM) shown in FIG. 7;

[0088] FIG. 12 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) simulated for glass-based articles having different depths of the depletion layer in accordance with aspects;

[0089] FIG. 13 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) simulated for glass-based articles having different variation in the depth of the depletion layer in accordance with aspects;

[0090] FIG. 14 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) simulated for glass-based articles having different near-surface refractive index profiles in the depletion layer in accordance with aspects;

[0091] FIG. 15 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) simulated for glass-based articles having different refractive index values at the first major surface in accordance with aspects;

[0092] FIG. 16 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) simulated for glass-based articles having different refractive index profiles in the depletion layer in accordance with aspects;

[0093] FIG. 17 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition C contacted with treatment solutions having different pH values;

[0094] FIG. 18 schematically illustrates scattering in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition C contacted with treatment solutions having different pH values;

[0095] FIG. 19 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition C contacted with treatment solutions having different anions;

[0096] FIG. 20 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition C contacted with treatment solutions having different anions;

[0097] FIG. 21 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different amounts of a mineral acid;

[0098] FIG. 22 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different amounts of a mineral acid;

[0099] FIG. 23 schematically illustrates scattering in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different amounts of a mineral acid;

[0100] FIG. 24 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different cations;

[0101] FIG. 25 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different cations;

[0102] FIG. 26 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different ionic strengths;

[0103] FIG. 27 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different amounts of silica;

[0104] FIG. 28 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having silica and different ionic strengths;

[0105] FIG. 29 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different amounts of poly (vinyl alcohol);

[0106] FIG. 30 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different amounts of poly(vinyl alcohol);

[0107] FIG. 31 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having polyethylene glycol);

[0108] FIG. 32 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different amounts of poly (ethylene glycol);

[0109] FIG. 33 schematically illustrates scattering in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition B contacted with treatment solutions having different amounts of polyethylene glycol);

[0110] FIG. 34 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles havingComposition C contacted with treatment solutions having different amounts of poly (ethylene glycol);

[0111] FIG. 35 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition C contacted with treatment solutions having different amounts of polyethylene glycol);

[0112] FIG. 36 schematically illustrates scattering in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition C contacted with treatment solutions having different amounts of polyethylene glycol);

[0113] FIG. 37 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition C contacted with treatment solutions having different amounts of polyethylene glycol) in combination with a mineral acid;

[0114] FIG. 38 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition C contacted with treatment solutions having different amounts of polyethylene glycol) in combination with a mineral acid;

[0115] FIG. 39 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for various glass-based articles having Composition A-E treated for 3 days;

[0116] FIG. 40 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for various glass-based articles having Composition A-E treated for 3 days;

[0117] FIG. 41 schematically illustrates scattering in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for various glass-based articles having Composition A-E treated for 3 days;

[0118] FIG. 42 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis(e.g., x-axis) experimentally measured for glass-based articles having Composition C treated for various periods of time;

[0119] FIG. 43 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition C treated for various periods of time;

[0120] FIG. 44 schematically illustrates reflectance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition D treated for various periods of time; and

[0121] FIG. 45 schematically illustrates transmittance in % on the vertical axis (e.g., y-axis) as a function of optical wavelength in nanometers on the horizontal axis (e.g., x-axis) experimentally measured for glass-based articles having Composition D treated for various periods of time.

[0122] Throughout the disclosure, the drawings are used to emphasize certain aspects. As such, it should not be assumed that the relative size of different regions, portions, and substrates shown in the drawings are proportional to its actual relative size, unless explicitly indicated otherwise.DETAILED DESCRIPTION

[0123] Aspects will now be described more fully hereinafter with reference to the accompanying drawings in which example aspects are shown. Whenever possible, the same reference numerals are used throughout the drawings to refer to the same or like parts. However, claims may encompass many different aspects of various aspects and should not be construed as limited to the aspects set forth herein.

[0124] FIG. 1 illustrates a schematic view of a glass-based substrate 101 comprising a substrate 103 in accordance with aspects of the disclosure. Unless otherwise noted, a discussion of features of aspects of one glass-based substrate can apply equally to corresponding features of any aspects of the disclosure. For example, identical part numbers throughout the disclosure can indicate that, in some aspects, the identified features are identical to one another and that the discussion of the identified feature of one aspect, unless otherwise noted, can apply equally to the identified feature of any of the other aspects of the disclosure.

[0125] As shown in FIG. 1, the glass-based substrate 101 comprises a substrate 103 having a first major surface 105 and a second major surface 107opposite the first major surface 105. In aspects, the first major surface 105 can extend along a first plane, and / or the second major surface 107 can extend along a second plane. In further aspects, the second major surface 107 (e.g., second plane) can be substantially parallel to the first major surface 105 (e.g., first plane). As used herein, a substrate thickness 109 of the glass-based substrate 101 is defined between the first major surface 105 and the second major surface 107 as an average distance therebetween. With reference to FIG. 1, the distance between the first major surface 105 and the second major surface 107 is measured in a thickness direction 102 at a plurality of locations (e.g., at least 20 locations spaced along the width direction 106) and those measurements are averaged to calculate to the substrate thickness 109. In aspects, the substrate thickness 109 can be 10 micrometers (pm) or more, 25 pm or more, 30 pm or more, 40 pm or more, 50 pm or more, 60 pm or more, 75 pm or more, 100 pm or more, 150 pm or more, 200 pm or more, 250 pm or more, 400 pm or more, 600 pm or more, 750 pm or more, 1 millimeter (mm) or more, 2 mm or more, 5 mm or less, 3 mm or less, 2 mm or less, 1 mm or less, 900 pm or less, 800 pm or less, 600 pm or less, 400 pm or less, 250 pm or less, 200 pm or less, 180 pm or less, 160 pm or less, 140 pm or less, 120 pm or less, 100 pm or less, 80 pm or less, 60 pm or less, 50 pm or less, or 40 pm or less. In aspects, the substrate thickness 109 of the glass-based substrate 101 can be from greater than or equal to 10 pm to less than or equal to 5 mm, from greater than or equal to 25 pm to less than or equal to 3 mm, from greater than or equal to 30 pm to less than or equal to 2 mm, from greater than or equal to 60 pm to less than or equal to 1 mm, from greater than or equal to 75 pm to less than or equal to 800 pm, from greater than or equal to 100 pm to less than or equal to 600 pm, from greater than or equal to 150 pm to less than or equal to 400 pm, from greater than or equal to 200 pm to less than or equal to 250 pm, or any range or subrange therebetween. In aspects, the substrate thickness 109 of the glassbased substrate 101 can be from greater than or equal to 30 pm to less than or equal to 1 mm, from greater than or equal to 40 pm to less than or equal to 900 pm, from greater than or equal to 50 pm to less than or equal to 800 pm, from greater than or equal to 60 pm to less than or equal to 600 pm, from greater than or equal to 75 pm to less than or equal to 400 pm, from greater than or equal to 100 pm to less than or equal to 250 pm, from greater than or equal to 150 pm to less than or equal to 200 pm, or any range or subrange therebetween. In aspects, as shown, a local thickness of the glass-based substrate 101 can be substantially uniform (e.g., substantially equal tothe substrate thickness 109) across the first major surface 105 and / or the second major surface 107.

[0126] Glass-based substrates 101 can have a pencil hardness of 8H or more, for example, 9H or more. As used herein, pencil hardness is measured using ASTM D 3363-20 with standard lead graded pencils. Throughout the disclosure, the Young’s modulus of the glass-based materials is measured using the resonant ultrasonic spectroscopy technique set forth in ASTM E2001-13, titled “Standard Guide for Resonant Ultrasound Spectroscopy for Defect Detection in Both Metallic and Non-metallic Parts.” In aspects, the glass-based substrate can comprise an elastic modulus in a range from 60 GPa to 120 GPa, from 70 GPa to 100 GPa, from 72 GPa to 80 GPa, or any range or subrange therebetween.

[0127] As used herein, “glass-based” includes both glasses and glassceramics, wherein glass-ceramics have one or more crystalline phases and an amorphous, residual glass phase. A glass-based material (e.g., glass-based substrate) may comprise an amorphous material (e.g., glass) and optionally one or more crystalline materials (e.g., ceramic). Exemplary glass-based materials, which may be free of lithia or not, comprise soda lime glass, alkali aluminosilicate glass, alkali- containing borosilicate glass, alkali-containing aluminoborosilicate glass, alkali- containing phosphosilicate glass, and alkali -containing aluminophosphosilicate glass. In one or more aspects, a glass-based material may comprise, in mole percent (mol %): SiC>2 from 40 mol% to 80 mol%, AI2O3 from 5 mol% to 30 mol%, B2O3 from 0 mol% to 10 mol%, ZrCh from 0 mol% to 5 mol%, P2O5 from 0 mol% to 15 mol%, TiCE from 0 mol% to 2 mol%, R2O from 0 mol% to 20 mol%, and RO from 0 mol% to 15 mol%. As used herein, R2O refers to a total amount of alkali metal oxides (i.e., Li2O, Na2O, K2O, Rb2O, and CS2O). As used herein, RO refers to a total amount of alkaline earth oxides (i.e., MgO, CaO, SrO, and BaO) and ZnO. In aspects, a glassbased substrate may optionally further comprise from 0 mol % to 2 mol % of each of Na2SO4, NaCl, NaF, NaBr, K2SO4, KC1, KF, KBr, As2O3, Sb2O3, SnO2, Fe2O3, and manganese oxides. “Glass-ceramics” include materials produced through controlled crystallization of glass. In aspects, glass-ceramics have from 1% to 99% crystallinity (by volume). Examples of suitable glass-ceramics may include Li2O-AhO3-SiO2 system (i.e., LAS-System) glass-ceramics, MgO-AhO3-SiO2 system (i.e., MAS- System) glass-ceramics, ZnO x AI2O3xnSiO2 (i.e., ZAS system), and / or glassceramics that include a predominant crystal phase including [3-quartz solid solution, [3-spodumene, cordierite, petalite, and / or lithium disilicate. In aspects, the glass-based substrate can be substantially amorphous and / or entirely amorphous, meaning that the glass-based substrate contains less than 1 vol% or 0 vol%, respectively, of crystals.

[0128] In aspects, the glass-based substrate 101 has SiCh is the largest constituent and, as such, SiCh is the primary constituent of the glass network formed from the glass-based composition. Pure SiCh has a relatively low CTE. However, pure SiCh has a high melting point. Accordingly, if the concentration of SiCh in the glassbased composition is too high, the formability of the glass-based composition may be diminished as higher concentrations of SiCh increase the difficulty of melting the glass, which, in turn, adversely impacts the formability of the composition. If the concentration of SiCh in the glass-based composition is too low the chemical durability of the glass-based material may be diminished, and the glass-based material may be susceptible to surface damage during post-forming treatments. In aspects, the glass-based substrate can comprise SiCh in an amount of 60 mol% or more, 62 mol% or more, 63 mol% or more, 63.5 mol% or more, 64.0 mol% or more, 64.5 mol% or more, 65.0 mol% or more, 66.0 mol% or more, 67.0 mol% or more, 68.0 mol% or more, 80 mol% or less, 75 mol% or less, 72 mol% or less, 71.0 mol% or less, 70.5 mol% or less, 70.0 mol% or less, 69.5 mol% or less, 69.0 mol% or less, 68.0 mol% or less, 67.0 mol% or less, or 66.0 mol% or less. In aspects, the glass-based substrate can comprise SiCh in a range from greater than or equal to 60 mol% to less than or equal to 80 mol%, from greater than or equal to 62 mol% to less than or equal to 75 mol%, from greater than or equal to 63 mol% to less than or equal to 72 mol%, from 63.5 mol% to less than or equal to 71.0 mol%, from greater than or equal to 64.0 mol% to less than or equal to 70.5 mol%, from greater than or equal to 64.5 mol% to less than or equal to 70.0 mol%, from greater than or equal to 65.0 mol% to less than or equal to 69.5 mol%, from greater than or equal to 66.0 mol% to less than or equal to 69.0 mol%, from greater than or equal to 67.0 mol% to less than or equal to 68.0 mol%, or any range or subrange therebetween. In preferred aspects, the glass-based substrate comprises SiCh in an amount from greater than or equal to 60 mol% to less than or equal to 80 mol%, from greater than or equal to 63 mol% to less than or equal to 72 mol%, or from greater than or equal to 64.0 mol% to less than or equal to 70.0 mol%.

[0129] The glass-based substrate 101 can include AI2O3. AI2O3 may serve as a glass network former, similar to SiCh. AI2O3 may increase the viscosity of the glassbased composition due to its tetrahedral coordination in a glass melt formed from aglass-based composition, decreasing the formability of the glass-based composition when the amount of AI2O3 is too high. However, when the concentration of AI2O3 is balanced against the concentration of SiCh and the concentration of alkali oxides in the glass-based composition, AI2O3 can reduce the liquidus temperature of the glass melt, thereby enhancing the liquidus viscosity and improving the compatibility of the glass-based composition with certain forming processes. The inclusion of AI2O3 in the glass-based compositions can enable the high fracture toughness values described herein. In aspects, the glass-based substrate comprises AI2O3 in a concentration of 5 mol% or more, 7 mol% or more, 8 mol% or more, 9 mol% or more, 9.5 mol% or more, 10.0 mol% or more, 11.0 mol% or more, 12.0 mol% or more, 13.0 mol% or more, 30 mol% or less, 25 mol% or less, 20 mol% or less, 17 mol% or less, 15 mol% or less, 14.5 mol% or less, 14.0 mol% or less, 13.0 mol% or less, 12.0 mol% or less, or 11.0 mol% or less. In aspects, the glass-based substrate can comprise an amount of AI2O3 in a range from greater than or equal to 5 mol% to less than or equal to 30 mol%, from greater than or equal to 5 mol% to less than or equal to 25 mol%, from greater than or equal to 7 mol% to less than or equal to 20 mol%, from greater than or equal to 7 mol% to less than or equal to 17 mol%, from greater than or equal to 8 mol% to less than or equal to 15 mol%, from greater than or equal to 9 mol% to less than or equal to 15 mol%, from greater than or equal to 9.5 mol% to less than or equal to 14.5 mol%, from greater than or equal to 10.0 mol% to less than or equal to 14.5 mol%, from greater than or equal to 11.0 mol% to less than or equal to 14.0 mol%, from greater than or equal to 12.0 mol% to less than or equal to 13.0 mol%, or any range or subrange therebetween. In preferred aspects, the glass-based substrate comprises AI2O3 in an amount from greater than or equal to 5 mol% to less than or equal to 30 mol%, from greater than or equal to 8 mol% to less than or equal to 17 mol%, or from greater than or equal to 10 mol% to less than or equal to 14.5 mol%.

[0130] In aspects, the glass-based substrate 101 can optionally include one or more alkali metal oxides. As used herein, a total amount of alkali metal oxides R2O defined as a total amount of Li2O, Na2O, K2O, Rb2O, and CS2O. In aspects, the glassbased substrate comprises R2O in an amount of 0 mol% or more, 5 mol% or more, 10 mol% or more, 12 mol% or more, 13 mol% or more, 14.0 mol% or more, 15.0 mol% or more, 16.0 mol% or more, 17.0 mol% or more, 20 mol% or less, 18 mol% or less, 17.5 mol% or less, 17.0 mol% or less, 16.5 mol% or less, 16.0 mol% or less, 15.5 mol% or less, 15 mol% or less, 12 mol% or less, 10 mol% or less, 5 mol% or less, or1 mol% or less. In aspects, the glass-based substrate comprises an amount of R2O in a range from greater than or equal to 5 mol% to less than or equal to 25 mol%, from greater than or equal to 10 mol% to less than or equal to 20 mol%, from greater than or equal to 12 mol% to less than or equal to 18 mol%, from greater than or equal to 13 mol% to less than or equal to 17.5 mol%, from 14.0 mol% to less than or equal to 17.0 mol%, from greater than or equal to 15.0 mol% to less than or equal to 16.5 mol%, from greater than or equal to 16.0 mol% to less than or equal to 16.5 mol%, or any range or subrange therebetween. In preferred aspects, the glass-based substrate comprises Na2O in an amount from greater than or equal to 12 mol% to less than or equal to 18 mol%, from greater than or equal to 14 mol% to less than or equal to 17 mol%, or from 15.0 mol% to less than or equal to 16.5 mol%. Alternatively, the glassbased substrate can be free of alkali metal oxides R2O. In aspects, the glass-based substrate 101 can include Na2O. Na2O may improve the formability, and thereby manufacturability, of the glass-based composition. However, if too much Na2O is added to the glass-based composition, the melting point may be too high. In aspects, an amount of Na2O can be within one or more of the ranges discussed above in this paragraph for the total amount of alkali metal oxides R2O.

[0131] The glass-based substrate 101 may optionally include Li2O. In aspects, the glass-based substrate can comprise Li2O in an amount of 0.0 mol% or more, 0.1 mol% or more, 0.5 mol% or more, 1.0 mol% or more, 2.0 mol% or more, 5.0 mol% or more, 10 mol% or less, 7 mol% or less, 5 mol% or less, 2 mol% or less, 1 mol% or less, 0.5 mol% or less, or 0.2 mol% or less. In aspects, the glass-based substrate can comprise an amount of Li2O in a range from greater than or equal to 0.0 mol% to less than or equal to 10 mol%, from greater than or equal to 0.1 mol% to less than or equal to 7 mol%, from greater than or equal to 0.5 mol% to less than or equal to 5 mol%, from greater than or equal to 1.0 mol% to less than or equal to 2 mol%, or any range or subrange therebetween. In aspects, the glass-based substrate can be free of Li2O. The glass-based substrate 101 may optionally include K2O. In aspects, an amount of K2O can be within one or more of the ranges discussed above in this paragraph for Li2O. In aspects, the glass-based substrate can be free of K2O. In aspects, CS2O and / or Rb2O can be optionally present within one or more of the ranges discussed above for Li2O in this paragraph, including that the glass-based substrate can be substantially free of or free of CS2O and / or Rb2O.

[0132] In aspects, the glass-based substrate 101 can be per-alkaline, meaning that AI2O3 - R2O < 0 mol%. In further aspects, a value of AI2O3 - R2O and / or AI2O3 - Na20 can be -1 mol% or more, -2 mol% or more, -2.2 mol% or more, -2.5 mol% or more, -3.0 mol% or more, -4.0 mol% or more, -4.5 mol% or more, -5.0 mol% or more, -7 mol% or less, -6.0 mol% or more, -5.8 mol% or more, -5.5 mol% or more, -5.0 mol% or more, -4.5 mol% or more, -4.0 mol% or more, -3.0 mol% or more, or -2.5 mol% or more. In further aspects, a value of AI2O3 - R2O and / or AI2O3 - Na2O can be in a range from greater than or equal to -7 mol% to less than or equal to -1 mol%, from greater than or equal to -6.0 mol% to less than or equal to -2 mol%, from greater than or equal to -5.8 mol% to less than or equal to -2.2 mol%, from greater than or equal to -5.5 mol% to less than or equal to -2.5 mol%, from greater than or equal to -5.0 mol% to less than or equal to -3.0 mol%, from greater than or equal to -4.5 mol% to less than or equal to -4.0 mol%, or any range or subrange therebetween. In preferred aspects, AI2O3 - R2O and / or AI2O3 - Na2O can be from greater than or equal to -6.0 mol% to less than or equal to -2 mol%, or from greater than or equal to -5.8 mol% to less than or equal to greater than or equal to -2.2 mol%. Alternatively, the glass-based substrate can be per-aluminous meaning that AI2O3 - R2O > 0 mol%.

[0133] The glass-based substrate 101 can include MgO. MgO may lower the viscosity of a glass, which enhances the formability and manufacturability of the composition. The inclusion of MgO in a glass-based composition may also improve the strain point and the Young’s modulus of the glass-based composition. However, if too much MgO is added to the glass-based composition, the liquidus viscosity may be too low for compatibility with desirable forming techniques. The addition of too much MgO may also increase the density and the CTE of the glass-based composition to undesirable levels. The inclusion of MgO in the glass-based composition also helps improve the fracture toughness. In aspects, the glass-based substrate can comprise MgO in an amount of 0 mol% or more, 1 mol% or more, 2 mol% or more, 3.0 mol% or more, 3.5 mol% or more, 4.0 mol% or more, 4.5 mol% or more, 5.0 mol% or more, 6.0 mol% or more, 7.0 mol% or more, 12 mol% or less, 10 mol% or less, 7 mol% or less, 6 mol% or less, 5.5 mol% or less, 5.0 mol% or less, 4.9 mol% or less, 4.5 mol% or less, 4 mol% or less, 3 mol% or less, 2 mol% or less, 1 mol% or less, or 0.5 mol% or less. In aspects, the glass-based substrate can comprise an amount of MgO in a range from greater than or equal to 0 mol% to less than or equal to 12 mol%, fromgreater than or equal to 1 mol% to less than or equal to 10 mol%, from greater than or equal to 2 mol% to less than or equal to 7 mol%, from greater than or equal to 2 mol% to less than or equal to 6 mol%, from greater than or equal to 3.0 mol% to less than or equal to 5.5 mol%, from greater than or equal to 3.2 mol% to less than or equal to 5.0 mol%, from greater than or equal to 3.5 mol% to less than or equal to 4.9 mol%, from greater than or equal to 4.0 mol% to less than or equal to 4.5 mol%, or any range or subrange therebetween. In preferred aspects, the composition comprises MgO in an amount from greater than or equal to 2 mol% to less than or equal to 6 mol% or from greater than or equal to 3.0 mol% to less than or equal to 5.5 mol%. Alternatively, the glass-based substrate 101 can be free of MgO.

[0134] The glass-based substrate 101 described herein may include CaO. CaO may lower the viscosity of a glass, which may enhance the formability, the strain point, and the Young’s modulus. However, if too much CaO is added to the glassbased composition, the density and the CTE of the glass-based composition may increase to undesirable levels. The inclusion of CaO in the glass-based composition also improves the fracture toughness. In aspects, the glass-based substrate can comprise CaO in an amount of 0.01 mol% or more, 0.1 mol% or more, 0.3 mol% or more, 0.5 mol% or more, 0.7 mol% or more, 1.0 mol% or more, 2.0 mol% or more, 5.0 mol% or more, 7.0 mol% or more, 10 mol% or less, 9 mol% or less, 7 mol% or less, 5 mol% or less, 2 mol% or less, 1.5 mol% or less, 1.2 mol% or less, 1.0 mol% or less, or 0.7 mol% or less. In aspects, the glass-based substrate can comprise an amount of CaO in a range from greater than or equal to 0.01 mol% to less than or equal to 10.0 mol%, from greater than or equal to 0. 1 mol% to less than or equal to 9 mol%, from greater than or equal to 0.3 mol% to less than or equal to 7 mol%, from greater than or equal to 0.5 mol% to less than or equal to 5 mol%, from greater than or equal to 0.7 mol% to less than or equal to 2 mol%, from greater than or equal to 1.0 mol% to less than or equal to 1.5 mol%, or any range or subrange therebetween. In preferred aspects, the glass-based substrate comprises CaO in an amount from greater than or equal to 0.01 mol% to less than or equal to 10.0 mol% or from greater than or equal to 0.3 mol% to less than or equal to 2.0 mol%. Alternatively, in aspects, the glass-based substrate 101 can be substantially free of CaO.

[0135] As used herein, a total amount of alkaline earth oxides and ZnO (RO) refers to a total amount of MgO, CaO, SrO, BaO, and ZnO in the glass-based substrate. In aspects, RO can be within one or more of the ranges discussed above forMgO, for example, from greater than or equal to 0 mol% to less than or equal to 12 mol% or from greater than or equal to 3 mol% to less than or equal to 7 mol%. In aspects, the glass-based substrate 101 can optionally comprise SrO, BaO, and / or ZnO. In aspects, an amount of SrO, BaO, and / or ZnO can be within one or more of the ranges discussed above for the amount of CaO. Alternatively, the glass-based substrate can be free of one or more of MgO, SrO, BaO, ZnO, and / or RO altogether. In further aspects, the glass-based substrate can be substantially free and / or free of each of SrO, BaO, and / or ZnO.

[0136] In aspects, the glass-based substrate can optionally comprise P2O5 and / or B2O3 in a range from greater than or equal to 0 mol% to less than or equal to 10 mol%, from greater than or equal to 0 mol% to less than or equal to 9.8 mol%, from greater than or equal to 0 mol% to less than or equal to 9.5 mol%, from greater than or equal to 0.1 mol% to less than or equal to 9.0 mol%, from greater than or equal to 0.1 mol% to less than or equal to 8 mol%, from greater than or equal to 0.1 mol% to less than or equal to 7 mol%, from greater than or equal to 0.5 mol% to less than or equal to 5 mol%, from greater than or equal to 1 mol% to less than or equal to 3 mol%, or any range or subrange therebetween. Unless otherwise indicated, as used herein, the term “free” does not require absolute precision nor atomic-scale accuracy, but rather “free” means that the component may be present in the final glass-based composition in very small amounts (e.g., as a contaminant, such as less than 0.1 mol%) that could be practically obtained by a reasonable practitioner, which does include 0.0 mol% in some aspects. For example, the inclusion of ZrCU in the glassbased composition may result in the formation of undesirable zirconia inclusions in the glass-based material, due at least in part to the low solubility of ZrO? in the glassbased material. Also, the inclusion of Ta2Os, HfCU La2C>3, and / or Y2O3 may increase the cost of raw materials associated with the glass-based substrate.

[0137] In aspects, the glass-based substrate 101 can comprise from 40 mol% to 80 mol% SiC>2, from 5 mol% to 30 mol% AI2O3, from 0 mol% to 20 mol% R2O, from 0 mol% to 15 mol% RO, and optionally from 0 mol% to 10 mol% of one or more ofZrO2, B2O3, and / or P2O5. In further aspects, the glass-based substrate 101 can comprise from 60 mol% to 70 mol% SiO2, from 10 mol% to 17 mol% AI2O3, from 0 mol% to 20 mol% R2O, from 0 mol% to 12 mol% RO, and optionally from 0 mol% to 10 mol% of one or more of ZrO2, B2O3, and / or P2O5. In further aspects, the glassbased substrate can comprise from 63 mol% to 72 mol% SiO2, from 10 mol% to 17mol% AI2O3, from 10 mol% to 20 mol% R2O, from 0 mol% to 5 mol% RO, and optionally from 0 mol% to 10 mol% of one or more of ZrO2, B2O3, and / or P2O5. Alternatively, in further aspects, the glass-based substrate can comprise from 63 mol% to 72 mol% SiO2, from 10 mol% to 17 mol% AI2O3, from 0 mol% to 5 mol% R2O, from 5 mol% to 12 mol% RO, and optionally from 0 mol% to 10 mol% of one or more of ZrO2, B2O3, and / or P2O5.

[0138] In aspects, glass-based materials (including amorphous materials) can be substantially chemically unstrengthened. As used herein, substantially chemically unstrengthened refers to a substrate comprising either no depth of layer, no depth of compression, a depth of layer in a range from 0% to 5% of the substrate thickness, or a depth of compression in a range from 0% to 5% of the substrate thickness. Alternatively, the glass-based materials (e.g., glass-based substrate) can be chemically strengthened. Alternatively or additionally, the glass-based substrate can be thermally tempered and / or mechanically strengthened (e.g., lamination with materials having different coefficients of thermal expansion). As used herein, the term “chemically strengthened” may refer to a material that has been chemically strengthened, for example, through ion exchange of larger ions for smaller ions in the surface of the substrate. Chemically strengthening may comprise an ion exchange process, where ions in a surface layer are replaced by-or exchanged with-larger ions having the same valence or oxidation state. Chemical strengthening can form a compressive stress region that extends into a portion of the corresponding substrate. As used herein, depth of compression means the depth at which the stress in the chemically-strengthened substrates and / or portions described herein changes from compressive stress to tensile stress. Depth of compression may be measured by a surface stress meter or a scattered light polariscope (SCALP, wherein values reported herein were made using SCALP-5 made by Glasstress Co., Estonia) depending on the ion exchange treatment and the thickness of the article being measured. Where the stress in the substrate and / or portion is generated by exchanging potassium ions into the substrate, a surface stress meter, for example, the FSM-6000 (Orihara Industrial Co., Ltd. (Japan)), is used to measure depth of compression. Unless specified otherwise, compressive stress (including surface CS) is measured by surface stress meter (FSM) using commercially available instruments, for example the FSM-6000, manufactured by Orihara. Surface stress measurements rely upon the accurate measurement of the stress optical coefficient (SOC), which is related to thebirefringence of the glass. Unless specified otherwise, SOC is measured according to Procedure C (Glass Disc Method) described in ASTM standard C770-16, entitled “Standard Test Method for Measurement of Glass Stress-Optical Coefficient,” the contents of which are incorporated herein by reference in their entirety. Where the stress is generated by exchanging sodium ions into the substrate, and the article being measured is thicker than about 400 pm, SCALP is used to measure the depth of compression and central tension (CT). Where the stress in the substrate and / or portion is generated by exchanging both potassium and sodium ions into the substrate and / or portion, and the article being measured is thicker than about 400 pm, the depth of compression and CT are measured by SCALP. Without wishing to be bound by theory, the exchange depth of sodium may indicate the depth of compression while the exchange depth of potassium ions may indicate a change in the magnitude of the compressive stress (but not the change in stress from compressive to tensile). The refracted near-field (RNF; the RNF method is described in U.S. Patent No. 8,854,623, entitled “Systems and methods for measuring a profile characteristic of a glass sample”, which is incorporated herein by reference in its entirety) method also may be used to derive a graphical representation of the stress profile. When the RNF method is utilized to derive a graphical representation of the stress profile, the maximum central tension value provided by SCALP is utilized in the RNF method. The graphical representation of the stress profile derived by RNF is force balanced and calibrated to the maximum central tension value provided by a SCALP measurement. As used herein, “depth of layer” (DOL) means the depth that the ions have exchanged into the substrate and / or portion (e.g., sodium, potassium). Through the disclosure, when the maximum central tension cannot be measured directly by SCALP (as when the article being measured is thinner than about 400 pm) the maximum central tension can be approximated by a product of a maximum compressive stress and a depth of compression divided by the difference between the thickness of the substrate and twice the depth of compression, wherein the compressive stress and depth of compression are measured by FSM. Throughout the disclosure, an absolute value of compressive stress is reported as compressive stress, and an absolute value of central tensile stress is reported as central tensile stress.

[0139] As shown in FIG. 2, the glass-based substrate 101 comprises a depletion layer 205 extending to a depletion depth 203 from the first major surface 105, where the depletion thickness 209 is the average distance that the depletion layerextends from the first major surface 105 (see average depletion depth 203). Although FIG. 2 only shows the depletion layer 205 extending from the first major surface 105, it is to be understood that another depletion layer can be present at (e.g., extending from) the second major surface that can be similar to (e.g., having aspects within one or more of the ranges discussed herein) and / or identical to the depletion layer 205 extending from the first major surface 105. The depletion layer can be a chemically altered surface layer, for example, having one or more of the aspects discussed below. In aspects, the depletion layer 205 can be depleted in one or more of an alkali metal oxide, an alkaline earth metal oxide, alumina, or combinations thereof relative to a bulk of the glass-based substrate 101. For example, the one or more of an alkali metal oxide and / or an alkaline earth metal oxide can be depleted in the depletion layer such that an amount in the depletion layer is less than or equal to 25% of a corresponding concentration of the one or more of an alkali metal oxide and / or an alkaline earth metal oxide in the bulk; and / or alumina can be depleted such that an amount of alumina in the depletion layer is less than or equal to 50% of a corresponding concentration of alumina in the bulk. Additionally or alternatively, the depletion layer can comprise a concentration of alumina in the depletion layer (e.g., at 200 nm from the first major surface or an average concentration) can be less than or equal to 0.1 mol%; the depletion layer can comprise a concentration of one or more alkaline earth metals in the depletion layer (e.g., at 200 nm from the first major surface or an average concentration) can be less than or equal to 0.1 mol%; and / or the depletion layer can comprise a concentration of alumina in the depletion layer (e.g., at 200 nm from the first major surface or an average concentration) can be less than or equal to 0.1 mol%. Additionally or alternatively, the depletion layer can comprise one or more ions associated with a treatment solution used to form the depletion layer (discussed below), for example, one or more of copper, zinc, and / or chloride. It has been observed that a normalized concentration within the depletion layer can have up to 5 wt% of the one or more components from a treatment solution. For example, an amount of zinc, copper, and / or chloride in the depletion layer (e.g., at 200 nm from the first major surface or an average concentration) can be greater than or equal to 10'4mol%, greater than or equal to 5xl0'4mol%, greater than or equal to 10'3mol%, or greater than or equal to 5 x 10'3mol%. In aspects, the depletion layer 205 can be enriched in silica relative to the bulk (e.g., the depletion layer can be enriched by 10 mol% or more silica relative to the bulk). It is to be understood that the apparentenrichment of silica in the depletion layer is due to the leaching of other components (e.g., alumina, alkali metals, alkaline earth metals) from the depletion layer. For example, a maximum silica concentration in the depletion layer can be from 10 mol% more than the bulk to 99 mol%, from 70 mol% to 97 mol%, from 72 mol% to 95 mol%, from 72 mol% to 94 mol%, from 75 mol% to 93 mol%, from 77 mol% to 92 mol%, from 80 mol% to 91 mol%, from 82 mol% to 90 mol%, from 84 mol% to 88 mol%, or any range or subrange therebetween. As used herein, a “bulk” of the glassbased substrate and a corresponding composition refers to a portion of glass-based substrate away from the surfaces of the glass-based substrate and the composition of that portion. As used herein, compositions are determined using secondary ion mass spectrometry (SIMS) (discussed below). In aspects, the bulk composition can be measured at a location surrounding a midplane of the glass-based substrate positioned equidistant from the first major surface and the second major surface. For example, any depletion layer can be removed (e.g., by etching or mechanical polishing) so that the bulk composition can be more directly measured. In aspects, the bulk composition can be measured at a deepest location measured from the first major surface by SIMS that is at least 100 nanometers deeper than the depletion layer extends. In further aspects, a composition measured at a location surrounding the midplane can be substantially identical and / or identical to a composition at a location 100 nanometers (or deeper) from the first major surface than the depletion layer extends.

[0140] In aspects, the depletion thickness 209 of the depletion layer 205 (e.g., depletion depth 203) can be 200 nanometer (nm) or more, 250 nm or more, 300 nm or more, 450 nm or more, 600 nm or more, 760 nm or more, 800 nm or more, 900 nm or more, 1.0 pm or more, 1.1 pm or more, 1.2 pm or more, 1.4 pm or more, 1.5 pm or more, 1.6 pm or more, 1.8 pm or more, 2.0 pm or more, 2.2 pm or more, 2.5 pm or more, 3.0 pm or more, 4.0 pm or more, 5.0 pm or more, 6.0 pm or more, 8.0 pm or more, 10.0 pm or less, 8.0 pm or less, 6.0 pm or less, 5.0 pm or less, 4.0 pm or less, 3.0 pm or less, 2.5 pm or less, 2.4 pm or less, 2.3 pm or less, 2.2 pm or less, 2.1 pm or less, 2.0 pm or less, 1.8 pm or less, 1.7 pm or less, 1.6 pm or less, 1.5 pm or less, 1.4 pm or less, 1.3 pm or less, 1.2 pm or less, 1.1 pm or less, 1.0 pm or less, 900 nm or less, or 800 nm or less. In aspects, the depletion thickness 209 of the depletion layer 205 (e.g., average depletion depth 203) can be from greater than or equal to 200 nm to less than or equal to 10.0 pm, from greater than or equal to 250 nm to less than or equal to than or equal to 8.0 pm, from greater than or equal to 300 nm to less thanor equal to 6.0 qm, from greater than or equal to 450 nm to less than or equal to 5.0 qm, from greater than or equal to 600 nm to less than or equal to 4.0 qm, from greater than or equal to 760 nm to less than or equal to 3.0 qm. from greater than or equal to 800 nm to less than or equal to 2.5 qm, from greater than or equal to 900 nm to less than or equal to 2.4 qm, from greater than or equal to 1.0 qm to less than or equal to 2.3 qm, from greater than or equal to 1.2 qm to less than or equal to 2.2 qm, from greater than or equal to 1.5 qm to less than or equal to 2.1 qm, from greater than or equal to 1.8 qm to less than or equal to 2.0 qm, or any range or subrange therebetween. In aspects, the depletion thickness 209 of the depletion layer 205 (e.g., average depletion depth 203) can be less than or equal to 2.5 pm, for example, from greater than or equal to 200 nm to less than or equal to 2.5 pm, from greater than or equal to 250 nm to less than or equal to than or equal to 2.4 qm, from greater than or equal to 300 nm to less than or equal to 2.3 qm, from greater than or equal to 450 nm to less than or equal to 2.2 qm, from greater than or equal to 600 nm to less than or equal to 2. 1 qm, from greater than or equal to 760 nm to less than or equal to 2.0 qm, from greater than or equal to 800 nm to less than or equal to 2.0 qm, from greater than or equal to 900 nm to less than or equal to 1.9 nm, from greater than or equal to 1.0 qm to less than or equal to 1.8 qm, from greater than or equal to 1.1 qm to less than or equal to 1.7 nm, from greater than or equal to 1.2 qm to less than or equal to 1.6 nm, from greater than or equal to 1.3 qm to less than or equal to 1.5 qm, from greater than or equal to 1.4 qm to less than or equal to 1.5 qm, or any range or subrange therebetween. Without wishing to be bound by theory, the depletion thickness can roughly correspond to a maximum wavelength where the glass-based substrate with the depletion layer reliably exhibits excelled anti-reflective properties (which is supported by the results discussed with reference to FIG. 12). For example, glassbased substrates having a depletion layer with a depletion thickness of 760 nm or more (e.g., 800 nm or more, 1.0 qm or more) are expected to have anti-reflective properties over the visual spectrum (e.g., optical wavelengths from 380 nm to 800 nm, from 400 nm to 760 nm, or combinations thereof). In aspects, the depletion thickness 209 of the depletion layer 205 (e.g., average depletion depth 203) can be 760 nm or more, for example, in a range from greater than or equal to 760 nm to less than or equal to 10.0 qm, from greater than or equal to 800 nm to less than or equal to 8.0 qm, from greater than or equal to 900 nm to less than or equal to 6.0 qm, from greater than or equal to 1.0 qm to less than or equal to 4.0 qm, from greater than or equal to1.1 qm to less than or equal to 3.0 qm. from greater than or equal to 1.2 pm to less than or equal to 2.5 qm, from greater than or equal to 1.3 qm to less than or equal to2.2 qm, from greater than or equal to 1.4 qm to less than or equal to 2.0 qm, from greater than or equal to 1.5 qm to less than or equal to 1.8 qm, from greater than or equal to 1.6 qm to less than or equal to 1.7 qm, or any range or subrange therebetween. In preferred aspects, the depletion thickness 209 of the depletion layer 205 (e.g., average depletion depth 203) can be from greater than or equal to 300 nm to less than or equal to 10.0 qm, from greater than or equal to 800 nm to less than or equal to 2.5 qm, or from greater than or equal to 1.2 qm to less than or equal to 2.0 qm.

[0141] Throughout the disclosure, the thickness of the depletion layer is determined using transmission electron microscopy (TEM). To facilitate imaging a thin lamella of the surface including the depletion layer was taken by focused ion beam (FIB) thinning. As used herein, thickness measurements are performed using a 200 keV STEM high-angle annular dark-field (HAADF). FIG. 7 schematically shows a TEM image of an exemplary glass-based article. As shown, the depletion layer 715 has a markedly different color and appearance than the bulk 703 of the glass-based substrate. As discussed herein, the depletion layer can have a different refractive density and / or density due to the relative depletion (e.g., alkali metal oxides, alkaline earth metals, alumina) relative to the bulk. It is to be understood that a thickness of the depletion layer can be estimated using other methods including ellipsometry, interferometry (e.g., white light interferometry), and secondary-ion mass- spectrometry (SIMS), the measured thickness from TEM is used as the definitive value of thickness herein.

[0142] As shown in FIG. 7, a depletion depth 709 of the depletion layer 715 can refer to the average distance (see dashed line 713) between the first major surface 705 and the interface 711 between the depletion layer 715 and the bulk 703. Also, as shown, a location of the interface 711 between the depletion layer 715 and the bulk 703 (in a direction of the depletion depth 709) can vary, for example, between extrema 716 and 718. As used herein, a depth variation 719 in the depletion depth (corresponding to a variation in the interface 711) refers to a distance in the direction of the depletion depth 709 between extrema 716 and 718 (i.e., maximum depth and minimum depth, respectively). The interface 711 can be fitted with a spline to remove any outliers or aberrations in the measured image. In aspects, the depth variation 719can be 50 nm or more, 70 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, 450 nm or more, 500 nm or more, 600 nm or less, 550 nm or less, 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, or 250 nm or less. In aspects, the depth variation 719 can be greater than or equal to 50 nm to less than or equal to 600 nm, from greater than or equal to 70 nm to less than or equal to 550 nm, from greater than or equal to 100 nm to less than or equal to 500 nm, from greater than or equal to 150 nm to less than or equal to 450 nm, from greater than or equal to 200 nm to less than or equal to 400 nm, from greater than or equal to 300 nm to less than or equal to 400 nm, or any range or subrange therebetween. As discussed with reference to FIG. 11, the depth variation 719 can correspond an effective gradient in refractive index (see region 1125), for example, between a bulk refractive index 1116 of the bulk 703 and an average refractive index 1118 of the depletion layer 715. This region 1125 is an effective gradient as variation in the interface 711 (see FIG. 7) is averaged across the glass-based article for a given depth from the first major surface with more of the bulk contributing to this average going from the minimum depth 716 (point 1118 - 100% depletion layer) to the maximum depth 718 (point 1116 - 0% depletion layer). Simulations of an effective refractive index between the depletion layer (due to the variation depth of the interface) in FIG. 10 show that a smaller difference in refractive index (e.g., curve 915) has lower reflectance than larger differences in refractive index. Further, as shown in FIG. 13, a simulated depletion layer with a depth variation of 100 nm (curve 1311) and 200 nm (curve 1313) have the largest reflectance and variation in reflectance whereas the other depth variations (400 nm to 600 nm in curves 1315 and 1317, respectively) have lower reflectance values. Consequently, providing a depth variation of 200 nm or more can enable reduced reflectance (e.g., enhanced anti-reflective properties) for those compositions. However, it is believed that reduced reflectance can be achieved for a depth variation as low as 50 nm when the glass-based material is more acid resistant. Also, no detectable porosity is seen in the cross-sectional view of shown in FIG. 7.

[0143] Throughout the disclosure, a composition of the depletion layer and the bulk is quantified by secondary-ion mass-spectroscopy (SIMS). Throughout the disclosure, SIMS was performed using a time-of-flight SIMS (ToF-SIMS) M6 instrument (available from IONTOF GmbH) with a dual beam configuration. The TOF-SIMS M6 instrument is equipped with a Nanoprobe50 bismuth source (30 kilo-electronVolts (keV) Bi3+primary ion beam) with a current of about 0.1 pA for mass spectrometry and a cesium sputter source (2 keV Cs sputter source) with a current of about 120 nA. The bismuth primary ion beam defined an aperture of 400 pm and was operated with a cycle time of 200 ps and a 25 ns pulse width. The sputter beam was configured to form a 300 pm by 300 pm sputter “crater,” and the analysis beam was configured to impinge a 50 pm by 50 pm area centered in the sputter “crater.” Each analysis frame with the primary ion beam comprised a 64x64 pixel raster over a 50 pm by 50 pm area, and each analysis frame was alternated with 1 second of sputtering with the Cs ion beam. Charge compensation was achieved using an electron flood gun operating at 20 eV electron energy. The chamber was evacuated to a pressure of at least 5 x 10'7Pascals (5 x 10'9millibar) before being brought to and maintained at a pressure of 6 x 10'5Pascals (6 x 10'7millibar) using argon flooding. The detected counts were converted to molar amounts using a predetermined composition of the bulk. The composition of the bulk is determined by: X-ray fluorescence and comparison with standard samples for alumina, phosphorous, alkaline earth metals, transition metals (e.g., ZnO, TiCh, Fe2O3, SnCh), sodium oxide, and potassium oxide; an amount of B2O3 is measured using inductively coupled plasma (ICP) methods; an amount of lithium oxide (Li2O) is measured using flame emission spectroscopy; and an amount of SiCE is taken as the balance of material (i.e., 100% - materials measured using X-ray fluorescence, ICP, and flame emission spectroscopy), and then the composition is converted from wt% to mol%. The depth from the first major surface can be confirmed by measuring the depth that a center of the sputter crater is recessed from the first major surface (e.g., compared to a pre-sputtering measurement), where the thickness can be estimated through ellipsometry, profilometry (e.g., white-light interferometry, atomic force microscopy (AFM) or definitively measured using TEM (as discussed above). The inventors have observed that the thickness of the depletion layer roughly corresponds to a location where the concentration profile is at a value equal to the mean of the bulk concentration and a surface concentration (measured at 1 nm from the first major surface).

[0144] The following paragraphs recite concentrations of components at a specific distance (e.g., 200 nm, 500 nm, or 700 nm) from the first major surface (and ratios of such concentrations relative to a concentration in bulk), which is applicable when the depletion layer extends at least 100 nm deeper than that distance (e.g., depletion layer extending to at least 300 nm for the recited concentrations at 200 nmto be applicable). As discussed above, the depletion of other components (relative to the bulk glass) can make a local composition of the depletion appear to be enriched in silica (relative to the bulk glass). In aspects, a concentration of silica at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be greater than the corresponding silica concentration of the bulk by 10 mol% or more, 12 mol% or more, 15 mol% or more, 17 mol% or more, 20 mol% or more, 22 mol% or more, 25 mol% or more, 27 mol% or more, 30 mol% or more, 40 mol% or less, 35 mol% or less, 32 mol% or less, 30 mol% or less, 27 mol% or less, 25 mol% or less, 22 mol% or less, 20 mol% or less, 17 mol% or less, or 15 mol% or less. In aspects, a concentration of silica at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be greater than the corresponding silica concentration of the bulk by an amount from greater than or equal to 10 mol% to less than or equal to 40 mol%, from greater than or equal to 12 mol% to less than or equal to 35 mol%, from greater than or equal to 15 mol% to less than or equal to 32 mol%, from greater than or equal to 17 mol% to less than or equal to 30 mol%, from greater than or equal to 20 mol% to less than or equal to 27 mol%, from greater than or equal to 22 mol% to less than or equal to 25 mol%, or any range or subrange therebetween. In aspects, a concentration of silica at a distance (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) within the depletion layer can be 70 mol% or more, 72 mol% or more, 75 mol% or more, 77 mol% or more, 80 mol% or more, 82 mol% or more, 84 mol% or more, 86 mol% or more, 88 mol% or more, 90 mol% or more, 91 mol% or more, 92 mol% or more, 93 mol% or more, 100 mol% or less, 99 mol% or less, 98 mol% or less, 97 mol% or less, 96 mol% or less, 95 mol% or less, 94 mol% or less, 93 mol% or less, 92 mol% or less, 91 mol% or less, 90 mol% or less, 89 mol% or less, 88 mol% or less, 87 mol% or less, 86 mol% or less, 85 mol% or less, 83 mol% or less, or 80 mol% or less. In aspects, a concentration of silica at a distance (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) within the depletion layer can be in a range from greater than or equal to 70 mol% to less than or equal to 100 mol%, from greater than or equal to 72 mol% to less than or equal to 98 mol%, from greater than or equal to 75 mol% to less than or equal to 96 mol%, from greater than or equal to 77 mol% to less than or equal to 95 mol%, from greater than or equal to 80 mol% to less than or equal to 94 mol%, from greater than or equal to 80 mol% to less than or equalto 93 mol%, from greater than or equal to 82 mol% to less than or equal to 92 mol%, from greater than or equal to 84 mol% to less than or equal to 91 mol%, from greater than or equal to 86 mol% to less than or equal to 90 mol%, from greater than or equal to 87 mol% to less than or equal to 88 mol%, or any range or subrange therebetween.

[0145] As discussed above, the depletion layer can be depleted in alumina relative to the bulk. In aspects, a difference between the concentration of alumina in the bulk minus a concentration of alumina at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can 5 mol% or more, 8 mol% or more, 10 mol% or less, 11 mol% or more, 12 mol% or more, 13 mol% or more, 14 mol% or more, 15 mol% or more, 20 mol% or less, 18 mol% or less, 15 mol% or less, 14 mol% or less, 13 mol% or less, 12 mol% or less, or 11 mol% or less. In aspects, a difference between the concentration of alumina in the bulk minus a concentration of alumina at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be in a range from greater than or equal to 5 mol% to less than or equal to 20 mol%, from greater than or equal to 8 mol% to less than or equal to 18 mol%, from greater than or equal to 10 mol% to less than or equal to 15 mol%, from greater than or equal to 11 mol% to less than or equal to 14 mol%, from greater than or equal to 12 mol% to less than or equal to 13 mol%, or any range or subrange therebetween. In aspects, a concentration of alumina at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration), as a percentage of a concentration of alumina in the bulk, can be 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 1% or more, 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, or 40% or more. In aspects, a concentration of alumina at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration), as a percentage of a concentration of alumina in the bulk, can be in a range from greater than or equal to 1% to less than or equal to 50%, from greater than or equal to 5% to less than or equal to 40%, from greater than or equal to 10% to less than or equal to 30%, from greater than or equal to 15% to less than or equal to 25%, from greater than or equal to 15% to less than or equal to 20%, or any range or subrange therebetween. In aspects, a concentration of alumina at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be lessthan or equal to 1.0 mol%, less than or equal to 0.5 mol%, less than or equal to 0.2 mol%, less than or equal to 0.1 mol% (e.g., 0.10 mol%), less than or equal to 0.05 mol%, less than or equal to 0.02 mol%, or less than or equal to 0.01 mol%.

[0146] As discussed above, the depletion layer can be depleted in one or more alkali metal oxides relative to the bulk. The following discussion will focus on sodium oxide (Na2O), although the ranges can apply to a total amount of alkali metal oxides (R2O), or other alkali metal oxides if they are present in amounts greater than 0.5 mol% in the bulk. In aspects, a concentration of Na2O (and / or R2O) at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration), as a percentage of a corresponding concentration (e.g., Na2O or R2O) in the bulk, can be 33% or less, 25% or less, 22% or less, 20% or less, 18% or less, 15% or less, 10% or less, 8% or less, 5% or less, 1% or more, 3% or more, 5% or more, 10% or more, 12% or more, 15% or more, or 18% or more. In aspects, a concentration of Na2O (and / or R2O) at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration), as a percentage of a corresponding concentration (e.g., Na2O or R2O) in the bulk, can be in a range from greater than or equal to 1% to less than or equal to 33%, from greater than or equal to 1% to less than or equal to 25%, from greater than or equal to 3% to less than or equal to 22%, from greater than or equal to 5% to less than or equal to 20%, from greater than or equal to 10% to less than or equal to 18%, from greater than or equal to 12% to less than or equal to 15%, or any range or subrange therebetween. In aspects, a difference between the concentration of Na2O (and / or R2O) in the bulk minus a corresponding concentration (e.g., Na2O or R2O) at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be 1 mol% or more, 2 mol% or more, 3 mol% or more, 4 mol% or more, 5 mol% or more, 6 mol% or more, 7 mol% or more, 8 mol% or more, 9 mol% or more, 10 mol% or less, 8 mol% or less, 7 mol% or less, 6 mol% or less, 5 mol% or less, 4 mol% or less, or 3 mol% or less. In aspects, a difference between the concentration of Na2O (and / or R2O) in the bulk minus a corresponding concentration (e.g., Na2O or R2O) at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be in a range from greater than or equal to 1 mol% to less than or equal to 10 mol%, from greater than or equal to 2 mol% to less than or equal to 8 mol%, from greater than or equal to 3 mol% to less than or equal to 7 mol%, fromgreater than or equal to 4 mol% to less than or equal to 6 mol%, from greater than or equal to 5 mol% to less than or equal to 6 mol%, or any range or subrange therebetween. In aspects, a concentration of Na20 (and / or R2O) at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be 1.0 mol% or less, 0.5 mol% or less, 0.2 mol% or less, 0.1 mol% or less (e.g., 0.10 mol% or less), 0.05 mol% or less, 0.02 mol% or less, or 0.01 mol% or less.

[0147] As discussed above, the depletion layer can be depleted in one or more alkaline earth metal oxides relative to the bulk. The following discussion will focus on magnesium oxide (MgO), although the ranges can apply to a total amount of alkaline metal oxides (RO), or other alkaline metal oxides (e.g., CaO, SrO, BaO) if they are present in amounts greater than 0.5 mol% in the bulk. In aspects, a concentration of MgO (and / or CaO and / or RO) at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration), as a percentage of a corresponding concentration (e.g., MgO, CaO, and / or RO) in the bulk, can be 33% or less, 25% or less, 22% or less, 20% or less, 18% or less, 15% or less, 10% or less, 1% or more, 3% or more, 5% or more, 10% or more, 12% or more, 15% or more, or 18% or more. In aspects, a concentration of and / or CaO and / or RO at a location within the depletion layer at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration), as a percentage of a corresponding concentration (e.g., MgO, CaO, or RO) in the bulk, can be in a range from greater than or equal to 1% to less than or equal to 33%, from greater than or equal to 1% to less than or equal to 25%, from greater than or equal to 3% to less than or equal to 22%, from greater than or equal to 5% to less than or equal to 20%, from greater than or equal to 10% to less than or equal to 18%, from greater than or equal to 12% to less than or equal to 15%, or any range or subrange therebetween. In aspects, a difference between the concentration of MgO (and / or CaO and / or RO) in the bulk minus a corresponding concentration (e.g., MgO, CaO, or RO) at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be 1 mol% or more, 2 mol% or more, 3 mol% or more, 4 mol% or more, 5 mol% or more, 6 mol% or more, 7 mol% or more, 8 mol% or more, 9 mol% or more, 10 mol% or less, 8 mol% or less, 7 mol% or less, 6 mol% or less, 5 mol% or less, 4 mol% or less, or 3 mol% or less. In aspects, a difference between the concentration ofMgO (and / or CaO and / or RO) in the bulk minus a corresponding concentration (e.g., MgO, CaO, or RO) at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be in a range from greater than or equal to 1 mol% to less than or equal to 10 mol%, from greater than or equal to 2 mol% to less than or equal to 8 mol%, from greater than or equal to 3 mol% to less than or equal to 7 mol%, from greater than or equal to 4 mol% to less than or equal to 6 mol%, from greater than or equal to 5 mol% to less than or equal to 6 mol%, or any range or subrange therebetween. In aspects, a concentration of MgO (and / or CaO and / or RO) at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be 1.0 mol% or less, 0.5 mol% or less, 0.2 mol% or less, 0.1 mol% or less (e.g., 0.10 mol% or less), 0.05 mol% or less, 0.02 mol% or less, or 0.01 mol% or less.

[0148] As used herein, “surface roughness” means the surface roughness Sa, which is an arithmetical mean of the absolute deviations of a surface profile from an average position in a direction normal to the surface of the test area. Surface roughness Sa is calculated using a surface profile measured for a 2 pm by 2 pm test area using laser confocal microscopy with a resolution of at least 256 by 256 for the test area. The surface roughness Sa of the first major surface was measured without any coating thereon. In aspects, the surface roughness Sa of the first major surface of the glass-based substrate (with the depletion layer extending from the first major surface) can be 0.01 nm or more, 0.1 nm or more, 0.2 nm or more, 0.3 nm or more, 0.5 nm or more, 0.7 nm or more, 1.0 nm or more, 15 nm or more, 2.0 nm or more, 5.0 nm or more, 10 nm or more, 50 nm or less, 40 nm or less, 30 nm or less, 25 nm or less, 20 nm or less, 15 nm or less, 10 nm or less, 5.0 nm or less, 2.0 nm or less, 1.0 nm or less, 0.7 nm or less, or 0.5 nm or less. In aspects, the surface roughness Sa of the first major surface of the glass-based substrate (with the depletion layer extending from the first major surface) can be from greater than or equal to 0.01 nm to less than or equal to 50 nm, from greater than or equal to 0. 1 nm to less than or equal to 50 nm, from greater than or equal to 0.2 nm to less than or equal to 40 nm, from greater than or equal to 0.3 nm to less than or equal to 30 nm, from greater than or equal to 0.5 nm to less than or equal to 25 nm, from greater than or equal to 0.7 nm to less than or equal to 20 nm, from greater than or equal to 1.0 nm to less than or equal to 15 nm, from greater than or equal to 1.5 nm to less than or equal to 10 nm, from greater thanor equal to 2.0 nm to less than or equal to 5.0 run, or any range or subrange therebetween.

[0149] Throughout the disclosure, the porosity of the glass-based substrate is determined by analyzing an SEM image. As used herein, the porosity is determined from SEM images at 5,000 times magnification, where at least 20% of each SEM image is analyzed, and the results of analyzing seven (7) SEM images are averaged to determine the porosity. In aspects, a porosity of the glass-based substrate (e.g., first major surface) can be 0.0% or more, 0.1% or more, 0.2% or more, 0.3% or more, 0.4% or more, 0.5% or more, 0.7% or more, 1.0% or less, 0.8% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, or 0.1% or less. In aspects, a porosity of the glass-based substrate can be from 0.0% to 1.0%, from 0.1% to 0.8%, from 0.2% to 0.6%, from 0.3% to 0.5%, from 0.3% to 0.4%, or any range or subrange therebetween. In preferred aspects, the porosity of the glass-based substrate (e.g., first major surface) can be from 0.0% to 1.0%, from 0.0% to 0.2%, or from 0.0% to 0.1%. In aspects, the measured porosity of the glass-based substrate (e.g., first major surface) can be 0.0% (i.e., no detectable porosity). In aspects, the porosity of the glass-based substrate with the depletion layer can be substantially equal to (e.g., within 0.1%) a porosity of another glass-based substrate without the depletion layer but otherwise identical to the glass-based substrate in accordance with aspects of the present disclosure.

[0150] In aspects, although not shown, a coating can be disposed over the first major surface and / or the second major surface of the glass-based substrate. In even further aspects, a coating thickness of the coating can be 0.1 pm or more, 1 pm or more, 5 pm or more, 10 pm or more, 15 pm or more, 20 pm or more, 25 pm or more, 40 pm or more, 50 pm or more, 60 pm or more, 70 pm or more, 80 pm or more, 90 pm or more, 200 pm or less, 100 pm or less, 50 pm or less, 30 pm or less, 25 pm or less, 20 pm or less, 20 pm or less, 15 pm or less, or 10 pm or less. In further aspects, the coating thickness of the coating can range from 0.1 pm to 200 pm, from 1 pm to 100 pm, from 10 pm to 100 pm, from 20 pm to 100 pm, from 30 pm to 100 pm, from 40 pm to 100 pm, from 50 pm to 100 pm, from 60 pm to 100 pm, from 70 pm to 100 pm, from 80 pm to 100 pm, from 90 pm to 100 pm, from 0.1 pm to 50 pm, from 1 pm to 50 pm, from 10 pm to 50 pm, or any range or subrange therebetween.

[0151] In aspects, the coating can comprise a polymeric coating. In further aspects, the polymeric coating can comprise one or more of an ethylene-acid copolymer, a polyurethane-based polymer, an acrylate resin, and a mercapto-ester resin. Example aspects of ethylene-acid copolymers include ethylene-acrylic acid copolymers, ethylene -methacrylic acid copolymers, and ethylene -acrylic-methacrylic acid terpolymers (e.g., Nucrel (TM) (DuPont (TM))), ionomers of ethylene acid copolymers (e.g., Surlyn (TM) (DuPont (TM))), and ethylene -acrylic acid copolymer amine dispersions (e.g., Aquacer (TM) (BYK (TM))). Example aspects of polyurethane-based polymers include aqueous modified polyurethane dispersions (e.g., Eleglas (TM) (Axalta (TM))). In further aspects, the polymeric coating can comprise ethylene -acrylic acid copolymers and ethylene-methacrylic acid copolymers, which may be ionomerized to form ionomer resins through neutralization of the carboxylic acid residue with typically alkali metal ions, for example sodium, and potassium and also zinc. Such ethylene -acrylic acid and ethylene-methacrylic acid ionomers may be dispersed within water and coated onto the substrate to form an ionomer coating. Alternatively, such acid copolymers may be neutralized with ammonia which, after coating and drying liberates the ammonia to reform the acid copolymer as the coating. By providing a coating comprising a polymeric coating, the glass-based substrate can comprise low energy fracture.

[0152] In aspects, the coating, if provided, may also comprise one or more of an easy-to-clean coating, a low-friction coating, an oleophobic coating, a diamondlike coating, a scratch-resistant coating, or an abrasion-resistant coating. A scratchresistant coating may comprise an oxynitride, for example, aluminum oxynitride or silicon oxynitride with a thickness of 500 micrometers or more. In such aspects, the abrasion-resistant layer may comprise the same material as the scratch-resistant layer. Alternatively, the coating can be 50 nm or less, 20 nm or less, or 10 nm or less. In aspects, a low friction coating may comprise a highly fluorinated silane coupling agent, for example, an alkyl fluorosilane with oxymethyl groups pendant on the silicon atom. In such aspects, an easy-to-clean coating may comprise the same material as the low friction coating. In other aspects, the easy-to-clean coating may comprise a protonatable group, for example an amine, for example, an alkyl aminosilane with oxymethyl groups pendant on the silicon atom. In such aspects, the oleophobic coating may comprise the same material as the easy-to-clean coating. Inaspects, a diamond-like coating comprises carbon and may be created by applying a high voltage potential in the presence of a hydrocarbon plasma.

[0153] The transmittance and reflectance values reported herein are measured using a Cary (TM) 7000 Series UV-VIS NIR Spectrophotometer (Agilent (TM)) with a measurement interval of 1 nm and a measurement rate of 600 nm / min. In aspects, an “optically transparent material” or an “optically clear material” can have an average transmittance of 75% or more, 80% or more, 85% or more, or 90% or more, 92% or more, 93% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more in the wavelength range of 400 nm to 800 nm through a 0.8 mm thick piece of the material. The average transmittance in the wavelength range of 400 nm to 800 nm is calculated by measuring the transmittance of whole number wavelengths from 400 nm to 800 nm and averaging the measurements. In aspects, the glass-based substrate can be optically transparent. In aspects, the glass-based substrate can comprise an average transmittance (averaged over optical wavelengths from 400 nm to 800 nm) of 80% or more, 90% or more, 91% or more, 92.0% or more, 92.2% or more, 92.5% or more, 92.8% or more, 93.0% or more, 99% or less, 96% or less, 95% or less, or 94% or less. In aspects, the glassbased substrate 101 can comprise an average transmittance (averaged over optical wavelengths from 400 nm to 800 nm) in a range from 80% to 100%, from 90% to 99%, from 90% to 98%, from 91% to 97%, from 92.0% to 96%, from 92.2% to 95%, from 92.5% to 94%, from 92.8% to 93%, or any range or subrange therebetween. In further aspects, the glass-based substrate 101 can comprise an average transmittance (averaged over optical wavelengths from 400 nm to 800 nm) greater than or equal to 94.0% (e.g., 94%), for example, from greater than or equal to 94.0% to less than or equal to 100%, from greater than or equal to 95.0% to less than or equal to 99%, from greater than or equal to 95.5% to less than or equal to 98.5%, from greater than or equal to 96.0% to less than or equal to 98%, from greater than or equal to 96.5% to less than or equal to 97%, or any range or subrange therebetween. Alternatively or additionally, an average transmittance averaged over optical wavelengths in the infrared spectrum from 800 nm to 2000 nm (and / or from 1000 nm to 2400 nm, or from 1000 nm to 2000 nm) can be within one or more of ranges discussed above in this paragraph (e.g., from greater than or equal to 94.0% to less than or equal to 100%). Providing the depletion layer in the glass-based substrate can provide increased transmittance (e.g., greater than an untreated glass-based substrate withoutthe depletion layer but otherwise identical greater than or equal to 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, or more), decreased reflectance, and / or decreased scattering.

[0154] As used herein, haze refers to transmission haze that is measured through the first major surface 105 in accordance with ASTM D1003-21 at 0° relative to a direction normal to the first major surface 105. Haze is measured using a BYK (TM) Haze-Gard Dual (BYK Gardner). A CIE D65 illuminant is used as the light source for illuminating the glass-based substrate 101. Haze values reported herein are measured through a substrate comprising a thickness of 0.8 mm with the light incident on the first major surface 105 being measured as it exits the first major surface 105. In further aspects, the haze of the glass-based substrate 101 can be 5% or less, 2% or less, 1% or less, 0.8% or less, 0.5% or less, or 0.3% or less. In further aspects, the haze of the glass-based substrate 101 can be in a range from 0.01% to 5%, from 0.05% to 2%, from 0.1% to 1%, from 0.1% to 0.8%, from 0.2% to 0.5%, or any range or subrange therebetween.

[0155] In aspects, the glass-based substrate 101 can comprise a reflectance of light incident on the first major surface 105 (having the depletion layer extending therefrom). Unless otherwise specified, reflectance refers to average reflectance that is calculated by averaging reflectance measurements taken at whole number wavelengths from 400 nm to 800 nm. As used herein, reflectance is measured in accordance with ASTM F 1252-21 at an angle of 8° relative to a direction normal to the surface. Throughout the disclosure, a direction normal to the first major surface105 is defined relative to a first plane, where the first plane is taken as a least-squares fit to the portions of the first major surface 105. If the substrate is non-planar, the direction normal to the textured surface is relative to a plane fit to the 50 pm x 50 pm region of the surface where the light is incident.

[0156] In aspects, an average reflectance (averaged over optical wavelengths from 400 nm to 800 nm of light incident on the first major surface) of the glass-based substrate 101 can be less than or equal to 5.0%, less than or equal to 4.0%, less than or equal to 3.0%, less than or equal to 2.0%, less than or equal to 1.8%, less than or equal to 1.5%, less than or equal to 1.2%, less than or equal to 1.0%, less than or equal to 0.8%, less than or equal to 0.6%, less than or equal to 0.5%, less than or equal to 0.4%, less than or equal to 0.3%, less than or equal to 0.2%, less than or equal to 0.1%, greater than or equal to 0.0%, greater than or equal to 0.1%, greater than or equal to 0.1%, greater than or equal to 0.2%, greater than or equal to 0.3%,greater than or equal to 0.4%, greater than or equal to 0.5%, greater than or equal to 0.6%, greater than or equal to 0.7%, greater than or equal to 0.8%, greater than or equal to 0.9%, greater than or equal to 1.0%, greater than or equal to 1.2%, greater than or equal to 1.5%, greater than or equal to 1.7%, or greater than or equal to 2.0%. In aspects, an average reflectance (averaged over optical wavelengths from 400 nm to 800 nm of light incident on the first major surface) of the glass-based substrate 101 can be in a range from greater than or equal to 0.0% to less than or equal to 5.0%, from greater than or equal to 0.1% to less than or equal to 4.0%, from greater than or equal to 0.2% to less than or equal to 3.0%, from greater than or equal to 0.3% to less than or equal to 2.0%, from greater than or equal to 0.4% to less than or equal to 1.7%, from greater than or equal to 0.5% to less than or equal to 1.5%, from greater than or equal to 0.6% to less than or equal to 1.2%, from greater than or equal to 0.7% to less than or equal to 1.0%, or any range or subrange therebetween. In preferred aspects, when considering reflectance contributions from both major surfaces (e.g., when there is a first depletion layer extending from the first major surface and a second depletion layer extending from the second major surface), the average reflectance (averaged over optical wavelengths from 400 nm to 800 nm of light incident on the first major surface) of the glass-based substrate 101 can be from greater than or equal to 0.0% to less than or equal to 5.0%, from greater than or equal to 0.1% to less than or equal to 2.0%, or from 0.2% to less than or equal to 1.0%. Also, reflectance measurements can be taken without contributions from the surface opposite the incident light (e.g., second major surface opposite the first major surface when light is incident on the first major surface), for example, by blocking the reflectance from the opposite surface. Without wishing to be bound by theory, it is believed that reflectance contributions from just the first major surface may be about 50% or less than the reflectance measured when considering contributions from the entire glass-based substrate (e.g., both the first major surface and the second major surface). For example, when considering just reflectance from the first major surface, the average reflectance (averaged over optical wavelengths from 400 nm to 800 nm of light incident on the first major surface) of the glass-based substrate 101 can be from greater than or equal to 0.0% to 2.0%, from greater than or equal to 0.1% to 1.0%, from greater than or equal to 0.2% to less than or equal to 0.5%, or combinations thereof.

[0157] In aspects, an average reflectance averaged over optical wavelengths from 800 nm to 2000 nm (and / or from 1000 nm to 2400 nm, or from 1000 nm to 2000 nm) of light incident on the first major surface can be within one or more of the ranges discussed above in the previous paragraph (e.g., from greater than or equal to 0.0% to less than or equal to 5.0%, from greater than or equal to 0.1% to less than or equal to 2.0%, or from 0.2% to less than or equal to 1.0%). When considering reflectance contributions from both major surfaces (e.g., when there is a first depletion layer extending from the first major surface and a second depletion layer extending from the second major surface), the average reflectance averaged over optical wavelengths from 800 nm to 2000 nm (and / or from 1000 nm to 2400 nm, or from 1000 nm to 2000 nm) of light incident on the first major surface of the glassbased substrate 101 can be within one or more of the ranges discussed above in the previous paragraph (e.g., from greater than or equal to 0.0% to less than or equal to 5.0%, from greater than or equal to 0.1% to less than or equal to 2.0%, or from 0.2% to less than or equal to 1.0%). When considering just reflectance from the first major surface, the average reflectance averaged over optical wavelengths from 800 nm to 2000 nm (and / or from 1000 nm to 2400 nm, or from 1000 nm to 2000 nm) of light incident on the first major surface of the glass-based substrate 101 can be within one or more of the ranges discussed above in the previous paragraph (e.g., from greater than or equal to 0.0% to less than or equal to 2.0%, from greater than or equal to 0. 1% to less than or equal to 1.0%, or from 0.2% to less than or equal to 0.5%).

[0158] Unless otherwise indicated, “scattering” refers to average scattering that is calculated by averaging scattering measurements taken at whole number wavelengths from 400 nm to 800 nm. As used herein scattering S was calculated based on the transmittance T and reflectance R values (measured as described above) using the approximation: S% = 100% - (T% + R%) for each optical wavelength. In aspects, an average scattering (averaged over optical wavelengths from 400 nm to 800 nm of light incident on the first major surface) of the glass-based substrate 101 can be within one or more of the ranges discussed above for average reflectance (e.g., from greater than or equal to 0.0% to less than or equal to 5.0%, from greater than or equal to 0.1% to less than or equal to 2.0%, or from 0.2% to less than or equal to 1.0%). In aspects, the average scattering averaged over optical wavelengths from 800 nm to 2000 nm (and / or from 1000 nm to 2400 nm, or from 1000 nm to 2000 nm) of light incident on the first major surface of the glass-based substrate 101 can be within oneor more of the ranges discussed above for reflectance (e.g., from greater than or equal to 0.0% to less than or equal to 5.0%, from greater than or equal to 0.1% to less than or equal to 2.0%, or from 0.2% to less than or equal to 1.0%).

[0159] Without wishing to be bound by theory, it is believed that all light incident on the first major surface can be accounted for through the combination of transmittance, reflectance, scattering, and absorption. For the optical wavelengths discussed in this application, it is believed that absorption is negligible for substrate thicknesses less than 1 mm. Consequently, decreasing reflectance and / or scattering is believed to increase transmittance. Also, a proxy for scattering can be estimated as 100% - (T + R), where T is transmittance and R is reflectance at a predetermined optical wavelength (or averaged over a predetermined range of optical wavelengths).

[0160] Throughout the disclosure, refractive index of the glass-based substrate is measured in accordance with ASTM El 967- 19, where the first wavelength comprises 589 run. This refractive index largely reflects the refractive index of the bulk of the glass-based substrate (excluding the depletion layer). However, it is difficult to measure a refractive index profile of the depletion layer. Consequently, a refractive index profile of the depletion layer is approximated experimentally using an observed optical density in TEM images (see FIGS. 7 and 11), which can be averaged over locations with the same distance from the first major surface to obtain an averaged refractive index profile. Alternatively, a refractive index can be approximated using optical simulations (discussed below) using a one-portion model and / or a three-portion model for the refractive index of the simulated depletion layer, where the parameters of the model(s) are optimized to match the experimentally measured properties (e.g., transmittance spectrum, reflectance spectrum, scattering spectrum, and / or optical density profile). For either of these approximations of the refractive index profile, the refractive index profile can be continuous throughout the depletion layer. As used herein, continuous means that there is no change of greater than 10% over a 10 nm section of the depletion layer (averaged over locations with the same distance from the first major surface). Simulations indicate that the depletion layer can function as long as there are not discontinuities within the depletion layer that could otherwise cause reflection (or scattering). However, in aspects, a surface coating can be applied to the first major surface without significantly impacting the optical properties of the depletion layer.

[0161] Aspects of the disclosure can comprise a consumer electronic product. The consumer electronic product can comprise a front surface, a back surface, and side surfaces. The consumer electronic product can further comprise electrical components at least partially within the housing. The electrical components can comprise a controller, a memory, and a display. The display can be at or adjacent to the front surface of the housing. The display can comprise a liquid crystal display (LCD), an electrophoretic display (EPD), an organic light-emitting diode (OLED) display, or a plasma display panel (PDP). The consumer electronic product can comprise a cover substrate disposed over the display. In aspects, at least one of a portion of the housing or the cover substrate comprises the glass-based substrate discussed throughout the disclosure. The consumer electronic product can comprise a portable electronic device, for example, a smartphone, a tablet, a wearable device, or a laptop.

[0162] The glass-based substrate disclosed herein may be incorporated into another article, for example, an article with a display (or display articles) (e.g., consumer electronics, including mobile phones, tablets, computers, navigation systems, wearable devices (e.g., watches), and the like), architectural articles, transportation articles (e.g., automotive, trains, aircraft, sea craft, etc.), appliance articles, or any article that may benefit from some transparency, scratch-resistance, abrasion resistance or a combination thereof. An exemplary article incorporating any of the glass-based substrate 101 disclosed herein is shown in FIGS. 3-4. Specifically, FIGS. 3-4 show a consumer electronic device 300 including a housing 302 having front 304, back 306, and a side surface(s) 308. Although not shown, the consumer electronic device can comprise electrical components that are at least partially inside or entirely within the housing. For example, electrical components include at least a controller, a memory, and a display. As shown in FIGS. 3-4, the display 310 can be at or adjacent to the front surface of the housing 302. The consumer electronic device can comprise a cover substrate 312 at or over the front surface of the housing 302 such that it is over the display 310. In aspects, at least one of the cover substrate 312 or a portion of housing 302 may include any of the glass-based substrates disclosed herein.

[0163] Aspects of methods of making the glass-based substrate 101 illustrated in FIGS. 1-2, in accordance with aspects of the disclosure, will be discussed with reference to the example method steps illustrated in FIGS. 5-6. Whilemethods discussed below use a treatment solution after etching the substrate to form the depletion layer, it is to be understood that the depletion layer can be formed by the depletion solution alone. Also, the substrate can be chemically, thermally, and / or mechanically strengthened prior to contact with the treatment solution. As discussed herein, the composition and / or content of the treatment solution is not limited to the treatment solutions exemplified in the Examples section below. Without wishing to be bound by theory, it is believed that the composition of the glass-based substrate, a composition (e.g., presence of components and / or concentrations of components) in an etching solution (for etching the initial glass-based substrate) and / or a treatment solution and any additional treatments can alter (e.g., increase, decrease, not form, from) the status and / or properties of a resulting depletion layer (if any).

[0164] In a first step of methods of the disclosure, as shown in FIGS. 5-6, methods can start with providing an initial glass-based substrate 511. In aspects, the initial glass-based substrate 511 may be provided by purchase or otherwise obtaining a substrate or by forming the initial glass-based substrate. In aspects, the initial glassbased substrate 511 can comprise a glass-based material. In further aspects, a composition of the initial glass-based substrate 511 can be within one or more of the ranges discussed above for the composition of the glass-based substrate. In further aspects, initial glass-based substrate can be provided by forming them with a variety of ribbon forming processes, for example, slot draw, down-draw, fusion down-draw, up-draw, press roll, redraw, or float. In further aspects, glass-based substrates comprising ceramic crystals can be provided by heating a glass-based substrate to crystallize one or more ceramic crystals. The initial glass-based substrate 511 may comprise an initial first major surface 523 and an initial second major surface 525 opposite the initial first major surface 523. In further aspects, an initial thickness 527 of the initial glass-based substrate 511 (defined as an average distance between the initial first major surface 523 and the initial second major surface 525) can be within one or more of the ranges discussed above and / or may be within 5 pm of the final thickness (e.g., substrate thickness 109) (i.e., greater than the final thickness by from 0.1 pm to 5 pm or from 0.5 pm to 4 pm). Alternatively, in further aspects, an initial thickness 527 of the initial glass-based substrate 511 (defined as an average distance between the initial first major surface 523 and the initial second major surface 525) can be greater than the resulting final thickness (e.g., substrate thickness 109) by 5 pm or more, 10 pm or more, 15 pm or more, 20 pm or more, 25 pm or more, 30 pm ormore, 40 pm or more, or 50 pm or more (e.g., from 5 pm to 250 pm, from 10 pm to 200 pm, from 15 pm to 150 pm, from 20 pm to 100 pm, from 25 pm to 75 pm, from 30 pm to 50 pm, or any range or subrange therebetween). In further aspects, the initial first major surface 523 and / or the initial second major surface 525 can extend along a plane. In aspects, the initial glass-based substrate 511 can have a composition within one or more of the ranges discussed above for the glass-based substrate 101. In aspects, initial glass-based substrate 511 and / or the resulting glass-based substrate 101 can be substantially chemically unstrengthened. In aspects, as discussed above, the initial glass-based substrate can be chemically strengthened, thermally tempered, and / or mechanically strengthened.

[0165] Methods can comprise etching the initial glass-based substrate 511 to reduce a thickness (e.g., initial thickness 527) of the initial glass-based substrate 511 to form at least an intermediate first major surface 513 and the intermediate thickness 517, as shown in FIG. 5. In aspects, as shown, etching the initial glass-based substrate 511 can comprise contacting the initial first major surface 523 and / or the initial second major surface 525 with an etchant 503 to form the intermediate first major surface 513 and / or the intermediate second major surface 515. In further aspects, as shown, the etching (e.g., contact with the etchant 503) can remove material of the initial glass-based substrate 511 from the initial first major surface 523 and / or the initial second major surface 525 can reduce the initial thickness 527 to the intermediate thickness 517. In even further aspects, the intermediate thickness 517 can be within 5 pm of (e.g., from 0 pm to 5 pm greater than) the substrate thickness 109 of the resulting glass-based substrate 101. For example, a thickness removed from the initial glass-based substrate by etching with the etchant can be within one or more of the thickness ranges discussed in the previous paragraph. In further aspects, as shown in FIG. 5, etching the initial glass-based substrate 511 can comprise immersing the initial glass-based substrate 511 in the etchant 503 that is contained in an etchant bath 501. Alternatively, etching the initial glass-based substrate 511 can comprise spraying the etchant 503 on the initial glass-based substrate 511, for example, in a vertical top spray etching process including the method described in WO2023 / 278223A1, which is incorporated by reference herein in its entirety. In aspects, the etchant 503 can comprise hydrofluoric acid (HF). In further aspects, the etchant can additionally include one or more mineral acids (e.g., nitric acid, hydrochloric acid, phosphoric acid, and / or sulfuric acid) in addition to HF. Also, it isto be understood that a buffered HF solution (including NH4F and / or NH4HF) can form a different surface composition than using pure HF and that both surface compositions can be different from that of using HF with a mineral acid. Also, a temperature of the etchant, a concentration of the component(s) in the etchant, and an etching time can influence the thickness and / or surface composition of the resulting glass-based substrate. In aspects, a temperature of the etchant 503 can be 20°C or more, 22°C or more, 25°C or more 28°C or more, 30°C or more, 40°C or less, 35°C or less, 30°C or less, 28°C or less, 25°C or less, or 23°C or less. In aspects, a temperature of the etchant 503 can range from 20°C to 40°C, from 20°C to 35 °C, from 20°C to 30°C, from 20°C to 28°C, from 20°C to 25°C, from 22°C to 23°C, or any range or subrange therebetween.

[0166] In aspects, as shown in FIG. 6, methods can proceed to contacting at least the intermediate first major surface 513 with a treatment solution 603 to form the first major surface 105 and the glass-based substrate 101 (see FIG. 1) with at least the depletion layer extending from the first major surface. In further aspects, as shown, the intermediate second major surface 515 can also be contacted with the treatment solution 603. In further aspects, as shown, the glass-based substrate (e.g., initial glassbased substrate 511) can be immersed in the treatment solution 603 that is contained in a treatment bath 601. In further aspects, the treatment solution 603 can remove (e.g., dissolve and / or displace) any residual material from the etchant from the glassbased substrate. In further aspects, the treatment solution 603 can be agitated (e.g., ultrasonicated) to further facilitate treatment (e.g., rinsing) of the surfaces of the glassbased substrate.

[0167] In further aspects, the treatment solution 603 can comprise a treatment temperature and / or be in contact with the glass-based substrate (e.g., initial glass-based substrate 511) for a treatment period of time. In further aspects, sonication can be applied for at least half of the rinsing period of time, for example, the entire first period of time. In further aspects, the treatment period of time can be 1 hour or more, 2 hours or more, 4 hours or more, 6 hours or more, 12 hours or more, 18 hours or more, 24 hours or more, 36 hours or more, 48 hours or more, 60 hours or more, 72 hours or more, 168 hours or less, 144 hours or less, 120 hours or less, 96 hours or less, 84 hours or less, 72 hours or less, 60 hours or less, 48 hours or less, 36 hours or less, 30 hours or less, 24 hours or less, 18 hours or less, 12 hours or less, 8 hours or less, 6 hours or less, 4 hours or less, or 2 hours or less. In further aspects, the treatmentperiod of time can range from greater than or equal to 1 hour to less than or equal to 168 hours, from greater than or equal to 2 hours to less than or equal to 144 hours, from greater than or equal to 4 hours to less than or equal to 120 hours, from greater than or equal to 6 hours to less than or equal to 96 hours, from greater than or equal to 12 hours to less than or equal to 84 hours, from greater than or equal to 18 hours to less than or equal to 72 hours, from greater than or equal to 24 hours to less than or equal to 60 hours, from greater than or equal to 36 hours to less than or equal to 48 hours, or any range or subrange therebetween. In preferred aspects, the treatment period of time can range from greater than or equal to 1 hour to less than or equal to 168 hours, from 6 hours to 144 hours, or from 12 hours to 96 hours.

[0168] In further aspects, the treatment temperature can be 80°C or more, 90°C or more, 100°C or more, 110°C or more, 120°C or more, 130°C or more, 140°C or more, 150°C or more, 180°C or less, 170°C or less, 160°C or less, 150°C or less, 140°C or less, 130°C or less, 120°C or less, 110°C or less, or 100°C or less. In further aspects, the treatment temperature can be from greater than or equal to 80°C to less than or equal to 180°C, from greater than 90°C to less than or equal to 170°C, from greater than or equal to 100°C to less than or equal to 160°C, from greater than or equal to 110°C to less than or equal to 150°C, from greater than or equal to 120°C to less than or equal to 140°C, from greater than or equal to 120°C to less than or equal to 130°C, or any range or subrange therebetween.

[0169] As used herein, a pH of the treatment solution is measured in accordance with ASTM E70-90 at 25 °C with standard solutions extending down to a pH of at least 0.3. In further aspects, the treatment solution 603 can comprise a pH of 3.2 or less, 3.0 or less, 2.7 or less, 2.5 or less, 2.3 or less, 2.0 or less, 1.7 or less, 1.5 or less, 1.2 or less, 1.0 or less, 0.7 or less, or 0.5 or less, 0.3 or more, 0.5 or more, 0.7 or more, 1.0 or more, 1.2 or more, 1.5 or more, 1.7 or more, 2.0 or more, 2.2 or more, 2.5 or more, 2.7 or more, or 3.0 or more. In further aspects, the pH of the treatment solution 603 can be greater than or equal to 0.3 to less than or equal to 3.2, from greater than or equal to 0.3 to less than or equal to 3.0, from greater than or equal to 0.5 to less than or equal to 2.7, from greater than or equal to 0.5 to less than or equal to 2.5, from greater than or equal to 0.7 to less than or equal to 2.2, from greater than or equal to 0.7 to less than or equal to 2.0, from greater than or equal to 1.0 to less than or equal to 2.0, from greater than or equal to 1.2 to less than or equal to 1.7, from greater than or equal to 1.2 to less than or equal to 1.5, or any range or subrangetherebetween. In preferred aspects, the pH of the treatment solution can be from greater than or equal to 0.3 to less than or equal to 3.2 or from greater than or equal to 0.5 to less than or equal to 1.5.

[0170] As used herein, ionic strength Z is defined as half of the sum of products between a molar concentration of an ion (zi) and the charge of the ion (zi) squared for all of the ions in solution: Z = A S CiZi2. In further aspects, an ionic strength Z of the treatment solution can be 6 or more, 8 or more, 10 or more, 12 or more, 13 or more, 14 or more, 15 or more, 16 or more, 18 or more, 20 or more, 24 or less, 20 or less, 18 or less, 16 or less, 15 or less, 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, or 8 or less. In further aspects, an ionic strength Z of the treatment solution can be greater than or equal to 6 to less than or equal to 24, from greater than or equal to 8 to less than or equal to 22, from greater than or equal to 10 to less than or equal to 20, from greater than or equal to 11 to less than or equal to 18, from greater than or equal to 12 to less than or equal to 16, from greater than or equal to 13 to less than or equal to 15, from greater than or equal to 13 to less than or equal to 14, or any range or subrange therebetween. In preferred aspects, the ionic strength Z of the treatment solution can be from greater than or equal to 6 to less than or equal to 24, from greater than or equal to 8 to less than or equal to 20, or from greater than or equal to 10 to less than or equal to 16. As demonstrated by the Examples herein, it is the combination of pH and ionic strength that allow the treatment solution to form the depletion layer within the ranges disclosed herein.

[0171] It is believed that the combination of pH and ionic strength of the treatment solution (as set forth in the previous paragraphs) can generate the depletion layer at the appropriate temperature and in contact with the glass-based substrate for sufficient time. In further aspects, the treatment solution can comprise essentially one component that achieves both the pH and the ionic strength of the treatment solution. For example, the treatment solution can comprise a copper-containing compound (e.g., copper chloride or copper nitrate). Alternatively, in further aspects, the treatment solution can comprise a first component to achieve the pH and a second component to achieve the ionic strength. For example, the treatment solution can comprise a zinc -containing compound (e.g., zinc chloride or zinc nitrate) that primarily contributes to achieving the ionic strength and a mineral acid (e.g., HC1, HNO3) that primarily contributes to achieving the pH. In aspects, the treatment solution can comprise a zinc -containing compound (e.g., producing zinc ions), acopper-containing compound (e.g., producing copper ions), or combinations thereof. In aspects, the treatment solution can comprise chloride ions, nitrate ions, or combinations thereof.

[0172] In aspects, the treatment solution can optionally include a surface agent. Without wishing to be bound by theory, it is believed that the surface agent can primarily act at the interface between the glass-based substrate and the treatment solution to reduce (e.g., prevent) the dissolution of silica. For example, a surface agent can have little to no ion transport from the bulk to the interface since the surface agent may primary act at the interface. A characteristic of a surface agent is a weak (or no) concentration dependence on the effect of the surface agent over a range of at least 1 order of magnitude. An exemplary aspect of the surface agent is polyethylene glycol). As demonstrated by the examples discussed herein, polyethylene glycol) was able to produce reduced reflectance and / or reduced scatter relative to treatment solutions without poly(ethylene glycol), and the effect of poly(ethylene glycol) was largely concentration independent (over at least one order of magnitude); in contrast, the inclusion of a silica solubilizer (e.g., poly(vinyl alcohol)) does not improve the optical properties of the resulting article and the effects of the silica solubilizer is concentration dependent. In further aspects, an amount of the surface agent in the treatment solution (as a wt% of a total amount of the treatment solution) can be 10'4wt% or more, 10'3wt% or more, 10'2wt% or more, 0.1 wt% or more, 0.5 wt% or more, 1.0 wt% or more, 1.5 wt% or more, 3.0 wt% (e.g., 3 wt%) or less, 2.5 wt% or less, 2.0 wt% (e.g., 2 wt%) or less, 1.5 wt% or less, 1.0 wt% or less, 0.5 wt% or less, 0. 1 wt% or less, or 10'2wt% or less. In further aspects, an amount of the surface agent in the treatment solution (as a wt% of a total amount of the treatment solution) can be from 10'4wt% to 3 wt%, from 10'4wt% to 2.5 wt%, from 10'3wt% to 2.0 wt%, from 10'3wt% to 1.5 wt%, from 10'2wt% to 1.0 wt%, from 0.1 wt% to 0.5 wt%, or any range or subrange therebetween.

[0173] The contacting at least the intermediate first major surface 513 with a treatment solution 603 can form the depletion layer and / or the glass-based article having one or more of the properties discussed above. For example, the depletion depth (e.g., first depth) and / or depth variation can be within one or more of the corresponding ranges discussed above. In aspects, the total transmittance average over optical wavelengths from 400 nm to 800 nm or from 800 nm to 2000 nm can be within one or more of the ranges discussed above for the average transmittance (e.g.,from 94% to 100%). In aspects, the total reflectance averaged over optical wavelengths from 400 nm to 800 nm or from 800 nm to 2000 nm can be within one or more of the ranges discussed above for the average reflectance (e.g., from 0.1% to 2.0%). In aspects, the total scattering averaged over optical wavelengths from 400 nm to 800 nm or from 800 nm to 2000 nm can be within one or more of the ranges discussed above for the average scattering (e.g., from 0.1% to 5.0% or from 0.1% to 2.0%). In aspects, methods can optionally include assembling the glass-based substrate 101 into a consumer electronic device. After the contacting and / or after the assembling, methods can be complete.

[0174] In aspects, methods can further comprise rinsing the glass-based substrate with the depletion layer(s). For example, the rinsing can remove residual from the treatment solution. In further aspects, the rinsing can comprise contacting the glass-based substrate with water (e.g., purified, filtered, deionized, and / or distilled), an alkaline detergent (e.g., alkaline detergent solution), or combinations thereof.

[0175] In aspects, methods in accordance with aspects of the disclosure may consist of the steps discussed above. For example, the glass-based substrate may not be further treated between one or more (or even all of) the steps described above. Throughout the disclosure, the phrase “not further treated” or “not be further treated” excludes treatments to the first major surface other than the stated contacting with a solution and rinsing with water (e.g., purified, filtered, deionized, distilled). Exemplary aspects of treatments that can be excluded under “not further treated” or “not be further treated” include treatment with additional etchants (e.g., acidic solutions, fluorine-containing solutions), treatment solutions (e.g., alkaline solutions, detergents), and mechanical polishing of the glass-based substrate. Also, as discussed above, in aspects, methods can comprise only contacting the glass-based substrate with the treatment solution although the additional steps discussed above can be present in other aspects.

[0176] Additionally, the glass-based substrate having the depletion layer can further be characterized using higher resolution SEM images (e.g., at 100,000 times resolution). As used herein, pore size is determined from SEM images at 100,000 times magnification of the glass-based sample (without any etching). In aspects, the glass-based based sample can be free of pores visible at this resolution. In aspects, any pores visible may have a maximum size (i.e., maximum cross-sectional dimension) less than 10 nm, less than or equal to 8 nm, less than or equal to 5 nm, less than orequal to 4 nm, less than or equal to 3 nm, less than or equal to 2 nm, or less than or equal to 1 nm. In aspects, a median pore size can be within one or more of the ranges discussed above in this paragraph. Additionally, high-resolution porosity is determined using SEM images at 100,000 times magnification, where the high- resolution porosity can be within one or more of the ranges discussed above for the porosity (e.g., less than or equal to 1.0%, from greater than or equal to 0.0% to less than or equal to 0.2%, from greater than or equal to 0.0% to less than or equal to 0.1%).

[0177] In aspects, the glass-based substrate can be free of phase separation. As used herein, phase separation in a glass-based sample is determined from SEM images at 100,000 times magnification of the glass-based sample after it is treated with a 0.1 wt% ammonium bifluoride (NH4HF) solution maintained at 45°C for 10 minutes. Without wishing to be bound by theory, it is believed that the phases is many phase separated glasses have different etching rates (e.g., acid resistance) such that the etching treatment described above can preferentially etch one of the phases while leaving the other phase(s) largely unaffected such that the phase(s) with higher acid resistance can be visualized. In contrast, a glass-based material free of phase separation would be expected to uniformly etch.

[0178] Additionally, in aspects, a porosity measured for a cross-sectional view (e.g., see FIG. 7 - perpendicular to the first major surface) of the depletion layer can be within one or more of the ranges discussed above in this paragraph (e.g., from 0.0% to 1.0%, from 0.0% to 0.1%, or no detectable porosity). In contrast, without wishing to be bound by theory, it is believed that any structure formed by acid leaching of phase separated glasses would produce significant porosity. For example, Figures 3-7 in Elmer et al., “Phase Separation in Borosilicate Glasses as Seen by Electron Microscopy and Scanning Electron Microscopy”, Journal of the American Chemical Society, 53.4 (1970): 171-175 show microstructures with a significant phase separation. If these microstructures were acid leached, the alkali-borate-rich phase would be expected to be removed entirely, leaving large pores and an associated high level of porosity on the order of 10% or more.

[0179] Additionally, in aspects, the depletion layer can be depleted in boron (e.g., B2O3) relative to the bulk (e.g., when there is a non-zero amount of B2O3 in the bulk). In further aspects, a difference between the concentration of boron in the bulk minus a concentration of boron at a location within the depletion layer (e.g., 200 nm,500 nm, or 700 nm from the first major surface or an average concentration) can be 5 mol% or more, 6 mol% or more, 7 mol% or more, 8 mol% or more, 9 mol% or more, 10 mol% or more, 11 mol% or more, 12 mol% or more, 13 mol% or more, 14 mol% or more, 15 mol% or more, 20 mol% or less, 18 mol% or less, 15 mol% or less, 14 mol% or less, 13 mol% or less, 12 mol% or less, 11 mol% or less, 10 mol% or less, 9 mol% or less, 8 mol% or less, or 7 mol% or less. In further aspects, a difference between the concentration of boron in the bulk minus a concentration of boron at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be in a range from greater than or equal to 5 mol% to less than or equal to 20 mol%, from greater than or equal to 6 mol% to less than or equal to 18 mol%, from greater than or equal to 7 mol% to less than or equal to 15 mol%, from greater than or equal to 8 mol% to less than or equal to 14 mol%, from greater than or equal to 9 mol% to less than or equal to 13 mol%, or any range or subrange therebetween. In further aspects, a concentration of boron at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration), as a percentage of a concentration of boron in the bulk, can be 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 7% or less, 5% or less, 3% or less, 1% or less, 0.01% or more, 0.1% or more, 1% or more, 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, or 40% or more. In further aspects, a concentration of boron at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration), as a percentage of a concentration of boron in the bulk, can be in a range from greater than or equal to 0.01% to less than or equal to 50%, from greater than or equal to 0.01% to less than or equal to 30%, from greater than or equal to 0.1% to less than or equal to 25%, from greater than or equal to 0. 1% to less than or equal to 20%, from greater than or equal to 1% to less than or equal to 15%, from greater than or equal to 1% to less than or equal to 10%, from greater than or equal to 2% to less than or equal 7%, from greater than or equal to 3% to less than or equal to 5%, or any range or subrange therebetween. In even further aspects, a concentration of boron at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration), as a percentage of a concentration of boron in the bulk, can be from greater than or equal to 0.01% to less than or equal to 50%, from greater than or equal to 0. 1% to less than or equal to 25%, from greater than or equal to 1% to lessthan or equal to 10%, or any range or subrange therebetween. In further aspects, a concentration of boron at a location within the depletion layer (e.g., 200 nm, 500 nm, or 700 nm from the first major surface or an average concentration) can be less than or equal to 1.0 mol%, less than or equal to 0.5 mol%, less than or equal to 0.2 mol%, less than or equal to 0.1 mol% (e.g., 0.10 mol%), less than or equal to 0.05 mol%, less than or equal to 0.02 mol%, or less than or equal to 0.01 mol%.

[0180] Additionally, in aspects, the treatment solution can comprise one or more of copper ions (e.g., Cu2+ions), zinc ions (e.g., Zn2+ions), manganese ions (e.g., Mn2+), chloride ions (O’), nitrate ions (NO.f). and / or sulfate ions (SO42'). In further aspects, the treatment solution can comprise manganese ions (e.g., Mn2+). For example, the treatment solution can be formed by dissolving a manganese salt therein, where the manganese salt can be manganese chloride, manganese nitrate, manganese sulfate, or combinations thereof. Alternatively or additionally, as discussed above, the treatment solution can be formed by dissolving a copper salt therein, where the copper salt can be copper chloride (e.g., CuCh), copper nitrate (e.g., Cu(NOs)2), copper sulfate (CuSO-i). or combinations thereof. Alternatively or additionally, as discussed above, the treatment solution can be formed by dissolving a zinc salt therein, where the zinc salt can be zinc chloride, zinc nitrate, zinc sulfate, or combinations thereof. It is to be understood that the treatment solution can be formed by dissolving more than one of a copper salt, a zinc salt, and / or a manganese salt with an optional acid in addition to obtain a predetermined pH and a predetermined ionic strength, although the predetermined pH and predetermined ionic strength can be achieved using a single salt in other aspects.EXAMPLES

[0181] Various aspects will be further clarified by the following examples. The results discussed with reference to FIGS. 9-10 and 12-16 are based on simulations whereas the results in FIGS. 7-8 and 17-45 are experimental results. For the experimental results, the composition of glasses having Compositions A-E are reported in Table 1. Compositions A-B and D-E have from 10 mol% to 20 mol% R2O while Composition C is free of R2O (alkali metal oxides). Consequently, Compositions A-B and D-E are per-alkaline while Composition C is per-aluminous. Compositions A and C-D have non-zero RO (e.g., from 1 mol% to 12 mol%) while Compositions B and E are free of RO (alkaline earth oxides).Table 1: Properties of Examples 1-6

[0182] The simulation results presented in FIGS. 9-10 used a simplified model of the depletion layer as having a single linear refractive index profile (e.g., corresponding to just region 1123 of the refractive index profile 1116 in the depletion layer shown at the bottom of FIG. 11). FIGS. 9-10 schematically illustrate reflectance curves having reflectance (R) in % on the vertical axis 903 (e.g., y-axis) as a function of optical wavelength (X) in nanometers on the horizontal axis 901 (e.g., x- axis) simulated for glass-based articles having a depletion layer. In FIG. 9, the refractive index difference across the depletion layer is modeled as 0.05 with various depletion depths (e.g., first depths) of 0.25 pm (curve 911), 0.50 pm (curve 913), and 1.0 pm (curve 915). Dashed line 905 corresponds to a reflectivity of 0.5%. As shown in FIG. 9, the reflectance remains at or below the dashed line 905 for a wider range of optical wavelengths as the depletion depth increases (going from curve 911 to curve 915). For example, curve 911 has reflectance above 2% beyond 1100 nm while curves 913 and 915 remain below 1% for all optical wavelengths shown. Consequently, achieving broadband antireflective properties are associated with a sufficiently thick depletion layer (e.g., greater than 0.25 pm, from 300 nm to 10.0 pm). In FIG. 10, the depletion depth is modeled as 1.0 pm and various differences in refractive index: 0.05 (curve 915), 0.10 (curve 917), and 0.20 (curve 919). As shown, the reflectanceincreases with increasing refractive index distance (going from curve 915 to curve 919), which is largely attributed to Fresnel reflectance.

[0183] FIG. 11 will be used to describe the more complicated model used to obtain the results presented in FIGS. 12-16. FIG. 11 compares the experimental TEM image from FIG. 7 with the three-part refractive index model for the depletion layer shown below, where the refractive index is shown on the vertical axis 1103 (e.g., y- axis) as a function of distance (d) from the first major surface in micrometers (pm) on the horizontal axis 1101 (e.g., x-axis). As shown, there is an increase from the refractive index of air 1105 (about 1) at location 1112 corresponding to the first major surface 705 of the glass-based substrate. In the first region 1121 of the refractive index profile (between location 1112 and 1114), the refractive index increases with the lower refractive index near the surface attributable to surface irregularities and / or uneven etching of the first major surface (e.g., by the treatment solution), which is consistent with the change in optical density of the TEM image near the first major surface 705. In the second region 1123, between location 1114 and location 1118, the refractive index profile 1115 more gradually increases, which may be the effects of the concentration profile for depleted ions (e.g., alkali metal oxides, alkaline earth metal oxides, alumina). This second region was the only part modeled in the simplified model discussed above. In the third region 1125, between location 1118 and location 1116, the refractive index increases towards the bulk refractive index 1111 (e.g., of the bulk 703). As shown, location 1118 can correspond to the minimum depth 718 of the depletion layer 715 and location 1116 can correspond to the maximum depth 716 of the depletion layer 715; consequently, the depth variation 719 in the depth of the depletion layer 715 averages out to produce the refractive index gradient in this third region. Also, it can be seen the depletion depth 709 is in between points 716 or 718 (corresponding to locations 1118 and 1116) since the depletion depth 709 is the average of the interface 711 (see FIG. 7) rather than the maximum depth 716 of the depletion layer 715. In the model, the depth and refractive index for each of the points discussed in the paragraph (e.g., points 1112, 12114, 1118, and 1116) can be modified, and the effects will be discussed below with reference to FIGS. 12-16

[0184] In FIGS. 12-14, the vertical axis corresponds to reflectance (R) in % on the vertical axis 1203 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 1201 (i.e., x-axis). In FIG. 12, curves 1205(1.0 pm), 1207 (1.5 pm), 1209 (2.0 pm), 1211 (2.5 pm), 1213 (3.0 pm), and 1215 (3.5 pn) correspond to different depths for the depletion layer (see distance between points 1112 and 1116 in FIG. 11). As shown, curve 1205 (1.0 pm) having the smallest thickness has a reflectance value greater than 1% beyond 1000 nm (e.g., greater than 2% around 1100 nm to 1200 nm); curve 1207 (1.5 pm) has a reflectance value greater than 1% around 1500 nm (e.g., greater than 2% around 1550 nm to 1800 nm); and curve 1209 (2.0 pm) has a reflectance value greater than 1% around 1950 nm (or 2000 nm). Interestingly, the point where these curves (e.g., curves 1205, 1207, and 1209) first go higher than 1% (or 2%) - starting from 350 nm or 400 nm) appears to roughly correspond to the depletion depth. Based on this observation, it is expected that broadband anti-reflective properties will extend to at least an optical wavelength corresponding to the depletion depth. Consequently, anti-reflective properties over the visual spectrum is expected when the depletion depth is at least 800 nm. Likewise, anti-reflective properties are expected to extend to about 2000 nm when the depletion depth is at least 2.0 pm. Further, curves 1211, 1213, and 1215 having depletion depths greater than 2.0 pm have reflectance values less than 1% over the entire range of optical wavelengths shown in FIG. 12.

[0185] In FIG. 13, curves 1311 (100 nm), 1313 (200 nm), 1315 (400 nm), and 1317 (600 nm) correspond to different values for the depth variation 719 (see points 716 and 718 as well as locations 1118 and 1116 in FIG. 11). As shown, the maximum reflectance values (e.g., over optical wavelengths or from about 350 nm to 2000 nm) decrease as the depth variation increases (e.g., from 100 nm in curve 1311 to 200 nm in curve 1313). When the depletion depth is 200 nm or more (curves 1313, 1315, and / or 1317) is less than 1.5% (about 1% or less) over visual wavelengths (or optical wavelengths from 350 nm to about 1450 nm). Increasing the depletion depth to 600 nm (curve 1317) has reflectance values below 1.5% over the entire range of optical wavelengths shown (and below 1% for optical wavelengths from 350 nm to 1800 nm).

[0186] In FIG. 14, curves 1411, 1413, and 1415 correspond to different values for the depth of the first region in the model (see region 1121 between locations 1112 and 1114 in FIG. 11). As shown, the reflectance values in the infrared red region is the highest for curve 1411 (200 nm - the smallest depth of the first region). When this depth is increased from 200 nm to 400 nm, the reflectance value isbelow 1% over visual wavelengths (and for optical wavelengths from 350 nm to about 1800 nm or more).

[0187] In FIGS. 15-16, reflectance (R) in % is presented on the vertical axis 1503 or 1603 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 1501 or 1601 (i.e., x-axis). In FIG. 15, curves 1505 (1.00), 1507 (1.05), 1509 (1.10), 1511 (1.15), 1513 (1.20), and 1515 (1.25) correspond to different values of the refractive index at the first major surface (surface refractive index - see location 1112 in FIG. 11). As shown, the reflectance increases as the surface refractive index increases. Without wishing to be bound by theory, it is believed that this trend can largely be attributed to Fresnel reflection at the interface between air and the depletion layer. Still, these curves indicate that an average reflectance of about 1% or less can be obtained (e.g., over visual optical wavelengths) for a surface refractive index of less than 1.20 (e.g., from 1.00 to 1.15), as shown in curves 1505, 1507, 1509, and 1511. As discussed above, it is believed that the surface refractive index can be decreased through increased leaching (e.g., depletion) and / or non-uniform etching at and / or near the first major surface.

[0188] In FIG. 16, curves 1605, 1607, 1609, 1611, and 1613 correspond to different trends for the refractive index profile in the second region (see refractive index profile 1115 in FIG. 11). Curve 1609 corresponds to a substantially flat refractive index profile (in the second region) while curve 1607 is slightly negative (going from position 1114 to position 1118 in FIG. 11) and curve 1605 is more negative (than curve 1607). Going the other direction, the refractive index profile (in the second region) for curve 1611 is slightly positive (corresponding to the actual refractive index profile 1115 shown in region 1123 in FIG. 11) and curve 1613 is even more positive than curve 1611. Curve 1605 has regions with greater than 1% reflectance throughout the visual wavelengths. Curves 1607 has a few locations with reflectance of about 1% (or more) toward higher visual wavelengths. However, curves 1609, 1611, and 1613 (and most of curve 1607) have reflectance values of about 1% or less over the optical wavelengths shown in FIG. 16. This indicates that the reflectance over visual wavelengths is largely insensitive to the gradient of the refractive index profile (although a neutral or positive gradient may be preferred in some aspects. Although not shown, it is expected that a discontinuous refractive index profile having regions with abrupt (e.g., sharp, steep) changes in refractive index could lead to increased reflectance (and / or scattering), for example, due to Fresnelreflection. Consequently, a continuous refractive index profile may enable low reflectance (and / or scattering).

[0189] FIGS. 17-20 present experimental results for glass-based substrates having Composition C. FIGS. 17-18 present properties (e.g., reflectance, scattering) as a function of pH of the treatment solution of ZnCh maintained at 120°C for 3 days, where the pH was controlled by adjusting and amount of HC1 added while maintaining a constant ionic strength. In FIG. 17, reflectance (R) in % is presented on the vertical axis 1703 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 1701 (i.e., x-axis). Regarding the pH of the treatment solution, curve 1705 corresponds to a pH of 0.3, curve 1707 corresponds to a pH of 0.7, curve 1709 corresponds to a pH of 0.9, curve 1711 corresponds to a pH of 1.0, curve 1713 corresponds to a pH of 1.2, curve 1715 corresponds to a pH of 1.5, curve 1717 corresponds to a pH of 1.9, and curve 1719 corresponds to a pH of 2.2. All of these curves have an average reflectance over visual wavelengths (e.g., from 400 nm to 800 nm) of less than 2% (e.g., less than 1.5%, and / or 1.0% or less). Consequently, treatment solutions within the range of pHs presented here (e.g., 0.3 to 2.2) can produce antireflective articles for visual wavelengths. Further, curves 1707, 1709, 1711, and 1713 have an average reflectance over infrared optical wavelengths from 800 nm to 2000 nm less than 2% (e.g., less than 1.5%, and / or 1.0% or less) in addition to having similarly low average reflectance over visual wavelengths (e.g., from 400 nm to 800 nm). Consequently, treatment solutions with a pH between 0.3 and 1.5 (e.g., from 0.7 to 1.2 - corresponding to curves 1707, 1709, 1711, and 1713) can provide broadband antireflective articles having antireflective properties over both visual wavelengths and infrared wavelengths (e.g., from 400 nm to 2000 nm).

[0190] In FIG. 18, scattering (S) in % is presented on the vertical axis 1803 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 1801 (i.e., x-axis). As shown, curve 1805 corresponds to a pH of 0.3, curve 1807 corresponds to a pH of 0.7, curve 1809 corresponds to a pH of 0.9, curve 1811 corresponds to a pH of 1.0, curve 1813 corresponds to a pH of 1.2, curve 1815 corresponds to a pH of 1.5, curve 1817 corresponds to a pH of 1.9, and curve 1819 corresponds to a pH of 2.2. Generally, these curves show high scattering at low visual wavelengths (and ultraviolent wavelengths) (e.g., less than 600 nm, less than 500 nm, less than 400 nm). However, the scattering decreases to about 1% or less as the optical wavelength increases (e.g., from 800 nm to 2000). Indeed, all of the curvesshown in FIG. 18 have an average scatering over optical wavelengths from 800 nm to 2000 nm of 1.0% or less. Additionally, all of the curves shown in FIG. 18 have an average scatering over optical wavelengths from 400 nm to 800 nm of less than 5.0%. Further, curves 1817 and 1819 have an average scatering over optical wavelengths from 400 nm to 800 nm of less than 1.0%.

[0191] FIGS. 19-20 present properties (e.g., reflectance, transmittance) for glass-based substrates treated with different anions in the treatment solutions - chloride (i.e., CuCh), nitrate (i.e., CufNCh ) or both - having an ionic strength of 14.1 maintained at 120°C for 3 days. In FIG. 19, reflectance (R) in % is presented on the vertical axis 1903 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 1901 (i.e., x-axis). For curve 1905, the treatment solution comprised nitrate ions, namely Cu(NOs)2; for curve 1907, the treatment solution comprised chloride ions, namely CuCh; and for curve 1909, the treatment solution comprised both nitrate ions and chloride ions (i.e., a mix of CU(NOS)2 and CuCh). Curve 1907 (nitrates) has a higher reflectance than curve 1909 (chloride). The combination of anions (chlorides and nitrates) in curve 19505 has lower reflectance than either anion alone. Curves 1905, 1907, and 1909 have average reflectance over optical wavelengths from 400 nm to 800 and over optical wavelengths from 800 nm to 2000 nm of 5% or less.

[0192] In FIG. 20, transmitance (T) in % is presented on the vertical axis 2003 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 2001 (i.e., x-axis). For curve 2005, the treatment solution comprised nitrate ions, namely Cu(NOs)2; for curve 2007, the treatment solution comprised chloride ions, namely CuCh; and for curve 2009, the treatment solution comprised both nitrate ions and chloride ions (i.e., a mix of Cu(N 0. )2 and CuCh). Curve 2005 (chlorides) has higher transmitance (above about 550 nm) than curve 2007 (nitrates). Curve 2009 (both nitrates and chlorides) has transmitance largely between 97% and about 98% (between about 450 nm and 2000 nm). Curves 2005, 2007, and 2009 have average transmitance over optical wavelengths from 400 nm to 800 of 97% or more and over optical wavelengths from 800 nm to 2000 nm of 95% or more. Taken together, the results in FIGS. 19-20 demonstrate that including nitrate ions has improved reflectance and transmitance properties than the treatment solutions without nitrate ions (for the copper solutions with an ionic strength of 14.1).

[0193] FIGS. 21-33 present experimental results for glass-based substrates having Composition B. FIGS. 21-23 present properties (e.g., reflectance, transmittance, scattering, respectively) of glass-based substrates treated with treatment solutions having an ionic strength of 17.6 including copper chloride (CuCh) with different amounts of HC1 maintained at 120°C for 1 day. The amount of added HC1 is 0 wt% for curves 2105, 2205, and 2305, 0.2 wt% for curves 2107, 2207, and 2307, 1.0 wt% for curves 2109, 2209, and 2309, and 2.0 wt% for curves 2111, 2211, and 2311. In FIG. 21, reflectance (R) in % is presented on the vertical axis 2103 (i.e., y- axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 2101 (i.e., x-axis). As shown in FIG. 21, the lowest reflectance over the visual wavelengths (e.g., from 400 nm to 800 nm) is shown in curve 2105 (no added HC1) with the corresponding reflectance increasing as more HC1 is added. Consequently, for Composition B (treated with a treatment solution having an ionic strength of 17.6 from copper chloride), decreasing the pH (increasing the amount of added HC1) is associated with increased reflectance. Similar trends are also observed over reflectance averaged over infrared wavelengths (e.g., from 800 nm to 2000 nm). Without wishing to be bound by theory, it is believed that decreasing pH (increasing the amount of added HC1) is associated with a faster etching rate of the treatment solution. Consequently, decreasing pH (increasing the amount of added HC1) beyond a predetermined point is believed to decrease a region having a surface refractive index gradient (e.g., see region 1121 in FIG. 11) by etching away at least a portion of this region.

[0194] In FIG. 22, transmittance (T) in % is presented on the vertical axis 2203 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 2201 (i.e., x-axis). As shown in FIG. 22, the highest transmittance over the visual wavelengths (e.g., from 400 nm to 800 nm) is shown in curve 2205 (no added HC1) with the corresponding transmittance decreasing as more HC1 is added. Similar trends are also generally observed over transmittance averaged over infrared wavelengths (e.g., from 800 nm to 2000 nm). This is consistent with the understanding and trends discussed above with reference to FIG. 21.

[0195] In FIG. 23, scattering (T) in % is presented on the vertical axis 2303 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 2301 (i.e., x-axis). All of the curves shown in FIG. 23 have low scattering (e.g., 1% or less, average scattering of about 0.5% or less), for example,averaged over optical wavelengths from 400 nm to 800 nm and / or from 800 nm to 2000 nm). While there are slight differences between these curves for the visual wavelengths, the average scattering for optical wavelengths from 400 nm to 800 nm is still 0.5% or less for all these curves. The scattering appears to be slightly higher for curve 2305 than the other curves shown in FIG. 23 for optical wavelengths above 1400 nm. Taken together FIGS. 21-23, indicate that the change in reflectance is primarily balanced with an opposite change in transmittance (rather than scattering), suggesting that it is the decrease in the region with the surface refractive index gradient and an increase in Fresnel reflection.

[0196] FIGS. 24-25 present properties (e.g., reflectance, transmittance, respectively) of glass-based substrates treated with treatment solutions containing sodium chloride, hydrochloric acid, copper chloride, or combinations thereof maintained at 120°C for 3 days. For curves 2405 and 2505, the glass-based substrate was not treated with a treatment solution; for curves 2407 and 2507, the treatment solution contained sodium chloride (NaCl) (only) having 7.33 ionic strength; for curves 2409 and 2509, the treatment solution contained hydrochloric acid (HC1) (only) having 0.35 ionic strength; for curves 2411 and 2511, the treatment solution contained copper chloride (CuCh) having an ionic strength of 14.2; and for curves 2413 and 2513, the treatment solution contained both hydrochloric acid (HC1) and sodium chloride (NaCl) with a total ionic strength of 7.97. FIG. 24 presents reflectance (R) in % on the vertical axis 2403 (e.g., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 2401 (i.e., x-axis). Consequently, curves 2407 and 2507 contain the ionic strength with a substantially neutral pH whereas curves 2409 and 2509 contain a low pH with the ionic strength. Curves 2411, 2413, 2511, and 2513 contain a mixture of decreased pH and increased ionic strength. FIG. 24 shows the sodium chloride (only) treatment solution (curve 2407) does not decrease reflectance relative to curve 2405 (no treatment solution). This indicates that the ionic strength of the treatment solution alone is not sufficient to produce antireflective articles. The other curves (curves 2409, 2411, and 2413) have an acidic pH and lower reflectance than curve 2405, which further indicates that pH is an important component of the treatment solution.

[0197] FIG. 25 presents reflectance (R) in % on the vertical axis 2503 (e.g., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 2501 (i.e., x-axis). As in FIG. 24, FIG. 25 shows that the sodium chloride (NaCl)(only) treatment solution (curve 2507) does not substantially change the optical properties (e.g., transmittance) of the untreated article (curve 2505). Curves 2511 and 2513 with both high ionic strength and acidic pH achieve increased transmittance over the entire range of optical wavelengths shown (e.g., from 400 nm to 800 nm and from 800 nm to 2000 nm). In contrast, curve 2509 indicates that the HC1 (only) solution has decreased transmittance at least over visual wavelengths (e.g., from 400 nm to 800 nm) relative to the untreated article (curve 2505). This demonstrates that pH alone is not sufficient to obtain an antireflective article with high transmittance. Consequently, it is a combination of the ionic strength and acidic pH that achieve the optical properties of the glass-based substrate having the depletion layer of the present disclosure.

[0198] FIG. 26 presents reflectance for treatment solutions having different ionic strength achieved through copper chloride and 100 ppm added silica maintained at 120°C for 3 days (for Composition B). In FIG. 26, reflectance (R) in % is presented on the vertical axis 2603 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 2601 (i.e., x-axis). Curve 2605 corresponds to an ionic strength of 6, curve 2607 corresponds to an ionic strength of 10, curve 2609 corresponds to an ionic strength of 14, curve 2611 corresponds to an ionic strength of 18, and curve 2613 corresponds to an ionic strength of 20.4. As shown in FIG. 26, the average reflectance decreases as the ionic strength decreases (going from curve 2613 to curve 2605). Notably, curves 2605, 2607, and 2609 have average reflectance averaged over optical wavelengths from 400 nm to 800 nm of 1.0% or less. This demonstrates that for Composition B, ionic strengths as low as 6 can produce an antireflective article. Without wishing to be bound by theory, it is believed that the ionic strength that will achieve a minimum reflectance will change based on a degree of acid resistance of the particular glass composition.

[0199] FIGS. 27-28 present properties (e.g., reflectance, transmittance, respectively) of glass-based substrates treated with treatment solutions having a consistent ionic strength of 17.6 with various concentrations of added silica maintained at 120°C. The treatment solution correspond to curves 2705 and 2805 had no added silica (0 ppm), curves 2707 and 2807 had 10 ppm added silica, and curves 2709 and 2809 had 100 ppm added silica in the treatment solution. In FIG. 27, reflectance (R) in % is presented on the vertical axis 2703 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 2701 (i.e., x-axis). Curve 2707 has similar average reflectance over optical wavelengths from 400 nm to 800 run to curve 2705 and curve 2707 notably increased reflectance from 900 nm to about 1400 nm (relative to curve 2705). The average reflectance of curve 2709 is higher than that of curve 2705 or 2707 for optical wavelength from 400 nm to 800 and from at least 800 nm to 1400 nm. Overall, FIG. 27 indicates that adding silica does not improve (i.e., decrease reflectance). In FIG. 28, transmittance (T) in % is presented on the vertical axis 2803 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 2801 (i.e., x-axis). As shown, the curve 2805 (no added silica) had the same or higher transmittance than the other curves 2807 and / or 2809 with added silica. Taken together, FIGS. 27-28 indicate that added silica does not improve the resulting optical properties. Consequently, FIGS. 29-33 explore the effects of additives (e.g., polymeric additives) that may modify an amount of silica in the solution.

[0200] FIGS. 29-30 present properties (e.g., reflectance, transmittance, respectively) of glass-based substrates treated with treatment solutions having a consistent ionic strength of 17.6 obtained by copper chloride (CuCh) with various concentrations of added poly(vinyl alcohol) (PVA) maintained at 120°C for 3 days (for Composition B). The treatment solutions correspond to curves 2905 and 3005 had no added PVA, curves 2907 and 3007 had 0.03 wt% of added PVA having a number-average molecular weight Mn of about 9,000 Daltons, and curves 2909 and 3009 had 0.3 wt% of added PVA having a number-average molecular weight Mn of about 90,000 Daltons. In FIG. 29, reflectance (R) in % is presented on the vertical axis 2903 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 2901 (i.e., x-axis). In FIG. 29, curves 2907 and 2909 have much lower transmittance than curve 2905, especially over optical wavelengths from 400 nm to 800 nm and from 800 nm to at least 1400 nm. In FIG. 30, transmittance (T) in % is presented on the vertical axis 3003 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 3001 (i.e., x-axis). Interestingly, curves 3007 and 3009 have reduced reflectances than curve 3005. However, due to much lower transmittance (see FIG. 29) for the treatment solutions with PVA additives, PVA additives do not improve the optical properties of the resulting glass-based article. Also, due to the difference in optical properties between glass-based substrates treated with the 0.03 wt% and 0.3 wt% PVA additive, it appears that the effect of PVA is concentration-dependent.

[0201] FIGS. 31-33 present properties (e.g., reflectance, transmittance, and scattering, respectively) of glass-based substrates treated with treatment solutions having a consistent ionic strength of 14.1 obtained by copper chloride (CuCh) with various concentrations of added poly(ethylene glycol) (PEG) with a number-average molecular weight Mn of about 2,000 Daltons maintained at 120°C for 3 days. The treatment solutions correspond to curves 3105, 3205, and 3305 with no added PEG, curves 3107, 3207, and 3307 with 0.05 wt% added PEG, curves 3109, 3209, and 3309 with 0.10 wt% added PEG, curves 3111, 3211, and 3311 with 0.5 wt% added PEG, and curves 3113, 3213, and 3313 with 1 wt% added PEG. In FIG. 31, reflectance (R) in % is presented on the vertical axis 3103 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 3101 (i.e., x- axis). As shown in FIG. 31, the reflectance from the treatment solutions with any amount of PEG (curves 3107, 3109, 3111, and 3113) was lower over infrared wavelengths (e.g., from about 800 nm to 2000 nm) and the same or lower reflectance over visual wavelengths (e.g., from 400 nm to 800 nm) relative to the reflectance from the treatment solution without PEG (curve 3105). While the reflectance is slightly lower for higher amounts of PEG, the reflectance curves for essentially any amount of PEG (especially curves 3109, 3111, and 3113) are virtually the same, suggesting that the effect of PEG may be largely concentration dependence. As discussed above, this suggests that (unlike PVA) PEG may act as a surface agent.

[0202] In FIG. 32, transmittance (T) in % is presented on the vertical axis 3203 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 3201 (i.e., x-axis). As shown, transmittance curves corresponding to treatment solutions with any amount of PEG are 97% or more over the entire wavelength range shown. These curves 3207, 3209, 3211, and 3213 (PEG) have about the same or higher transmittance than curve 3205 (no PEG) over the entire wavelength range shown (and averaged over optical wavelengths from 400 nm to 800 nm and / or from 800 nm to 2000 nm). As with the trend seen in FIG. 31, FIG. 32 shows that the transmittance for curves 3209, 3211, and 3213 is essentially the same.

[0203] In FIG. 33, scattering (S) in % is presented on the vertical axis 3303 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 3301 (i.e., x-axis). The scattering of curves 3309, 3311, and 3313 is less than 1% over the entire wavelength range shown (and averaged over optical wavelengths from 400 nm to 800 nm and / or from 800 nm to 2000 nm). Specifically,curves 3309, 3311, and 3313 have notably lower scattering than curve 3305 (no PEG) over visual wavelengths (e.g., from 400 nm to 800 nm) and from 800 nm to at least 1200 nm. The scattering was higher for curve 3305 (having the lowest non-zero amount of PEG) than curves 3309, 3311, and 3313, but curve 3305 still had lower scattering at shorter optical wavelengths (e.g., from 400 nm to 600 nm) than curve 3305. Overall, FIGS. 31-33 demonstrate that adding PEG to the treatment solution improves optical properties (e.g., increased transmittance, decreased reflectance, decreased scattering). Also, the evidence indicates that PEG is acting as a surface agent. The applicability of adding PEG to the treatment solution to improve optical properties was further investigated for a different composition (Composition C instead of Composition B) in FIGS. 34-36.

[0204] FIGS. 34-36 present experimental results of properties (e.g., transmittance, reflectance, scattering, respectively) for glass-based substrates having Composition C that were treated with treatment solutions having an ionic strength of 14.4 including copper chloride (CuCh) and various amounts of added PEG (Mn of about 2000 Daltons) maintained at 120°C for 3 days. The amount of added PEG in the treatment solution was none in curves 3405, 3505, and 3605, 0.5 milliMolar (mM) (e.g., 0.05 wt%) in curves 3407, 3507, and 3607, 5 mM (e.g., 0.5 wt%) in curves 3409, 3509, and 3609, and 20 mM (e.g., 2.5 wt%) in curves 3411, 3511, and 3611. In FIG. 34, transmittance (T) in % is presented on the vertical axis 3403 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 3401 (i.e., x-axis). As in FIG. 32, in FIG. 34, the curves corresponding to added PEG (curves 3407, 3409, 3411) had higher transmittance than curve 3405 (no PEG). The average transmittance over optical wavelengths from 400 nm to 800 nm (and from 800 nm to 2000 nm) was 98% or more for curves 3407, 3409, and 3411. The transmittance in curves 3409 and 3411 are essentially the same.

[0205] In FIG. 35, reflectance (R) in % is presented on the vertical axis 3503 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 3501 (i.e., x-axis). As shown in FIG. 35, the reflectance from the treatment solutions with any amount of PEG (curves 3507, 3509, and 3511) was lower over infrared wavelengths (e.g., from about 800 nm to 2000 nm) relative to the reflectance from the treatment solution without PEG (curve 3505). Also, the reflectance decreases as the amount of PEG increases. In FIG. 36, scattering (S) in % is presented on the vertical axis 3603 (i.e., y-axis) as a function of optical wavelength(X) in nanometers (nm) on the horizontal axis 3601 (i.e., x-axis). Curves 3607, 3609, and 3611 (non-zero PEG) are lower than curve 3605 (no PEG) for all optical wavelengths shown in FIG. 36. Also, curves 3607, 3609, and 3611 have an average scattering of less than 1% for all plotted points as well as averaged over optical wavelengths from 400 nm to 800 (and / or from 800 nm to 2000 nm). Taken together, FIGS. 34-36 indicate that the PEG decreases scattering (more strongly at lower optical wavelengths) and decreases reflectance (more strongly at higher optical wavelengths) that corresponds to higher transmittance (relative to treatment solutions with no PEG). Based on the similar improvement in optical properties for glass-based substrates with Composition B (FIGS. 31-33) and Composition C (FIGS. 34-36), it is expected that this behavior is generally applicable to aspects of treatment solutions.

[0206] FIGS. 37-38 present experimental results of properties (e.g., reflectance, scattering) for glass-based substrates having Composition C that were treated with treatment solutions having an ionic strength of 14.4 including copper chloride (CuCh) and a pH of 1.0 obtained by adding HC1 either with or without the addition of PEG maintained at 120°C for 1 day. Compared to the treatment solutions in FIGS. 34-36, the treatment solutions in FIGS. 37-38 have the addition of HC1 to further control the pH. Curves 3705 and 3805 correspond to the treatment solution without PEG while curves 3707 and 3807 correspond to the treatment solution with 5 mM (e.g., 0.5 wt%) PEG. In FIG. 37, reflectance (R) in % is presented on the vertical axis 3703 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 3701 (i.e., x-axis). As shown, curve 3707 has lower reflectance in the infrared wavelengths than curve 3705 and a lower overall average reflectance. Also, compared to curve 3509 (see FIG. 35) having the same amount of PEG, curve 3707 has lower reflectance (especially at higher optical wavelengths). In FIG. 38, scattering (S) in % is presented on the vertical axis 3803 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 3801 (i.e., x-axis). As shown, curve 3807 has lower scattering than curve 3805 for all optical wavelengths (most notably for the visual optical wavelengths - from 400 nm to 800 nm). From 400 nm to 2000 nm, curve 3807 is below 1% scattering. Taken together, the addition of HC1 can improve reflectance in the infrared. Also, the addition of PEG can reduce scattering over a broad spectrum and reflectance in the infrared.

[0207] FIGS. 39-41 present experimental results of properties (e.g., reflectance, transmittance, scattering, respectively) for glass-based substrates havingdifferent compositions (Compositions A-E) that were treated with treatment solutions having an ionic strength of 20.4 including copper chloride (CuCh) with different amounts of HC1 maintained at 120°C for 3 days. Curves 3905 and 4005 correspond to an untreated glass-based substrate comprising Composition B; curves 3907, 4007, and 4107 correspond to a treated glass-based substrate comprising Composition A; curves 3909 and 4009 correspond to a treated glass-based substrate comprising Composition B; curves 3911, 4011, and 4111 correspond to a treated glass-based substrate comprising Composition C; curves 3913, 4013, and 4113 correspond to a treated glass-based substrate comprising Composition D; and curves 3915, 4015, and 4115 correspond to a treated glass-based substrate comprising Composition E. In FIG. 39, reflectance (R) in % is presented on the vertical axis 3903 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 3901 (i.e., x-axis). As shown, the treated substrates (curves 3907, 3909, 3911, 3913, and 3915) have lower reflectance than the untreated substrate (curve 3905) for all optical wavelengths shown. Curves 3911 and 3913 remain below 1% for optical wavelengths from 250 nm to about 1200 nm (e.g., from 400 nm to 800 nm). In FIG. 40, transmittance (T) in % is presented on the vertical axis 4003 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 4001 (i.e., x- axis). As shown, the treated substrates (curves 4007, 4009, 4011, and 4013) - other than Composition E (curve 4015) - have higher transmittance than the untreated substrate (curve 3905) for all optical wavelengths shown. Indeed, curves 4007, 4009, and 4011 (and most of curve 4013) are above 96% transmittance for optical wavelengths from about 400 nm to 2000 nm (and from 800 nm to 2000 nm). In FIG. 41, scattering (S) in % is presented on the vertical axis 4103 (i.e., y-axis) as a function of optical wavelength (X) in nanometers (nm) on the horizontal axis 4101 (i.e., x- axis). As shown, Composition A (curve 4107) has the lowest scattering, followed by Composition C (curve 4111) and Composition D (curve 4113).

[0208] Without wishing to be bound by theory, it is believed that Composition A is the most acid resistant while Composition E is the least acid resistant with the Compositions ordered from most acid resistance to least acid resistant going from Composition A to Composition E. After contact with the treatment solution maintained at 120°C for 3 days, Compositions A, C, and D had a surface roughness Sa less than 0.1 nm while Composition E had a surface roughness Sa of about 1.5 nm. In this context, the relatively poor optical properties ofComposition E (curves 3915, 4015, and 4115) can be attributed to the combination of the treatment solution and treatment conditions being too harsh for the less acid resistant Composition E. For example, a shorter treatment time (e.g., from 6 hours to 48 hours, from 12 hours to 36 hours) would be expected to produce a glass-based substrate with improved optical properties. Likewise, a lower ionic strength (e.g., from 6 to 16, from 8 to 12) would be expected to produce a glass-based substrate with improved optical properties.

[0209] As discussed above, FIG. 7 schematically shows a TEM image of a cross-sectional view of an exemplary glass-based substrate having a depletion layer 715 extending to a depletion depth 709 from the first major surface 705. Also, the interface 711 between the depletion layer 715 and the bulk 703 between extrema 716 and 718, which is described using the depth variation 719 in the depletion depth, as discussed above. Also, no detectable porosity is seen in the cross-sectional view of shown in FIG. 7.

[0210] Also, as discussed above, FIG. 8 schematically illustrates concentration profiles as measured by SIMS, where the horizontal axis 801 (e.g., x- axis) corresponds to distance (d) from the first major surface in nm and the vertical axis 803 corresponds to concentration in mol% (at the corresponding distance from the first major surface), where the concentrations were calibrated based on the known, bulk composition of the glass-based substrate being analyzed. FIG. 8 has a logarithmically scaled vertical axis (e.g., y-axis) to better show differences in small concentrations. The interface for the depletion region can be readily identified by the steep decrease in curves 815, 817, 819, and 821 (heading towards the first major surface) at around 400 nm from the first major surface. Curve 811 corresponds to a concentration profile of SiCh that appears to increase towards the first major surface due to the depletion of other components in the depletion layer. Curve 813 corresponds to a concentration profile of AI2O3 that decreases from about 10 mol% to less than 1% within the depletion layer and further decreases to about 0.1 mol% near the first major surface. Consequently, the concentration of AI2O3 within the depletion layer (e.g., 200 nm from the first major surface is less than 1%, less than 0.25 mol%, and about 0.1 mol% or less and corresponds to a concentration of less than 50%, less than 25% and less than 10% of the corresponding concentration in the bulk. Curve 815 corresponds to a concentration profile of Li2O that decreases from about 4 mol% to less than 0.01 mol% - less than 25%, less than 10%, and less than 1% of the valuein the bulk - and further decreases to less than 0.001 mol% near the first major surface. Curve 817 corresponds to a concentration profile of Na2O that decreases from about 10 mol% (i.e., 8 mol%) to less than 0.1 mol% in the depletion layer - less than 25%, less than 10%, and less than 5% of the value in the bulk - and further decreases to about 0.01 mol% near the first major surface. Consequently, concentrations of alkali metal oxides at a distance of 200 nm from the first major surface is less than 0.01 mol% and corresponds to less than 25%, less than 10%, and less than 5% of the corresponding concentration in the bulk. Curve 819 corresponds to a concentration profile of MgO that decreases from about 0.5 mol% to less than 0.1 mol% (e.g., about 0.05 mol% or less) within the depletion layer that further decreases to about 0.01 mol% near the first major surface. Consequently, concentrations of alkaline earth metal oxides in the depletion layer (e.g., at a distance of 200 nm from the first major surface) is less than 0. 1 mol% or 0.05 mol% or less corresponding to less than 25% or about 10% or less of a corresponding concentration in the bulk. Curve 821 corresponds to a concentration profile of B2O3 that decreases from about 10 mol% to less than 0.1 mol% in the depletion layer and further decreases to about 0.01 mol% near the first major surface.

[0211] FIGS. 42-43 present experimental results of properties (e.g., reflectance, scattering) for glass-based substrates having Composition C that were treated with treatment solutions having an ionic strength of 14.1 including copper chloride (CuCh) maintained at 120°C for different periods of time from 1 day (24 hours) to 7 days (168 hours). Curves 4205 and 4305 correspond to glass-based substrates that were in contact with the treatment solution for 1 day; curves 4207 and 4307 correspond to glass-based substrates that were in contact with the treatment solution for 3 days; curves 4209 and 4309 correspond to glass-based substrates that were in contact with the treatment solution for 5 days; and curves 4211 and 4311 correspond to glass-based substrates that were in contact with the treatment solution for 7 days. FIG. 42 schematically illustrates reflectance (R) in % on the vertical axis 4203 (e.g., y-axis) as a function of optical wavelength (X) in nm on the horizontal axis 4201 (e.g., x-axis). As shown, the reflectance for visual wavelengths notably decreases from curve 4205 (1 day) to curve 4207 (3 days). Indeed, curves 4205, 4207, 4209, and 4211 have an average transmittance averaged over optical wavelengths from 400 nm to 800 nm of less than 1% - indeed these curves are below 1% reflectance over this wavelength region. However, the reflectance in infraredwavelengths increased as treatment time increased (e.g., from curve 4207 (3 days) to curve 4209 (5 days) and curve 4211 (7 days)). This suggests that a treatment time of 3 days (for this treatment solution with Composition C) achieves a balance between decreasing reflectance over visual wavelengths while minimizing the increase in reflectance over infrared wavelengths. FIG. 43 schematically illustrates transmittance (T) in % on the vertical axis 4303 (e.g., y-axis) as a function of optical wavelength (X) in nanometers on the horizontal axis 4301 (e.g., x-axis). As shown, the reflectance for visual wavelengths notably increases from curve 4305 (1 day) to curve 4307 (3 days). However, the transmittance in infrared wavelengths decreased as treatment time increased (e.g., from curve 4307 (3 days) to curve 4309 (5 days) and curve 4311 (7 days)). As in FIG. 42, the results in FIG. 43 indicate that a treatment time of 3 days (for this treatment solution with Composition C) achieves a balance between increasing transmittance over visual wavelengths while minimizing the decrease in transmittance over infrared wavelengths.

[0212] FIGS. 44-45 present experimental results of properties (e.g., reflectance, scattering) for glass-based substrates having Composition C that were treated with treatment solutions having an ionic strength of 14.1 including copper chloride (CuCh) maintained at 120°C for different periods of time from 6 hours to 3 days (72 hours). Curves 4405 and 4505 correspond to glass-based substrates that were in contact with the treatment solution for 6 hours; curves 4407 and 4507 correspond to glass-based substrates that were in contact with the treatment solution for 1 day; curves 4409 and 4509 correspond to glass-based substrates that were in contact with the treatment solution for 2 days; and curves 4411 and 4511 correspond to glass-based substrates that were in contact with the treatment solution for 3 days. FIG. 44 schematically illustrates reflectance (R) in % on the vertical axis 4403 (e.g., y-axis) as a function of optical wavelength (X) in nanometers on the horizontal axis 4401 (e.g., x-axis). As shown, the reflectance notably decreases when the treatment time is increased from 6 hours (0.25 days, curve 4405) to 1 day (curve 4407) over all optical wavelengths shown. The reflectance over visual wavelengths further decreases as the treatment time is increased (e.g., from curve 4407 (1 day) to curve 4409 (2 days) and / or curve 4411 (3 days)), but the opposite trend is observed for infrared wavelengths. While there are trade-offs between these curves, it appears that a treatment time of 2 days or 3 days (see curves 4409 and 4411 - for this treatment solution with Composition C) achieves a balance between decreasing reflectance overvisual wavelengths while minimizing the increase in transmittance over infrared wavelengths.

[0213] FIG. 45 schematically illustrates transmittance (T) in % on the vertical axis 4503 (e.g., y-axis) as a function of optical wavelength (X) in nanometers on the horizontal axis 4501 (e.g., x-axis). As shown, the transmittance increases when the treatment time is increased from 6 hours (0.25 days, curve 4505) to 1 day (curve 4507), especially for infrared optical wavelengths (e.g., from 800 nm to 2000 nm).

[0214] The transmittance over visual wavelengths slightly increases as the treatment time is increased (e.g., from curve 4507 (1 day) to curve 4509 (2 days) and / or curve 4511 (3 days)), but the opposite trend is observed for infrared wavelengths. While there are trade-offs between these curves, it appears that a treatment time of 1 day or 2 days (see curves 4507 and 4509 - for this treatment solution with Composition C) achieves a balance between decreasing reflectance over visual wavelengths while minimizing the increase in transmittance over infrared wavelengths. Combining the results in FIGS. 44-45, it appears that a treatment time of 2 days achieves the best optical properties (for this treatment solution with Composition C).

[0215] The above observations can be combined to provide glass-based substrates and methods of making the same having a depletion layer extending from the first major surface. Providing a depletion layer can provide enhanced optical properties, including one or more of reduced reflectance, reduced scattering, and / or increased transmittance over visual and / or infrared optical wavelengths. Without wishing to be bound by theory, the depletion thickness can roughly correspond to a maximum wavelength where the glass-based substrate with the depletion layer reliably exhibits excelled anti-reflective properties (which is supported by the results discussed with reference to FIG. 12). For example, glass-based substrates having a depletion layer with a depletion thickness of 760 nm or more (e.g., 800 nm or more, 1.0 pm or more) are expected to have anti-reflective properties over the visual spectrum (e.g., optical wavelengths from 380 nm to 760 nm, from 400 nm to 700 nm).

[0216] To the extent that all light incident on the first major surface can be accounted for through the combination of transmittance, reflectance, scattering, and absorption - for the optical wavelengths discussed in this application, it is believed that absorption is negligible for substrate thicknesses less than 1 mm. Consequently, decreasing reflectance and / or scattering is believed to increase transmittance. Also, aproxy for scatering can be estimated as 100% - (T + R), where T is transmittance and R is reflectance at a predetermined optical wavelength (or averaged over a predetermined range of optical wavelengths). Providing the depletion layer in the glass-based substrate can provide increased transmitance (e.g., greater than an untreated glass-based substrate without the depletion layer but otherwise identical greater than or equal to 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, or more), decreased reflectance, and / or decreased scatering.

[0217] As demonstrated by the Examples herein, it is the combination of pH and ionic strength that allows the treatment solution to form the depletion layer within the ranges disclosed herein. FIG. 24 demonstrates that the ionic strength of the treatment solution alone is not sufficient to produce antireflective articles. FIG. 25 demonstrates that the pH of the treatment solution alone is not sufficient to produce antireflective articles. Rather, the combination of pH and ionic strength should be selected based on the acid resistance of the glass-based substrate and the time that the treatment solution will contact the glass-based substrate. The ionic strength of the treatment solution can be from 6 to 24, from 8 to 20, or from 10 to 16. Also, the pH of the treatment solution can be from 0.3 to 3.2 or from 0.5 to 1.5.

[0218] Directional terms as used herein — for example, up, down, right, left, front, back, top, botom — are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0219] It will be appreciated that the various disclosed aspects may involve features, elements, or steps that are described in connection with that aspect. It will also be appreciated that a feature, element, or step, although described in relation to one aspect, may be interchanged or combined with alternate aspects in various nonillustrated combinations or permutations.

[0220] It is also to be understood that, as used herein the terms “the,” “a,” or “an,” mean “at least one,” and should not be limited to “only one” unless explicitly indicated to the contrary. For example, reference to “a component” comprises aspects having two or more such components unless the context clearly indicates otherwise. Likewise, a “plurality” is intended to denote “more than one.”

[0221] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error, and the like, andother factors known to those of skill in the art. Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, aspects include from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. Whether or not a numerical value or endpoint of a range in the specification recites “about,” the numerical value or endpoint of a range is intended to include two aspects: one modified by “about,” and one not modified by “about.” It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint and independently of the other endpoint.

[0222] The terms “substantial,” “substantially,” and variations thereof as used herein are intended to note that a described feature is equal or approximately equal to a value or description. For example, a “substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, as defined above, “substantially similar” is intended to denote that two values are equal or approximately equal. In aspects, “substantially similar” may denote values within about 10% of each other, for example, within about 5% of each other, or within about 2% of each other.

[0223] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that any particular order be inferred.

[0224] While various features, elements, or steps of particular aspects may be disclosed using the transitional phrase “comprising,” it is to be understood that alternative aspects, including those that may be described using the transitional phrases “consisting of’ or “consisting essentially of,” are implied. Thus, for example, implied alternative aspects to an apparatus that comprises A+B+C include aspects where an apparatus consists of A+B+C and aspects where an apparatus consists essentially of A+B+C. As used herein, the terms “comprising” and “including”, and variations thereof shall be construed as synonymous and open-ended unless otherwise indicated.

[0225] The above aspects, and the features of those aspects, are exemplary and can be provided alone or in any combination with any one or more features of other aspects provided herein without departing from the scope of the disclosure.

[0226] It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of the aspects herein provided they come within the scope of the appended claims and their equivalents.

Claims

1. What is claimed is:

1. A glass-based substrate comprising: a depletion layer extending from a first major surface to a first depth from the first major surface, the depletion layer is depleted in one or more alkali metal oxide, alkaline earth metal oxide, alumina, or combinations thereof relative to a bulk of the glass-based substrate, and the first depth is from 300 nanometers to 10.0 micrometers, wherein the glass-based substrate exhibits a total reflectance averaged over optical wavelengths from 400 nanometers to 800 nanometers of light incident on the first major surface is from 0.1% to 2.0%, and a porosity of the first major surface is less than or equal to 1.0%.

2. The glass-based substrate of claim 1, wherein the first depth is from 800 nanometers to 2.0 micrometers.

3. The glass-based substrate of any one of claims 1-2, wherein the first depth corresponds to an average depth that the depletion layer extends from the first major surface, and a depth variation of the depletion layer is from 50 nanometers to 600 nanometers.

4. The glass-based substrate of any one of claims 1-3, wherein the glass-based substrate exhibits the total reflectance averaged over optical wavelengths from 400 nanometers to 800 nanometers of light incident on the first major surface is from 0.1% to 1.0%.

5. The glass-based substrate of any one of claims 1-3, wherein the glass-based substrate exhibits a total reflectance averaged over optical wavelengths from 800 nanometers to 2000 nanometers of light incident on the first major surface is from 0.1% to 2.0%.

6. The glass-based substrate of any one of claims 1-5, wherein the glass-based substrate exhibits a total transmittance averaged over optical wavelengths from 400 nanometers to 800 nanometers is from 94% to 100%.

7. The glass-based substrate of any one of claims 1-5, wherein the glass-based substrate exhibits a total transmittance averaged over optical wavelengths from 800 nanometers to 2000 nanometers is from 94% to 100%.

8. The glass-based substrate of any one of claims 1-7, wherein the glass-based substrate exhibits a scattering of the first major surface averaged over optical wavelengths from 400 nanometers to 800 nanometers from 0. 1% to 5.0%.

9. The glass-based substrate of any one of claims 1-7, wherein a second porosity of a cross-section perpendicular to the first major surface is less than or equal to 1.0%.

10. The glass-based substrate of any one of claims 1-9, wherein a concentration of alumina at 200 nanometers from the first major surface is less than or equal to 10 mol%.

11. The glass-based substrate of any one of claims 1-9, wherein a concentration of alumina at 200 nanometers from the first major surface is less than or equal to 50% of a concentration of alumina in the bulk.

12. The glass-based substrate of any one of claims 1-11, wherein a concentration of alumina at 200 nanometers from the first major surface is less than or equal to 0.1 mol%.

13. The glass-based substrate of any one of claims 1-12, wherein a concentration of the one or more alkali metal oxide at 200 nanometers from the first major surface is less than or equal to 25% of a corresponding concentration of the one or more alkali metal oxide in the bulk.

14. The glass-based substrate of any one of claims 1-12, wherein a concentration of the one or more alkali metal oxide at 200 nanometers from the first major surface is less than or equal to 0. 1 mol%.

15. The glass-based substrate of any one of claims 1-14, wherein a concentration of one or more alkaline earth metal oxides at 200 nanometers from the first majorsurface is less than or equal to 25% of a corresponding concentration of the one or more alkaline earth metal oxides in the bulk.

16. The glass-based substrate of any one of claims 1-14, wherein a concentration of boron at 200 nanometers from the first major surface is less than or equal to 25% of a corresponding concentration of the boron in the bulk.

17. The glass-based substrate of any one of claims 1-16, wherein: a concentration of chloride at 200 nanometers from the first major surface is greater than or equal to 10'3mol%; or a concentration of copper at 200 nanometers from the first major surface is greater than or equal to 10'4mol%; or a concentration of zinc at 200 nanometers from the first major surface is greater than or equal to 10'4mol%.

18. A consumer electronic product comprising : a housing comprising a front surface, a back surface, and a side surface; electrical components at least partially within the housing, the electrical components comprising a controller, a memory, and a display, the display at or adjacent the front surface of the housing; and a cover substrate disposed over the display, wherein at least one of a portion of the housing comprises the glass-based substrate of any one of claims 1-17.

19. A method of treating a glass-based substrate comprising: contacting a first major surface of the glass-based substrate with a treatment solution maintained at a first temperature for a first period of time to form a depletion layer extending from a first major surface to a first depth from the first major surface, the first temperature is from 80°C to 180°C, depletion depth and the first period of time is from 1 hour to 168 hours, and the first depth is from 300 nanometers to 10.0 micrometers, wherein a porosity of the first major surface is less than or equal to 1.0%.

20. The method of claim 19, wherein a pH of the treatment solution is from 0.3 to3.2.

21. The method of any one of claims 19-20, wherein an ionic strength of the treatment solution is from 6 to 24.

22. The method of claim 21, wherein the ionic strength is from 12 to 16.

23. The method of any one of claims 19-22, wherein treatment solution comprises one or more of copper ions or zinc ions, and the treatment solution comprises one or more of chloride ions or nitrate ions.

24. The method of any one of claims 19-23, wherein the treatment solution further comprises from 10'4wt% to 3 wt% of polyethylene glycol).

25. The method of any one of claims 19-24, wherein the first depth corresponds to an average depth that the depletion layer extends from the first major surface, and a depth variation of the depletion layer is from 50 nanometers to 600 nanometers.

26. The method of any one of claims 19-25, wherein the glass-based substrate having the depletion layer exhibits: a total reflectance averaged over optical wavelengths from 400 nanometers to 800 nanometers of light incident on the first major surface is from 0.1% to 2.0%; a total reflectance averaged over optical wavelengths from 800 nanometers to 2000 nanometers of light incident on the first major surface is from 0. 1% to 2.0%; or both.

27. The method of any one of claims 19-26, wherein the glass-based substrate having the depletion layer exhibits: a total transmittance averaged over optical wavelengths from 400 nanometers to 800 nanometers is from 94% to 100%; a total transmittance averaged over optical wavelengths from 800 nanometers to 2000 nanometers is from 94% to 100%; or both28. The method of any one of claims 19-27, wherein the glass-based substrate having the depletion layer exhibits: a scattering of the first major surface averaged over optical wavelengths from 400 nanometers to 800 nanometers from 0. 1% to 5.0%; a scattering of the first major surface averaged over optical wavelengths from 400 nanometers to 800 nanometers from 0. 1% to 2.0%; or both.

29. The method of any one of claims 19-28, wherein a second porosity of a crosssection perpendicular to the first major surface is less than or equal to 1 .0%.

30. The method of any one of claims 19-29, wherein the method produces the glass-based substrate of any one of claims 1-18.

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