Glass sheet with a cerium-containing crystalline phase

Abstract

A glass sheet including a glass phase including a glass composition; and a primary crystalline phase dispersed within the glass phase, the primary crystalline phase including cerium atoms, a majority of which have a +3 oxidation state. The primary crystalline phase can be aeschynite. A photovoltaic module including one or more photovoltaic cells; and a cover sheet including the glass sheet disposed between the one or more photovoltaic cells and an external environment. An architectural window including a first pane including the glass sheet; and a second pane separated from the first pane by a space. The primary crystalline phase can be present within the glass phase before separation of the glass sheet from a ribbon of glass formed from delivering molten glass to a mold. A subsequent heat treatment step can cause the primary crystalline phase to form in the glass sheet.

Description

Attorney Docket No. SP24-286PCT GLASS SHEET WITH A CERIUM-CONTAINING CRYSTALLINE PHASE BACKGROUND

[0001] This application claims the benefit of priority under 35 U. S. C. § 119 of U. S. Provisional Application No. 63 / 724,521 filed November 25, 2024, the content of which is incorporated herein by reference in its entirety.

[0002] Artificial satellites, such as those that orbit Earth, often have a need to generate electrical power. Some satellites include photovoltaic cells to transform energy from the Sun into electrical power. In such instances, a cover sheet separates the photovoltaic cells from the external environment.

[0003] However, there are several problems. First, ultraviolet light degrades the photovoltaic cells. As the photovoltaic cells degrade, the efficiency in converting energy from the Sun to electrical power that the photovoltaic cells exhibit decreases. The decreased efficiency is problematic because eventually the photovoltaic cells will not produce sufficient electrical energy for the satellite to perform its function. The satellite must then be deorbited. Second, the cover sheet adds weight to the satellite. That is problematic because the cost required to move the satellite from Earth to orbit increases as the weight of the satellite increases. Thus, there is an incentive to reduce the weight of the cover glass.SUMMARY

[0004] The present disclosure addresses those problems, among others, with a glass sheet that includes both a glass phase and a primary crystalline phase that includes cerium atoms predominately with a +3 oxidation state. Cerium atoms having the +3 oxidation state absorb ultraviolet wavelengths of electromagnetic radiation better than cerium atoms of other oxidation states. When cerium atoms form part of certain crystalline phases, such as aechynite, the cerium atoms are forced to take the +3 oxidation state. In contrast, when cerium atoms are part of the glass phase, such as when crystallization has not occurred, the cerium atoms are more likely to take oxidation states other than +3 (e.g., +4). The glass sheet can be manipulated during manufacture thereof so that the desired cerium-containing crystalline phase forms. Because the cerium atoms have the +3 oxidation state, the glass sheet absorbs ultraviolet wavelengths of electromagnetic radiation more optimally and thus protect photovoltaic cells better than cover sheets that include cerium atoms of other oxidation states. Further, because the cerium atoms are forced into the +3 oxidation state, less cerium-containing raw materials need to be utilized to form the cover sheet, which means that the cover sheet can be made thinner, with less weight, and with less cost than other cover sheets that include cerium.Attorney Docket No. SP24-286PCT

[0005] According to a first aspect of the present disclosure, a glass sheet comprises: (a) a glass phase comprising a glass composition; and (b) a primary crystalline phase dispersed within the glass phase, the primary crystalline phase comprising cerium atoms, a majority of which have a +3 oxidation state.

[0006] According to a second aspect of the present disclosure, the glass sheet of the first aspect further comprises: a sheet thickness within a range of from 40 pm to 200 pm.

[0007] According to a third aspect of the present disclosure, the glass sheet of any one of the first through second aspects further is presented, wherein the glass composition comprises (in mol%, on an oxide basis): from 73.0 to 78.0 SiO2; from 4.00 to 8.00 Al2O3; from 2.00 to 3.50 MgO; from 1.50 to 4.00 CaO; from 7.00 to 12.50 Na2O; from 0.20 to 3.00 TiO2; and from 0.20 to 2.00 CeO2.

[0008] According to a fourth aspect of the present disclosure, the glass sheet of the third aspect is presented, wherein the glass composition comprises from 0.59 to 2.00 CeO2.

[0009] According to a fifth aspect of the present disclosure, the glass sheet of any one of the third through fourth aspects is presented, wherein the glass composition comprises from >0 to 1.50 ZnO.

[0010] According to a sixth aspect of the present disclosure, the glass sheet of any one of the third through fifth aspects is presented, wherein the glass composition comprises from >0 to 4.00 K2O.

[0011] According to a seventh aspect of the present disclosure, the glass sheet of any one of the third through sixth aspects is presented, wherein the glass composition comprises from >0 to 0.50 SnO2.

[0012] According to an eighth aspect of the present disclosure, the glass sheet of any one of the first through seventh aspects is presented, wherein the primary crystalline phase is aeschynite.

[0013] According to a ninth aspect of the present disclosure, the glass sheet of any one of the first through eighth aspects is presented, wherein the primary crystalline phase further comprises atoms of calcium, titanium, and oxygen.

[0014] According to a tenth aspect of the present disclosure, the glass sheet of any one of the first through ninth aspects further comprises a secondary crystalline phase dispersed within the glass phase, wherein, the secondary crystalline phase comprises one or more of rutile and diopside.Attorney Docket No. SP24-286PCT

[0015] According to an eleventh aspect of the present disclosure, the glass sheet of any one of the first through tenth aspects is presented, wherein the glass sheet exhibits a density within a range of from 2.430 g / cm3to 2.550 g / cm3.

[0016] According to a twelfth aspect of the present disclosure, the glass sheet of any one of the first through eleventh aspects is presented, wherein the glass sheet exhibits a coefficient of thermal expansion within a range of from 6.20 ppm / °C to 7.50 ppm / °C.

[0017] According to a thirteenth aspect of the present disclosure, the glass sheet of any one of the first through twelfth aspects is presented, wherein the glass sheet exhibits an internal liquidus temperature that is greater than a temperature at which the glass sheet exhibits a viscosity of 120,000 Poise.

[0018] According to a fourteenth aspect of the present disclosure, a photovoltaic module comprises: (a) one or more photovoltaic cells; and (b) the glass sheet of any one of the first through thirteenth aspects disposed between the one or more photovoltaic cells and an external environment.

[0019] According to a fifteenth aspect of the present disclosure, the photovoltaic module of the fourteenth aspect further comprises: an encapsulant at least partially encapsulating the one or more photovoltaic cells.

[0020] According to a sixteenth aspect of the present disclosure, an architectural window comprises: (a) a first pane comprising the glass sheet of any one of the first through thirteenth aspects; and (b) a second pane separated from the first pane by a space.

[0021] According to a seventeenth aspect of the present disclosure, the architectural window of the sixteenth aspect further comprises a frame surrounding perimeters of both the first pane and the second pane.

[0022] According to an eighteenth aspect of the present disclosure, a method of making a glass sheet, the method comprising: a delivery step comprising delivering a glass composition in molten form to a mold, the glass composition comprising cerium atoms; a formation step comprising molding the glass composition into a glass ribbon; and a separation step comprising separating a glass sheet from the glass ribbon, wherein, the glass sheet comprises: (a) a glass phase comprising a glass composition; and (b) a primary crystalline phase dispersed within the glass phase, the primary crystalline phase comprising cerium atoms, a majority of which have a +3 oxidation state.

[0023] According to a nineteenth aspect of the present disclosure, the method of the eighteenth aspect is presented, wherein the primary crystalline phase is present within the glass phase before the separation step occurs.Attorney Docket No. SP24-286PCT

[0024] According to a twentieth aspect of the present disclosure, the method of any one of the eighteenth through nineteenth aspects is presented, wherein the primary crystalline phase is formed during the formation step.

[0025] According to a twenty-first aspect of the present disclosure, the method of the eighteenth aspect is presented, wherein a heat treatment step occurs after the formation step to cause the primary crystalline phase to form within the glass phase.

[0026] According to a twenty-second aspect of the present disclosure, the method of the twenty-first aspect is presented, wherein the heat treatment step occurs before the separation step.

[0027] According to a twenty-third aspect of the present disclosure, the method of the twenty first aspect is presented, wherein the heat treatment step occurs after the separation step.

[0028] According to a twenty-fourth aspect of the present disclosure, the method of any one of the twentieth through twenty-third aspects is presented, wherein the glass composition comprises (in mol%, on an oxide basis): from 73.0 to 78.0 SiO2; from 4.00 to 8.00 Al2O3; from 2.00 to 3.50 MgO; from 1.50 to 4.00 CaO; from 7.00 to 12.50 Na2O; from 0.20 to 3.00 TiO2; and from 0.20 to 2.00 CeO2.

[0029] Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.

[0030] It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiments, and together with the description serve to explain principles and operation of the various embodiments.BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In the Drawings:

[0032] FIG. 1 is perspective view of a glass sheet of the present disclosure, illustrating a primary crystalline phase disposed throughout a glass phase;

[0033] FIG. 2 is a perspective view of a photovoltaic module that includes the glass sheet as a cover sheet through which photons from the Sun transmit to reach a photovoltaic cell;

[0034] FIG. 3 is a plan view of the photovoltaic module, illustrating a frame holding a package that includes the glass sheet as the cover sheet;Attorney Docket No. SP24-286PCT

[0035] FIG. 4 is an elevational view of a cross-section of the photovoltaic module, illustrating the package further including a backsheet, which may be another glass sheet of the present disclosure;

[0036] FIG. 5 is a magnified view of area V of FIG. 4, illustrating the package further including an encapsulant encapsulating the photovoltaic cells between the cover sheet and the backsheet;

[0037] FIG. 6 is an elevational view of an architectural window that incorporates the glass sheet as part of a first pane;

[0038] FIG. 7 is a partial elevational view of a cross-section of the architectural window taken through line VII- VII of FIG. 6, illustrating the first pane incorporating the glass sheet as part of a laminate structure and separated from a second pane by a space; and

[0039] FIG. 8 is a schematic diagram of a method of making the glass sheet of the present disclosure, illustrating a delivery step, a formation step, a separation step, and optionally a heat treatment step to force the crystallization of the primary crystalline phase if the same was not formed before the separation step.DETAILED DESCRIPTION

[0040] Reference will now be made in detail to the present preferred embodiments, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts.

[0041] Referring to FIG. 1, a glass sheet 10 includes a first primary surface 12 and a second primary surface 14. The first primary surface 12 and the second primary surface 14 face in opposite directions 16, 18. The glass sheet 10 has a sheet thickness 20 measured orthogonally to the first primary surface 12 between the first primary surface 12 and the second primary surface 14. In embodiments, the sheet thickness 20 is within a range of from 40 pm to 200 pm. For example, the sheet thickness 20 can be 40 pm, 50 pm, 60 pm, 70 pm, 80 pm, 90 pm, 100 pm, 110 pm, 120 pm, 130 pm, 140 pm, 150 pm, 160 pm, 170 pm, 180 pm, 190 pm, 200 pm, or within any range bound by any two of those values (e.g., from 50 pm to 190 pm, from 110 pm to 140 pm, and so on). Values for the sheet thickness 20 of less than 40 pm and greater than 200 pm are envisioned.

[0042] The glass sheet 10 is glass-based. The glass sheet 10 is at least bi-phasic with a glass phase 22 and a primary crystalline phase 24. The primary crystalline phase 24 is dispersed within the glass phase 22. The glass sheet 10 includes more of the glass phase 22 than the primary crystalline phase 24 by weight. The glass phase 22 can be thought of as a matrix and the primary crystalline phase 24 is dispersed as particles within the matrix. The primaryAttorney Docket No. SP24-286PCT crystalline phase 24 includes cerium (Ce) atoms. The majority of the Ce atoms have a +3 oxidation state rather than, for example, a +4 oxidation state.

[0043] In embodiments, the glass composition includes (in mole percentage and on an oxide basis) from 73.0 to 78.0 SiO2; from 4.00 to 8.00 Al2O3; from 2.00 to 3.50 MgO; from 1.50 to 4.00 CaO; from 7.00 to 12.50 Na2O; from 0.20 to 3.00 TiO2; and from 0.20 to 2.00 CeC>2. The glass composition as described can be considered as analyzed after formation of the glass sheet 10 or as batched before the glass composition is formed. Other glass compositions that result in the formation of the primary crystalline phase 24 as described with Ce atoms having the +3 oxidation state are envisioned. The glass composition can include other constituents than those listed. For example, the glass composition can include one or more of ZnO, K2O, and SnO2.

[0044] Silicon dioxide, SiO2, is the primary glass former of the glass composition. The glass composition, as mentioned, can include from 73.0 mol% to 78.0 mol% SiO2. For example, the glass composition can include a mole percentage of SiO2of 73.0, 73.5, 74.0, 74.5, 75.0, 75.5, 76.0, 76.5, 77.0, 77.5, 78.0, or within any range bound by any two of those values (e.g., from 73.5 to 77.5, from 74.0 to 76.5, and so on).

[0045] Alumina, Al2O3, is another glass former present in the glass composition. The glass composition, as mentioned, can include from 4.00 mol% to 8.00 mol% Al2O3. For example, the glass composition can include a mole percentage of Al2O3of 4.00, 4.25, 4.50, 4.75, 5.00, 5.25, 5.50, 5.75, 6.00, 6.25, 6.50, 6.75, 7.00, 7.25, 7.50, 7.75, 8.00, or within any range bound by any two of those values (e.g., from 4.25 to 7.75, from 4.50 to 6.50, and so on).

[0046] Magnesium oxide, MgO, can be present as a modifier in the glass composition. The glass composition, as mentioned, can include from 2.00 to 3.50 MgO. For example, the glass composition can include a mole percentage of MgO of 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, 3.10, 3.20, 3.30, 3.40, 3.50, or within any range bound by any two of those values (e.g., from 2.10 to 3.40, from 2.40 to 3.10, and so on).

[0047] Calcium oxide, CaO, can be present as a modifier in the glass composition. The glass composition, as mentioned, can include from 1.50 to 3.50 CaO. For example, the glass composition can include a mole percentage of 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, 3.10, 3.20, 3.30, 3.40, 3.50, or within any range bound by any two of those values (e.g., from 1.60 to 3.60, from 1.80 to 2.80, and so on).

[0048] Sodium oxide, Na2O, can be present as a modifier in the glass composition. The glass composition, as mentioned, can include from 7.00 to 12.50 Na2O. For example, the glass composition can include a mole percentage of Na2O of 7.00, 7.25, 7.50, 7.75, 8.00, 8.25, 8.50, 8.75, 9.00, 9.25, 9.50, 9.75, 10.00, 10.25, 10.50, 10.75, 11.00, 11.25, 11.50, 11.75, 12.00,Attorney Docket No. SP24-286PCT 12.25, 12.50, or within any range bound by any two of those values (e.g., from 7.50 to 11.00, from 10.50 to 12.25, and so on).

[0049] Titanium dioxide, TiO2, can be present as a glass former and / or a modifier in the glass composition. In particular, the presence of TiO2in the glass composition can absorb ultraviolet radiation and thus lower transmittance of ultraviolet radiation though the glass sheet 10. In particular, titanium absorbs electromagnetic radiation primarily of wavelengths within a range of from 290 nm to 300 nm. The glass composition, as mentioned, can include from 0.20 to 3.00 TiC>2. For example, the glass composition can include a mole percentage of TiO2of 0.20, 0.40, 0.60, 0.70, 0.80, 1.00, 1.20, 1.40, 1.60, 1.70, 1.80, 2.00, 2.10, 2.20, 2.40, 2.50, 2.60, 2.70, 2.80, 3.00, or within any range bound by any two of those values (e.g., from 0.10 to 2.70, from 0.70 to 2.90, and so on).

[0050] Cerium oxide, CeO2, can be present as a modifier, and a fining agent, in the glass composition as batched so that Ce forms part of the primary crystalline phase 24. The presence of CeO2in the glass composition, and Ce in the primary crystalline phase 24, can absorb ultraviolet radiation and thus lower transmittance of ultraviolet radiation though the glass sheet 10. In particular, the primary crystalline phase 24 forces most of the Ce to take the +3 oxidation state. In the 3+ oxidation state, Ce absorbs wavelengths of electromagnetic radiation primarily within the range of from 300 nm to 320 nm, which cooperates well with titanium’s absorption within the range of from 290 nm to 300 nm. In contrast, in the +4 oxidation state, Ce absorbs electromagnetic radiation primarily within a range centered at about 240 nm, which is less desirable for the present purposes than the range of from 290 nm to 320 nm. The glass composition, as mentioned, can include from 0.20 to 2.00 CeO2. For example, the glass composition can include a mole percentage of CeO2of 0.20, 0.30, 0.40, 0.50, 0.59, 0.60, 0.70, 0.80, 0.90, 1.00, 1.10, 1.20, 1.30, 1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, or within any range bound by any two of those values (e.g., from 1.00 to 2.00, from 0.40 to 1.70, from 0.50 to 0.90, from 0.59 to 2.00, and so on). The CeO2may be present in the mole percentages stated herein in the glass phase 22.

[0051] Zinc oxide, ZnO, can be present as a glass former and / or a modifier in the glass composition. In particular, the presence of ZnO in the glass composition can absorb ultraviolet radiation and thus lower transmittance of ultraviolet radiation though the glass sheet 10. The composition can include from greater than 0 to 1.50 ZnO. For example, the glass composition can include a mole percentage of ZnO of 0, greater than 0, 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.10, 1.20, 1.30, 1.40, 1.50, or within any range bound by any two ofAttorney Docket No. SP24-286PCT those values (e.g., from 0 to 1.20, from 0.50 to 0.80, and so on). The glass composition can be substantially free, or free, of ZnO.

[0052] Potassium oxide, K2O, can be present as a modifier in the glass composition. The composition can include from greater than 0 to 4.00 K2O. For example, the composition can include a mole percentage of K2O of 0, greater than 0, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, 2.75, 3.00, 3.25, 3.50, 3.75, 4.00, or within any range bound by any two of those values (e.g., from greater than 0 to 1.00, from 0.25 to 0.50, and so on). The composition can be substantially free, or free, of K2O.

[0053] Tin dioxide, SnO2, can be present as a glass former, a fining agent, and / or a modifier in the glass composition. The glass composition can include from 0 to 0.50 SnC>2. For example, the composition can include a mole percentage of SnO2of 0, greater than 0, 0.10, 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24, 0.26, 0.28, 0.30, 0.32, 0.34, 0.36, 0.38, 0.40, 0.42, 0.44, 0.46, 0.48, 0.50, or within any range bound by any two of those values (e.g., from 0.12 to 0.46, from greater than 0 to 0.30, and so on). The composition can be substantially free, or free, of SnO2.

[0054] As mentioned, the primary crystalline phase 24 of the glass sheet 10 includes Ce atoms, the majority of which are in a +3 oxidation state. In embodiments, the primary crystalline phase 24 is aeschynite. Atoms of Ce take a +3 oxidation state when participating in the formation of aeschynite. In nature, the mineral aeschynite includes Th, Fe, and Nb. However, Th, Fe, and Nb need not be present for the primary crystalline phase 24 to be characterized as aeschynite. X-ray diffraction can be utilized to identify the nature of the primary crystalline phase 24 and a judgment can be made that the primary crystalline phase 24 is best described as aeschynite rather than some other Ce-containing crystal structure. In embodiments, the primary crystalline phase 24 includes atoms of one or more of calcium, titanium, and oxygen. With aeschynite, at least the form found in nature, about 89% of the Ce atoms take the +3 oxidation state. Other natural Ce-containing crystalline forms include britholite and monazite, which include 70% and 100% of the Ce atoms therein in the +3 oxidation state. The primary crystalline phase 24 of the present disclosure could include Ce-containing crystalline phases that are best categorized as britholite or monazite (as alternatives to aeschynite).

[0055] The glass sheet 10 can include other crystalline phases. For example, the glass sheet 10 can include a secondary crystalline phase. The secondary crystalline phase, if present, is dispersed within the glass phase 22. In embodiments, the secondary crystalline phase is rutile. Rutile is one of the crystalline forms of TiO2. In embodiments, the secondary crystalline phase is diopside. Diopside in nature is MgCaSi2Oe and the secondary crystalline phase of the glass sheet 10 characterized as diopside can have the same or similar composition. The glass sheetAttorney Docket No. SP24-286PCT 10 can include both rutile and diopside as separate secondary crystalline phases. X-ray diffraction again can be utilized to characterize the identity of the secondary crystalline phase.

[0056] The glass sheet 10 has beneficial properties. For example, the glass sheet 10 can exhibit a beneficial density. In embodiments, the density that the glass sheet 10 exhibits is within a range of from 2.430 g / cm3to 2.550 g / cm3. For example, the density that the glass sheet 10 exhibits can be 2.430 g / cm3, 2.440 g / cm3, 2.450 g / cm3, 2.460 g / cm3, 2.470 g / cm3, 2.480 g / cm3, 2.490 g / cm3, 2.500 g / cm3, 2.510 g / cm3, 2.520 g / cm3, 2.530 g / cm3, 2.540 g / cm3, 2.550 g / cm3, or within any range bound by any two of those values (e.g., from 2.440 g / cm3to 2.530 g / cm3, from 2.450 g / cm3to 2.540 g / cm3, and so on).

[0057] The glass sheet 10 can exhibit a beneficial coefficient of thermal expansion (CTE). The CTE that glass sheet 10 exhibits can be within range of from 6.20 ppm / °C to 7.50 ppm / °C. For example, the CTE that the glass sheet 10 exhibits can be 6.20 ppm / °C, 6.30 ppm / °C, 6.40 ppm / °C, 6.50 ppm / °C, 6.60 ppm / °C, 6.70 ppm / °C, 6.80 ppm / °C, 6.90 ppm / °C, 7.00 ppm / °C, 7.10 ppm / °C, 7.20 ppm / °C, 7.30 ppm / °C, 7.40 ppm / °C, 7.50 ppm / °C, or within any range bound by any two of those values (e.g., from 6.30 ppm / °C to 7.20 ppm / °C, from 6.50 ppm / °C to 7.30 ppm / °C, and so on).

[0058] The glass sheet 10 can exhibit an internal liquidus temperature that is within a range of from 920 °C to 1200 °C. For example, the internal liquidus temperature that the glass sheet 10 exhibits can be 920 °C, 940 °C, 960 °C, 980 °C, 1000 °C, 1020 °C, 1040 °C, 1060 °C, 1080 °C, 1100 °C, 1120 °C, 1140 °C, 1160 °C, 1180 °C, 1200 °C, or within any range bound by any two of those values (e.g., from 960 °C to 1180 °C, from 1000 °C to 1160 °C, and so on). In embodiments, the internal liquidus temperature that the glass sheet 10 exhibits is greater than the temperature at which the glass sheet 10 exhibits a viscosity of 120,000 Poise. The viscosity of 120,000 Poise is notable because that is the viscosity at which the glass composition is delivered to a slot draw forming apparatus to form the glass sheet 10. When the internal liquidus temperature is greater than the temperature at which the glass sheet 10 exhibits a viscosity of 120,000 Poise, the primary crystalline phase 24 and the secondary crystalline phase(s) can be present. In short, the glass sheet 10 is formed upon draw with the primary crystalline phase 24 and the secondary crystalline phase(s) present. A subsequent heat treatment of the glass sheet 10 is unnecessary to precipitate the primary crystalline phase 24 and the secondary crystalline phase(s) within the glass phase 22.

[0059] Referring now to FIGS. 2-5, a photovoltaic module 100 includes a cover sheet 102 and one or more photovoltaic cells 104 disposed beneath the cover sheet 102. The cover sheet 102 includes the glass sheet 10. In embodiments, the glass sheet 10 is the cover sheet 102. In otherAttorney Docket No. SP24-286PCT embodiments, the glass sheet 10 is a layer of the cover sheet 102, such as a laminate structure. The one or more photovoltaic cells 104 is disposed beneath a first primary surface 106 or a second primary surface 108 of the cover sheet 102. The cover sheet 102 separates the one or more photovoltaic cells 104 from an external environment 110.

[0060] During use of the photovoltaic module 100, photons 112 from the Sun 114 enter the photovoltaic module 100 through the cover sheet 102 and impinge upon the one or more photovoltaic cells 104. The type of photovoltaic cells 104 is not particularly limited, though in preferred embodiments, the one or more photovoltaic cells 104 includes monocrystalline silicon.

[0061] In embodiments, the photovoltaic module 100 further includes a backsheet 116. The one or more photovoltaic cells 104 is disposed between the cover sheet 102 and the backsheet 116. The backsheet 116 can have a glass composition and, indeed, can also be or include the glass sheet 10 of the present disclosure. Stated another way, the glass sheet 10 of the present disclosure can be the cover sheet 102 of the photovoltaic module 100 (or a layer thereof) and another glass sheet 10 of the present disclosure can be the backsheet 116 of the photovoltaic module 100 (or a layer thereof).

[0062] Having the one or more photovoltaic cells 104 sandwiched between the cover sheet 102 and the backsheet 116 allows the one or more photovoltaic cells 104 to receive photons 112 transmitting through both the cover sheet 102 and the backsheet 116. That arrangement in theory should increase the electricity production of the photovoltaic module 100 compared to if the one or more photovoltaic cells 104 received photons 112 transmitting only through the cover sheet 102 but not the backsheet 116.

[0063] In embodiments, an encapsulant 118 at least partially encapsulates the one or more photovoltaic cells 104. The encapsulant 118 at least partially encapsulates the one or more photovoltaic cells 104 between the cover sheet 102 and the backsheet 116. The cover sheet 102 and the backsheet 116 thus separate the one or more photovoltaic cells 104 and the encapsulant 118 from the external environment 110. The encapsulant 118 has a composition, e.g., material that forms the encapsulant 118. In embodiments, the composition of the encapsulant 118 is one or more of ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB), a silicone-based material (e.g., SYLGARD™ 184), an ionomer (e.g., DUPONT's® PV5400, PV5300, PV5200, or PV8600), a thermoplastic polyolefin (TPO) (e.g., Quentys™ BPO from Borealis), and a polyolefin elastomer (POE) (e.g., Engage™ from Dow). Other compositions for the encapsulant 118 are envisioned.Attorney Docket No. SP24-286PCT

[0064] In embodiments, the photovoltaic module 100 further includes a frame 120. When the photovoltaic module 100 is oriented horizontally, such that the first primary surface 106 of the cover sheet 102 is horizontal and facing upwards, the frame 120 defines a top 122 and a bottom 124 of the photovoltaic module 100 where the top 122 is the most elevated portion of the photovoltaic module 100 and the bottom 124 is the least elevated portion of the photovoltaic module 100, excluding wiring that may extend from the photovoltaic module 100. In a more detailed example, the frame 120 includes a sidewall 126, a C-channel 128 that is contiguous with the sidewall 126, and a tab 130 that extends inward relative to the sidewall 126. The C-channel 128 is disposed at or near the top 122 of the frame 120, and the tab 130 is disposed at or near the bottom 124 of the frame 120. The tab 130 forms a plane 132 that is generally parallel to an outward primary surface 134 of the backsheet 116. The cover sheet 102, the one or more photovoltaic cells 104, and the backsheet 116 are all coupled to each other as a package 136. The sidewall 126 extends around a perimeter 138 of the package 136 with the perimeter 138 of the package 136 secured within the C-channel 128 of the frame 120.

[0065] Referring now to FIGS. 6 and 7, an architectural window 200 including the cover sheet 102 is herein disclosed. The architectural window 200 includes a first pane 202 and a second pane 204. The first pane 202 is or includes the glass sheet 10. The first pane 202 can be a laminate 203 where a first sheet 205 and the glass sheet 10 are laminated together with a polymer layer 207 therebetween. The first sheet 205 presents a first primary surface 209 of the first pane 202.

[0066] The second pane 204 can also be or include the glass sheet 10 but need not. A space 206 separates the first pane 202 and the second pane 204. In embodiments, the first pane 202 faces the external environment 110.

[0067] The architectural window 200 may be integral with an opening between the external environment 110 and the interior of an enclosure or building. Further, the architectural window 200 may be part of a door system on an enclosure or building. In embodiments, the architectural window 200 is movable with respect to an opening in a building. The architectural window 200 may be a double pane (as illustrated) or a triple pane window. Of course, the architectural window 200 may include any number of glass panes.

[0068] The architectural window 200 may further include a spacer 208 between its panes, such as to define the space 206 separating the first pane 202 from the second pane 204. The spacer 208 may be an edge seal formed around respective edges of its glass panes (e.g., the first pane 202 and the second pane 204), a metallic pillar between the surfaces of its glass panes, a low thermal conduction material, or a glass bump attached to or formed integral with one or bothAttorney Docket No. SP24-286PCT glass panes (e.g., the first pane 202 and the second pane 204). The space 206 is further defined at least in part by a distance 210 between the first pane 202 and the second pane 204. The distance 210 can be within a range of from 50 pm to about 50 mm, or within a range of from 5 mm to 25 mm. The space 206 may be sealed and include an insulating gas, such as air, argon, krypton, xenon, and combinations thereof. Alternatively, the space 206 may be sealed and include a pressure less than atmospheric pressure.

[0069] In embodiments, the architectural window 200 further includes a frame 212 surrounding perimeters of, and supporting, both the first pane 202 and the second pane 204. In embodiments, the frame 212 is configured to mate or communicate with an opening in a building or enclosure such that architectural window 200 is installed with either the first pane 202 or the second pane 204 adjacent the building interior and the other adjacent the building exterior. In embodiments, the frame 212 includes an overhanging edge portion configured to interfere with an edge of an opening in a building or enclosure and to prevent the architectural window 200 from being installed in the opening such that the one of the first pane 202 or the second pane 204 is adjacent the building interior. The architectural window 200 may also include a locking mechanism adjacent the one of the first pane 202 or the second pane 204 and internal to the building or enclosure. In embodiments, the locking mechanism is configured to be accessible only from the building interior, so as to limit access through the architectural window 200. In embodiments, the locking mechanism is fixed directly or indirectly to frame 212 and communicates with a portion of the opening in the building or enclosure.

[0070] Referring now to FIG. 8, a method 300 of making the glass sheet 10 is herein described. The method 300 includes a delivery step 302, a formation step 304, and a separation step 306. The delivery step 302 includes delivering the glass composition in molten form 308 to a mold 310. For example, batch materials 312 can be delivered to a furnace 314 to form the glass composition in molten form 308.

[0071] The formation step 304 includes molding the glass composition into a glass ribbon 316. For example, a slot draw technique can be utilized. For the slot draw technique, the glass composition in molten form 308 is delivered to a drawing tank 318, which operates as the mold 310. The drawing tank 318 (mold 310) has a bottom 320 and an open slot 322 at the bottom 320 with a nozzle that extends the length of the slot. The glass composition in molten form 308 flows through the slot / nozzle 322 and is drawn downward continuously as the glass ribbon 316. Techniques other than slot draw can be utilized, which are known in the art, such as fusion draw, where a weir operates as a mold 310, and roller formation.Attorney Docket No. SP24-286PCT

[0072] The separation step 306 includes separating the glass sheet 10 from the glass ribbon 316. As the glass ribbon 316 moves downward from the slot / nozzle, a separation device 324 known in the art (e.g., score and break, laser) creates a defect in the glass ribbon 316 where the glass sheet 10 can be separated therefrom. Many glass sheets 10 can be separated in sequence from the glass ribbon 316.

[0073] In embodiments, the primary crystalline phase 24 is present within the glass phase 22 before the separation step 306 occurs. As mentioned above, in embodiments of the glass composition, the primary crystalline phase 24 crystallizes as the molten glass cools during the formation step 304 or shortly thereafter. The molten glass has a sufficiently low viscosity overall to permit the glass composition to flow during the formation step 304. However, at that viscosity, the temperature of the glass composition is, in some instances, sufficiently low for the primary crystalline phase 24 to precipitate. Stated another way, the primary crystalline phase 24 has a liquidus viscosity that is less than the viscosity of the molten glass upon delivery to the mold 310 during the delivery step 302 or during the formation step 304. Consequently, the glass sheet 10 may not require a separate thermal treatment to cause the primary crystalline phase 24 to form after the separation step 306. That is advantageous, because the separate thermal treatment requires time and expends resources.

[0074] However, in embodiments, the method 300 further includes a heat treatment step 326. The heat treatment step 326 occurs after the formation step 304. The heat treatment step 326 causes the primary crystalline phase 24 to form within the glass phase 22. Before the heat treatment step 326, the glass ribbon 316 or the glass sheet 10 can be substantially free of the primary crystalline phase 24. In other instances, before the heat treatment step 326, the primary crystalline phase 24 can be present within the glass ribbon 316 or the glass sheet 10 but not as much as desired. In such instances, the heat treatment step 326 increases the amount of the primary crystalline phase 24 present in the glass ribbon 316 or the glass sheet 10. The heat treatment step 326 can occur with the glass ribbon 316 before the separation step 306. Instead of, or in addition to, the heat treatment step 326 can occur with the glass sheet 10 after the separation step 306.

[0075] The glass sheet 10 and the method 300 of the present disclose address the problem set forth in the Background, among other problems, in a variety of ways. Among them, the cerium atoms are largely in the primary crystalline phase 24, which forces a majority of the cerium to take a +3 oxidation state. Cerium in the +3 oxidation state blocks transmission of ultraviolet light much more effectively than cerium in other oxidation states (e.g., 0 or +4 oxidation states). If the glass sheet 10 did not include the primary crystalline phase 24, then the cerium withinAttorney Docket No. SP24-286PCT the glass sheet 10 would predominately take the +4 oxidation state, although some +3 oxidation states may be present. The glass sheet 10 of the present disclosure including the primary crystalline phase 24 thus blocks transmission of relevant wavelengths of ultraviolet light more than a similar glass sheet 10 without the primary crystalline phase 24. To sufficiently block transmission of ultraviolet light, as well as the glass sheet 10 of the present disclosure, much more cerium would need to be added to the glass composition, which increases expense. Similarly, the cerium forced to be in the 3+ oxidation state allows the sheet thickness 20 to be reduced compared to if the cerium were allowed to exist in both the 4+ and 3+ oxidation states and still exhibit the same reduction in transmission at desired ultraviolet wavelengths through the glass sheet 10. That attribute lowers the cost to manufacture and the weight of the glass sheet 10. The improved lack of transmission of ultraviolet light lengthens the serviceable life of satellites that include the glass sheet 10 as part of the photovoltaic module 100 generating electricity for the satellite.

[0076] In addition, the glass sheet 10 of the present disclosure can be formed on existing production equipment, such as the slot draw forming apparatus mentioned above. Otherwise, obsolete production equipment need not be utilized.

[0077] EXAMPLES 1-23

[0078] For Examples 1-23, glasses containing Ce were formed. The glasses were then analyzed to determine the mole percentages of the various constituents, and then tested to determine various properties that each glass substrate exhibits. The compositions and properties for each of the examples are set forth in Table 1 below.Table 1Example 1 2 3 4 5 6 analyzed mol%SiO₂ 75.48 76.13 75.44 74.19 74.87 74.554.91 4.96 4.93 4.89 4.94 4.95 MgO 2.86 2.63 2.69 3.01 2.7 2.7 CaO 3.26 3.06 3.14 3.45 3.1 3.09 Na2O 11.85 11.59 11.64 11.82 11.75 11.54 K2O 0.01 0.01 0.01 0.01 0.01 0.01 TiO₂ 0.47 0.96 0.96 0.96 1.46 1.46 CeO21.01 0.51 1.02 1.51 1.02 1.54 SnO₂ 0.16 0.16 0.16 0.16 0.16 0.17 Sum 100 100 100 100 100 100PropertiesDensity (g / cm3) 2.463 2.441 2.468 2.5 2.477 2.5 CTE (0-300 °C) ppm7.12 6.98 7.07 7.21 7.13 7.04(fiber)Attorney Docket No. SP24-286PCT Stain Point557 557 562 563 564 569 (fiber Elongation)Annealing Point605 604 609 610 610 616 (fiber Elongation)Softening Point825.6 826.4 828.7 823.5 823.5 828.8 (fiber Elongation)VET parameters fromHTVA -2.638 -1.76 -2.049 -1.876 -1.901 -1.835 B 7821.1 5519.7 6234.1 5651.4 5886 5626.9 To 37.4 215.4 162.5 216.8 187.4 223.2 isokom Temperature (°C)200 P 1621 1575 1596 1570 1588 1584 35000 P 1126 1091 1108 1097 1101 1105 120000 P 1051 1022 1037 1029 1031 1037 200000 P 1023 997 1011 1004 1005 1012 Liquidus (gradient boat)24 hoursAir (°C) 1045 1160 1235 1145 1270 1245 internal (°C) 1025 1015 1050 1015 1055 1140 Pt (°C) 1005 1000 1040 1015 1060 1135 primary phase Aeschynite Aeschynite Aeschynite Aeschynite Aeschynite Aeschynite 50 pm thick 50% cutoff345wavelength (nm)Table 1 - continuedExample 7 8 9 10 11 12 analyzed mol%SiO₂ 74.29 73.25 75.08 74.76 74.69 74.464.94 4.87 4.98 4.94 4.98 4.96 MgO 2.77 2.94 2.71 2.79 2.74 2.72 CaO 3.18 3.37 3.06 3.12 3.09 3.07 ZnO 0 0 0 0 0 0 Na2O 11.69 11.96 11.63 11.73 11.68 11.64 K2O 0.01 0.01 0.01 0.01 0.01 0.01 TiO21.94 1.93 1.93 1.93 1.93 2.41 CeO21.02 1.52 0.49 0.6 0.75 0.61 SnO20.16 0.16 0.12 0.14 0.15 0.12 Sum 100 100 100 100 100 100 PropertiesDensity (g / cm3) 2.486 2.517 2.459 2.465 2.473 2.473 CTE (0-300 °C) ppm7.18 7.28 6.99 7.09 7.07 7.08 (fiber)Stain Point (fiber566 565 550 548 550 554 Elongation)Annealing Point (fiber611 610 596 594 597 599 Elongation)Softening Point (fiber821.4 815.7 813.5 809.3 815.7 810.6 Elongation)Young's modulus72.6 73 73.1 73.3(GPa)Attorney Docket No. SP24-286PCT Shear modulus (GPa) 30.5 30.4 30.5 30.5 Poisson’s ratio 0.19 0.2 0.203 0.202 RI @ 589.3 nm 1.5134 1.5145 1.5152 1.5177 VFT parameters fromHTVA -1.903 -- -1.965 - -- -- B 5697.5 -- 6131.2 - -- -- To 205 -- 154.3 - -- -- isokom Temperature(°C)200 P 1560 -- 1592 - -- -- 35000 P 1089 -- 1096 - -- -- 120000 P 1021 -- 1025 - -- -- 200000 P 996 - 998 — - - Liquidus (gradientboat) 24 hoursAir (°C) 1275 1175 955 1040 1105 1060 internal (°C) 1060 1070 945 1000 1025 1020 Pt (°C) 1060 1065 925 995 1030 1020 primary phase Aeschynite Aeschynite Aeschynite Aeschynite Aeschynite Aeschynite Rutile or Rutile or Rutile or Rutile or secondary phaseDiopside Diopside Diopside Diopside 50 pm thick 50%cutoff wavelength 335 337 340 338(nm)Table 1 - continuedExample 13 14 15 16 17 18 analyzed mol%SiO₂ 74.38 76.13 77.19 75.73 76.3 76.17 Al2O34.94 5.03 5.12 5.48 5.98 5.05 MgO 2.78 2.45 2.27 2.43 2.27 2.44 CaO 3.12 2.84 2.65 2.84 2.64 1.83 ZnO 0 0.04 0.04 0.03 0.03 1.01 Na2O 11.46 10.89 10.12 10.88 10.16 10.89 K2O 0.01 0.01 0.01 0.01 0.01 0.01 TiO22.42 1.96 1.96 1.96 1.97 1.96 CeO20.76 0.49 0.49 0.49 0.5 0.49 SnO20.12 0.16 0.15 0.15 0.15 0.16 Sum 100 100 100 100 100 100 PropertiesDensity (g / cm3) 2.473 2.448 2.437 2.45 2.44 2.456 CTE (0-300 °C) ppm7.06 6.75 6.38 6.73 6.42 6.67 (fiber)Stain Point (fiber555 560 569 565 580 561 Elongation)Annealing Point (fiber601 608 617 612 628 608 Elongation)Softening Point (fiber812.4 832.7 850.8 838 866.1 836.8Elongation)Attorney Docket No. SP24-286PCT Young's modulus73.6(GPa)Shear modulus (GPa) 30.6Poisson’s ratio 0.202RI @ 589.3 nm 1.5186VFT parameters fromHTVA — -2.025 -1.927 -2.132 -2.484 -2.062 B — 6432.7 6397.1 6716.7 7759 6594.5 To — 146.8 168.9 134.6 72.9 136.9 isokom Temperature(°C)200 P — 1634 1682 1650 1694 1648 35000 P — 1126 1157 1141 1177 1135 120000 P — 1052 1082 1066 1099 1060 200000 P — 1025 1054 1038 1070 1033 Liquidus (gradientboat) 24 hoursAir (°C) 1080 1010 1015 1045 1060 1010 internal (°C) 1020 1000 1000 995 1035 995 Pt (°C) 1015 985 970 980 1045 990 primary phase Aeschynite Aeschynite Aeschynite Aeschynite Aeschynite Aeschynite Rutile or Rutile or Rutile or Rutile orsecondary phaseDiopside Diopside Diopside Diopside50 pm thick 50%cutoff wavelength 341(nm)Table 1 - continuedExample 19 20 21 22 23 analyzed mol%SiO₂ 75.85 74.82 74.08 73.56 74.36 Al2O35.49 6.91 7.35 7.36 6.88 MgO 2.4 2.5 2.54 2.56 2.51 CaO 1.82 2.29 2.19 2.2 2.31 ZnO 1 0 0 0 0 Na2<3 10.81 7.53 8.1 8.07 7.53 K2O 0.01 3.34 3.13 3.13 3.29 TiO21.97 1.98 1.97 2.47 2.47 CeO20.49 0.49 0.49 0.5 0.5 SnO20.15 0.15 0.15 0.15 0.16 Sum 100 100 100 100 100 PropertiesDensity (g / cm3) 2.457 2.446 2.45 2.457 2.453 CTE (0-300 °C) ppm (fiber) 6.69 7.15 7.25 7.36 7.18 Stain Point (fiber Elongation) 563 579 575 578 593 Annealing Point (fiber Elongation) 611 629 625 627 641 Softening Point (fiber Elongation) 844.6 876.4 875.7 870.8 884.2 Young's modulus (GPa) 72.6Shear modulus (GPa) 30.4Attorney Docket No. SP24-286PCT Poisson’s ratio 0.194 RI @ 589.3 nm 1.5137 VFT parameters from HTVA -2.123 -2.894 -2.516 -2.561 -2.642 B 6754.6 8800.8 7757.3 7844 8070.8 To 139.6 18.5 92.3 83.5 82.7 isokom Temperature (°C)200 P 1666 1713 1703 1697 1715 35000 P 1153 1202 1191 1188 1206 120000 P 1077 1122 1114 1110 1128 200000 P 1049 1092 1085 1081 1099 Liquidus (gradient boat) 24 hoursAir (°C) 995 1085 1175 1130 1120 internal (°C) 1030 1055 1055 1055 1080 Pt (°C) 1025 1060 1055 1065 1065 primary phase Aeschynite Aeschynite Aeschynite Aeschynite Aeschynitesecondary phase Rutile or Diopside Diopside Diopside Diopside Diopside

[0079] In the Table 1 above, the following properties were determined in the following ways. The density was determined using the buoyancy method of ASTM C693-93(2013). “CTE” refers to the coefficient of thermal expansion. The CTE can be characterized by methods known to those in the art, such as those described in ASTM E228 (and its progeny, all herein incorporated by reference) “Standard Test Method for Linear Thermal Expansion of Solid Materials with a Push-Rod Dilatometer.” The strain point temperature is determined using the beam bending viscosity method of ASTM C598-93 (2013). The annealing point is determined using the beam bending viscosity method of ASTM C598-93 (2013). The softening point temperature was determined using the parallel plate viscosity method of ASTM C1351M-96 (2012). The Young’s modulus, shear modulus, and Poisson’s ratio values recited in this disclosure refer to values as measured by a resonant ultrasonic spectroscopy technique of the general type set forth in ASTM E2001-13, titled “Standard Guide for Resonant Ultrasound Spectroscopy for Defect Detection in Both Metallic and Non-metallic Parts.” “RI” refers to the index of refraction. The index of refraction measurements were performed at the sodium D wavelength (589.3 nm) using a Bausch & Lomb Low Range Precision Refractometer with a sodium arc lamp. The Bausch & Lomb Precision Refractometer measures the refractive index of a material by measuring the critical angle. “VFT” refers to the Vogel-Fulcher-Tamman (VFT) equation: Log η=A+B / (T₀-C), where To is the temperature, A, B and C are fitting constants and r| is the dynamic viscosity. Isokom temperature is the temperature at which the composition had the stated viscosity (e.g., 200 P, 35000 P, 120000 P, or 200000 P).Attorney Docket No. SP24-286PCT

[0080] “Liquidus” refers to the liquidus temperature of the glass as measured using the standard gradient boat liquidus method of ASTM C829-81. This involves placing crushed glass particles in a platinum boat, placing the boat in a furnace having a region of gradient temperatures, heating the boat in an appropriate temperature region for 24 hours, and determining by means of microscopic examination the highest temperature at which crystals appear in the interior of the glass. More particularly, the glass sample is removed from the Pt boat in one piece, and examined using polarized light microscopy to identify the location and nature of crystals which have formed against the Pt (“Pt”) and air (“air”) interfaces, and in the interior of the sample (“internal”). Because the gradient of the furnace is very well known, temperature vs. location can be well estimated, within 5-10° C. The temperature at which crystals are observed in the internal portion of the sample is taken to represent the liquidus temperature of the glass (for the corresponding test period). “Primary phase” and “secondary phase” refer to the crystalline phase(s) that developed during the liquidus testing. Particular phase names are determined by one or more of crystal shape, birefringence (a, b, c symmetry), and X-ray diffraction.

[0081] “ 50 pm thick 50% cutoff wavelength” refers to the wavelength below which 50% or less of electromagnetic radiation incident upon the glass sheet (having a thickness of 50 pm) is transmitted through the glass sheet. Transmission spectrum is obtained in accordance with ASTM D1003 but with replacing the class C light source with a light source that produces the solar spectrum (i.e., the AM 1.5 G spectrum).

[0082] All of the Examples demonstrated crystallization of aeschynite during the liquidus testing. Therefore, all of the as analyzed glass compositions are capable of forming aeschynite as the primary crystalline phase upon subsequent heat treatment.

[0083] Regarding the “50 pm thick 50% cutoff wavelength,” that data was obtained with the glass sheet having the glass composition only - that is, without the presence of the aeschynite crystalline phase. It is believed that if the glass sheets had been heat treated to form the aeschynite primary crystalline phase before testing for the 50% cutoff wavelength, the 50% cutoff wavelength would have been a wavelength longer than the reported value. That is because the heat treatment would have forced much of the cerium therein to take the +3 oxidation state as part of the aeschynite crystalline phase. The 50% cutoff wavelength being longer and moving closer to 400 nm is beneficial for reducing transmission of ultraviolet wavelengths that degrade the photovoltaic cells.

[0084] The compositions of the Examples were as analyzed after the glass sheet was formed. As formed, none of the glass sheets of the Examples included an aeschynite crystalline phaseAttorney Docket No. SP24-286PCT (or any other crystalline phase). However, it is believed that if the glass sheets of the Examples did include the aeschynite crystalline phase upon formation or after a subsequent heat treatment, then the as analyzed compositions would have substantially the same as those provided in Table 1, especially if only the glass phase was analyzed. Further, the formation of the aeschynite crystalline phase during the liquidus testing demonstrates that each glass sheet of the Examples was capable of forming the aeschynite crystalline phase upon a heat treatment after formation of the glass sheet.

[0085] Examples 3 and 5-7 are notable because the liquidus temperature as measured (internal) was greater than the (isokom) temperature at which the glass exhibited a viscosity of 120,000 P. As mentioned above, the glass is delivered during a delivery step to the mold (e.g., slot draw) at the temperature where the glass has a viscosity of 120,000 P. When the liquidus temperature is greater than the temperature of the delivery step, then the primary crystalline phase will precipitate during the formation step. In other words, the primary crystalline phase (particularly aeschynite for the Examples) will be present in the glass ribbon. Glass sheets separated from the glass ribbon will also include the primary crystalline phase. Thus, a heat treatment step after the separation step would be unnecessary to force the crystallization to occur. One further observation is that the as analyzed compositions for each of Examples 3 and 5-7 included at least 1 mole percent of CeO2. It may be that the higher the mole percent of CeO2, the greater the likelihood that the aeschynite primary crystalline phase will be present upon formation.

[0086] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the claims.

Claims

Attorney Docket No. SP24-286PCT CLAIM(S)What is claimed is:

1. A glass sheet comprising:a glass phase comprising a glass composition; anda primary crystalline phase dispersed within the glass phase, the primary crystalline phase comprising cerium atoms, a majority of which have a +3 oxidation state.

2. The glass sheet of claim 1 further comprising:a sheet thickness within a range of from 40 pm to 200 pm.

3. The glass sheet of any one of claims 1-2, whereinthe glass composition comprises (in mol%, on an oxide basis):from 73.0 to 78.0 SiO2;from 4.00 to 8.00 Al2O3;from 2.00 to 3.50 MgO;from 1.50 to 4.00 CaO;from 7.00 to 12.50 Na2O;from 0.20 to 3.00 TiO2; andfrom 0.20 to 2.00 CeO2.

4. The glass sheet of claim 3, whereinthe glass composition comprises from 0.59 to 2.00 CeO2.

5. The glass sheet of any one of claims 3-4, whereinthe glass composition comprises from >0 to 1.50 ZnO.

6. The glass sheet of any one of claims 3-5, whereinthe glass composition comprises from >0 to 4.00 K2O.

7. The glass sheet of any one of claims 3-6, whereinthe glass composition comprises from >0 to 0.50 SnO2.

8. The glass sheet of any one of claims 1-7, whereinthe primary crystalline phase is aeschynite.Attorney Docket No. SP24-286PCT9. The glass sheet of any one of claims 1-8, whereinthe primary crystalline phase further comprises atoms of calcium, titanium, and oxygen.

10. The glass sheet of any one of claims 1-9 further comprising:a secondary crystalline phase dispersed within the glass phase,wherein, the secondary crystalline phase comprises one or more of rutile and diopside.

11. The glass sheet of any one of claims 1-10, whereinthe glass sheet exhibits a density within a range of from 2.430 g / cm3to 2.550 g / cm3.

12. The glass sheet of any one of claims 1-11, whereinthe glass sheet exhibits a coefficient of thermal expansion within a range of from 6.20 ppm / °C to 7.50 ppm / °C.

13. The glass sheet of any one of claims 1-12, whereinthe glass sheet exhibits an internal liquidus temperature that is greater than a temperature at which the glass sheet exhibits a viscosity of 120,000 Poise.

14. A photovoltaic module comprising:one or more photovoltaic cells; anda cover sheet comprising the glass sheet of claim 1 disposed between the one or more photovoltaic cells and an external environment.

15. The photovoltaic module of claim 14 further comprising:an encapsulant at least partially encapsulating the one or more photovoltaic cells.

16. An architectural window comprising:a first pane comprising the glass sheet of claim 1; anda second pane separated from the first pane by a space.

17. The architectural window of claim 16 further comprising:a frame surrounding perimeters of both the first pane and the second pane.Attorney Docket No. SP24-286PCT 18. A method of making a glass sheet, the method comprising:a delivery step comprising delivering a glass composition in molten form to a mold, the glass composition comprising cerium atoms;a formation step comprising molding the glass composition into a glass ribbon; and a separation step comprising separating a glass sheet from the glass ribbon, wherein, the glass sheet comprises: (a) a glass phase comprising a glass composition; and (b) a primary crystalline phase dispersed within the glass phase, the primary crystalline phase comprising cerium atoms, a majority of which have a +3 oxidation state.

19. The method of claim 18, whereinthe primary crystalline phase is present within the glass phase before the separation step occurs.

20. The method of any one of claims 18-19, whereinthe primary crystalline phase is formed during the formation step.

21. The method of claim 18 further comprising:a heat treatment step occurring after the formation step to cause the primary crystalline phase to form within the glass phase.

22. The method of claim 21, whereinthe heat treatment step occurs before the separation step.

23. The method of claim 21, whereinthe heat treatment step occurs after the separation step.

24. The method of any one of claims 18-23, whereinthe glass composition comprises (in mol%, on an oxide basis):from 73.0 to 78.0 SiO2;from 4.00 to 8.00 Al2O3;from 2.00 to 3.50 MgO;from 1.50 to 4.00 CaO;Attorney Docket No. SP24-286PCTfrom 7.00 to 12.50 Na2O; from 0.20 to 3.00 TiO2; and from 0.20 to 2.00 CeO2.

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