Borate light extraction region

Abstract

To provide a substrate having increased light scattering for improved light utilization.SOLUTION: The invention relates to a light extraction substrate (10) having a light extraction layer (16). The light extraction layer (16) includes boron, borate, and / or borosilicate as well as nanoparticles (18).SELECTED DRAWING: Figure 1a

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority to U.S. Patent Application No. 16 / 295,566, filed on March 7, 2019, the disclosure of which is hereby incorporated by reference in its entirety.

[0002] (Technical Field) The present invention relates to forming a borosilicate layer inside or on a substrate (e.g., glass or glass ribbon), and optionally embedding nanoparticles within the borosilicate layer. The present invention also relates to organic light - emitting diodes, solar cells or photovoltaic (PV) cells, and daylighting windows, and more specifically, to substrates having increased light scattering to improve light utilization.

Background Art

[0003] An organic light - emitting diode (「OLED」) is a light - emitting device having a light - emitting electroluminescent layer containing an organic compound. The organic compound emits light in response to an electric current. Typically, the light - emitting layer of an organic semiconductor material is disposed between two electrodes (an anode and a cathode). When an electric current flows between the anode and the cathode, the organic material emits light. OLEDs are used in many applications such as television screens, computer monitors, mobile phones, PDAs, watches, lighting, and various other electronic devices.

[0004] OLEDs offer several advantages over conventional inorganic devices such as liquid - crystal displays. For example, OLEDs function without the need for a backlight. In low ambient light conditions such as in a dark room, an OLED screen can achieve a higher contrast ratio than a conventional liquid - crystal display. OLEDs are thinner, lighter, and more flexible than liquid - crystal displays and other lighting devices.

[0005] When fabricating an OLED, typically, a light extraction region in which nanoparticles are partially or fully embedded is added. For example, the nanoparticles may be embedded within the substrate. If the substrate is glass, the nanoparticles must be embedded while the substrate is at a temperature exceeding 725°C, typically while at a temperature exceeding 800°C. There is a need to embed the nanoparticles within the glass substrate when the glass ribbon is at a lower temperature (such as 725°C or less). SUMMARY OF THE INVENTION

[0006] The present invention relates to a light extraction substrate. The substrate includes glass. The glass has a first surface and a second surface opposite the first surface. A light extraction layer is disposed on the first surface. The light extraction layer includes borosilicate. The light extraction layer may or may not include nanoparticles. The light extraction substrate may further include an external light extraction layer on or over the second surface of the substrate. The internal light extraction layer may be part of the substrate or a separate layer on the substrate.

[0007] In another embodiment, the present invention relates to an organic light emitting diode (「OLED」). The OLED includes a substrate having a first surface and a second surface. The second surface is opposite the first surface. A light extraction layer is disposed on the first surface of the substrate. The light extraction layer includes a borosilicate layer. A transparent conductive oxide layer is disposed on at least a portion of the light extraction layer. A light emitting layer is disposed on at least a portion of the transparent conductive oxide layer. A cathode layer is disposed on at least a portion of the light emitting layer.

[0008] Another embodiment of the present invention relates to a method of fabricating a light extraction substrate. The method includes pouring a glass melt onto a molten metal bath. A boron precursor is applied onto the glass melt while the temperature of the glass melt is at least 600°C and does not exceed 725°C.

[0009] Another embodiment of the present invention relates to a method of fabricating a light extraction substrate. The method includes pouring a glass melt onto a molten metal bath. The glass melt contains silicon. While the temperature of the glass melt is at least 600°C and does not exceed 725°C, a boron precursor is applied onto the glass melt. Silicon within the glass melt reacts with the boron precursor to form borosilicate on the glass melt.

[0010] Another embodiment of the present invention relates to a method of fabricating a light extraction substrate. The method includes pouring a glass melt onto a molten metal bath. The glass melt contains silicon. While the temperature of the glass melt is less than 725°C, a boron precursor is applied onto the glass melt. A silicon precursor is applied onto the glass melt having a temperature less than 725°C. The silicon precursor and the boron precursor form borosilicate on or within the glass melt.

Brief Description of the Drawings

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BEST MODE FOR CARRYING OUT THE INVENTION

[0019] As used herein, spatial or directional terms such as "left", "right", "inner", "outer", "upper", "lower", etc. are in relation to the present invention as shown in the drawings. However, it should be understood that the present invention can take various alternative orientations, and thus such terms should not be considered limiting. Further, as used herein, all numbers representing dimensions, physical properties, processing parameters, amounts of components, reaction conditions, etc. used in this specification and the claims are to be understood to be modified in all instances by the term "about". Thus, unless indicated to the contrary, the numerical values set forth in the following specification and claims are subject to change depending upon the desired properties sought to be obtained by the present invention. At a minimum, rather than as an attempt to limit the scope of the claims to the application of the doctrine of equivalents, each numerical value should be construed in light of the reported significant digits and by applying ordinary rounding techniques. Further, all ranges disclosed herein are to be understood to encompass the starting and ending range values, as well as all subranges subsumed therein. For example, a specified range of "1 to 10 (1~10)" should be considered to include all subranges between (and including) the minimum value of 1 and the maximum value of 10, i.e., all subranges that begin with a minimum value of 1 or more and end with a maximum value of 10 or less (such as 1~3.3, 4.7~7.5, 5.5~10, etc.). Further, all documents referred to herein (including, but not limited to, issued patents and patent applications) are to be considered incorporated by reference in their entirety. References to amounts are, unless otherwise specified, "weight percent".

[0020] When referring to a layer of a coating, the term "over" means "farther from the substrate surface". For example, a second layer located "over" a first layer means that the second layer is located farther from the substrate surface on which they are present than the first layer. The second layer can be in direct contact with the first layer, or one or more other layers can be disposed between the second layer and the first layer.

[0021] All documents referred to in this specification should be considered to be incorporated herein by reference in their entirety.

[0022] References to amounts are, unless otherwise specified, "weight percent".

[0023] The term "film" means an area having a desired or selected composition. A "layer" includes one or more "films". A "coating" is composed of one or more "layers". The term "organic material" includes polymers and small molecule organic materials that can be used to manufacture organic optoelectronic devices.

[0024] The term "visible light" means electromagnetic radiation having wavelengths in the range of 380 nm to 780 nm. The term "infrared" means electromagnetic radiation having wavelengths in the range greater than 780 nm to 100,000 nm. The term "ultraviolet" means electromagnetic energy having wavelengths in the range of 100 nm to less than 380 nm.

[0025] The terms "metal" and "metal oxide" include silicon and silica, as well as traditionally recognized metals and metal oxides, even when silicon has not traditionally been considered a metal. The term "curable" means a composition that can polymerize or crosslink. "Cured" means that the material is at least partially polymerized or crosslinked, preferably completely polymerized or crosslinked. "At least" means "greater than or equal to". "Not more than" means "less than or equal to". The terms "upstream" and "downstream" refer to the direction of travel of the glass ribbon.

[0026] The haze and transmittance values in this specification were determined using a Haze-Gard Plus haze meter (commercially available from BYK-Gardner USA) or a Perkin Elmer Lambda 9 spectrophotometer. The surface roughness values were determined using an Instrument Dimension 3100 atomic force microscope.

[0027] The description of the present invention can describe certain features as being “in particular” or “preferably” within certain limits (for example, “preferably,” “more preferably,” “even more preferably,” or “most preferably” within certain limits). It should be understood that the present invention is not limited to these specific or preferred limits and encompasses the entire scope of the present disclosure.

[0028] The present invention includes, consists of, or consists essentially of the following aspects of the present invention in any combination. The various aspects of the present invention are shown in separate drawings. However, it should be understood that this is merely for the purpose of facilitating illustration and explanation. In the practice of the present invention, one or more aspects of the present invention shown in one drawing can be combined with one or more aspects of the present invention shown in one or more other drawings.

[0029] The present invention relates to a substrate comprising a light extraction layer 16 containing nanoparticles 18 embedded therein. As shown in FIG. 1, a substrate 10 is provided. The substrate 10 can have a high visible light transmittance. “High visible light transmittance” means a visible light transmittance of at least 85%, for example at least 87%, at a reference wavelength of 550 nanometers (nm) and a reference thickness of 2 mm. For example, at least 90% or the like. For example, at least 91% or the like. For example, at least 92% or the like. For example, at least 93% or the like. The substrate 10 having the light extraction layer 16 and the nanoparticles 18 can have a haze of at least 20%, preferably at least 30%, more preferably at least 35%, and most preferably at least 37%.

[0030] The substrate 10 may be glass. For example, the substrate 10 can be low-iron glass. "Low-iron" means that the total iron content is less than 400 parts per million (ppm), for example, less than 350 ppm. For example, the total iron content can be less than 300 ppm. For example, the total iron content can be less than 200 ppm. Examples of materials suitable for the substrate 10 include soda-lime silicate glass, such as float glass. The substrate 10 may be a glass ribbon. A glass ribbon is hot glass floating on a metal bath (such as a tin bath) and is gradually cooled while floating on the metal bath. The glass ribbon is gradually cooled from about 1100 °C to about 600 °C on the metal bath.

[0031] The substrate 10 can have any desired thickness. For example, the thickness of the substrate 10 can be in the range of 0.5 mm to 10 mm, for example, 1 mm to 10 mm, for example, 1 mm to 4 mm. For example, the thickness of the substrate 10 can be in the range of 2 mm to 3.2 mm.

[0032] The substrate 10 has a first surface 12 and a second surface 14. The second surface 14 is on the opposite side of the first surface 12.

[0033] As shown in FIG. 1A, the light extraction layer 16 is disposed on at least a part of the first surface 12 or is partially embedded in the substrate 10. The light extraction layer 16 contains borosilicate. Borosilicate is a glass containing silica (SiO2) and boron trioxide (B2O3). The light extraction layer 16 containing the nanoparticles 18 is generally smooth and can have an average surface roughness of less than 5 nm.

[0034] The light extraction layer 16 can be formed on the first surface 12 of the substrate 10 according to the following method. The substrate 10 may be glass. The substrate 10 is provided at a temperature of 650 °C or lower, preferably 630 °C or lower, more preferably 620 °C or lower, and most preferably 610 °C or lower, and / or at a temperature of at least 400 °C, preferably at least 500 °C, more preferably at least 525 °C, and most preferably at least 550 °C. For example, the temperature of the substrate 10 may be about 600 °C. The light extraction layer 16 is applied by applying a boron precursor that forms borosilicate. The boron precursor can be trimethyl borate, triethyl borate, phenylboron dichloride, boron bromide, or boron fluoride. In one non-limiting embodiment, the boron precursor is trimethyl borate. When the boron precursor is applied to the substrate 10 within the temperature range described in this paragraph, silicon can diffuse from the glass substrate 10 and react with boron species to form borosilicate. If the temperature is less than 400 °C, the boron precursor is less likely to form B2O3.

[0035] If the temperature exceeds 650 °C, the light extraction layer 16 is likely to be (at least partially) formed within the substrate 10 (as shown in FIG. 1B). Accordingly, an alternative embodiment of the present invention is shown in FIG. 1B, where the light extraction layer 16 can be partially or entirely disposed inside or be an integral part of the substrate 10. In this embodiment, the light extraction layer 16 is disposed partially or entirely under the first surface 12 or entirely under the first surface, between the first surface 12 and the second surface 14.

[0036] The light extraction layer 16 can be formed on the first surface 12 of the substrate 10 in several ways. One way relates to embodiments where the substrate is glass, such as float glass or soda-lime glass. In this method, the glass melt is poured onto a metal bath to form a glass ribbon. A boron precursor is applied onto the glass ribbon. The boron precursor is applied when the temperature of the glass ribbon is 800 °C or lower, preferably 750 °C or lower, most preferably 730 °C or lower, most preferably 725 °C or lower, and 500 °C or higher, preferably 550 °C or higher, more preferably 575 °C or higher, most preferably 600 °C or higher. For example, the glass ribbon can be at a temperature of about 650 °C.

[0037] When the glass ribbon is at least 500 °C and a borosilicate is applied to the glass ribbon, a part of the silicon in the glass ribbon diffuses into the borate layer to form a borosilicate coating.

[0038] Alternatively, the boron precursor can be applied onto the substrate 10 when the substrate is below 500 °C, preferably below 300 °C, more preferably below 200 °C, most preferably below 100 °C. For example, the temperature of the substrate can be about 20 - 25 °C or can be at room temperature.

[0039] Optionally, the silicon precursor can be applied simultaneously and / or immediately after the boron precursor is applied to form a borosilicate. The silicon precursor can be tetraethyl orthosilicate, silicon acetate, silane, chlorosilane, methylchlorosilane, ethylchlorosilane, or silicon chloride. In one non-limiting example, the silicon precursor is tetraethyl orthosilicate.

[0040] For example, the silicon precursor can be supplied to the vaporizer simultaneously with the boron precursor being supplied to the vaporizer. The silicon precursor and the boron precursor are simultaneously vaporized by the vaporizer to form the vaporized boron and silicon precursors. The vaporized boron and silicon precursors can be supplied to a coater where the vaporized boron and silicon precursors are applied to the glass ribbon.

[0041] In another example, the silicon precursor can be supplied to a first vaporizer. The first vaporizer vaporizes the silicon precursor to form the vaporized silicon precursor. The vaporized silicon precursor is supplied to a coater, and the coater applies the vaporized silicon precursor to the glass ribbon. After the vaporized silicon precursor has been applied to the glass ribbon, the vaporized boron precursor is applied to the glass ribbon that includes the vaporized silicon precursor that has been vaporized and applied. The vaporized boron precursor is formed by supplying the boron precursor to a second vaporizer. The second vaporizer vaporizes the boron precursor. The vaporized boron precursor is supplied to a second coater. The second coater applies the vaporized boron precursor to the glass ribbon that includes the vaporized silicon precursor that has been vaporized and applied. When the vaporized silicon precursor and the vaporized boron precursor are applied, a borosilicate layer is formed. The borosilicate can be present on, embedded within, or an integral part of the glass ribbon depending on the temperature of the glass ribbon, where the upper portion of the glass ribbon includes the borosilicate layer.

[0042] In another example, a boron precursor can be supplied to a first vaporizer. The first vaporizer vaporizes the boron precursor to form a vaporized boron precursor. The vaporized boron precursor is supplied to a coater, and the coater applies the vaporized boron precursor to the glass ribbon. After the vaporized boron precursor is applied to the glass ribbon, a vaporized silicon precursor is applied to the glass ribbon containing the vaporized and applied boron precursor. The vaporized silicon precursor is formed by supplying a silicon precursor to a second vaporizer. The second vaporizer vaporizes the silicon precursor. The vaporized silicon precursor is supplied to a second coater. The second coater applies the vaporized silicon precursor to the glass ribbon containing the vaporized boron precursor that has been vaporized and applied. When the vaporized boron precursor and the vaporized silicon precursor are applied, a borosilicate layer is formed. The borosilicate can be present on, embedded within, or an integral part of the glass ribbon depending on the temperature of the glass ribbon, where the top portion of the glass ribbon includes the borosilicate layer.

[0043] In another example, a silicon precursor can be supplied to a first vaporizer. The first vaporizer vaporizes the silicon precursor to form a vaporized silicon precursor. The vaporized silicon precursor is supplied to a coater, and the coater applies the vaporized silicon precursor to a glass ribbon. After the vaporized silicon precursor is applied to the glass ribbon, a vaporized boron precursor and a second vaporized silicon precursor are applied to the glass ribbon containing the vaporized and applied silicon precursor. The vaporized boron precursor and the vaporized silicon precursor are formed by supplying the boron precursor and the silicon precursor to a second vaporizer. The second vaporizer vaporizes the boron precursor and the silicon precursor to form a vaporized boron precursor and a vaporized silicon precursor. The vaporized boron precursor and the vaporized silicon precursor are supplied to a second coater. The second coater applies the vaporized boron precursor and the vaporized silicon precursor to the glass ribbon containing the vaporized and applied silicon precursor. Thereby, a borosilicate layer is formed. The borosilicate can be present on, embedded within, or integral with the glass ribbon depending on the temperature of the glass ribbon, where the upper portion of the glass ribbon includes the borosilicate layer.

[0044] In another example, a silicon precursor and a boron precursor can be supplied to a first vaporizer. The first vaporizer vaporizes the silicon precursor and the boron precursor to form a vaporized silicon precursor and a vaporized boron precursor. The vaporized silicon precursor and the vaporized boron precursor are supplied to a coater, and the coater applies the vaporized silicon precursor and the vaporized boron precursor to a glass ribbon. After the vaporized silicon precursor and the vaporized boron precursor are applied to the glass ribbon, a vaporized silicon precursor is applied to the glass ribbon including the vaporized silicon precursor and the vaporized boron precursor that have been vaporized and applied. The vaporized silicon precursor is formed by supplying the silicon precursor to a second vaporizer. The second vaporizer vaporizes the silicon precursor. The vaporized silicon precursor is supplied to a second coater. The second coater applies the vaporized silicon precursor to the glass ribbon including the vaporized silicon precursor and the vaporized boron precursor that have been vaporized and applied. Thereby, a borosilicate layer is formed. The borosilicate can be present on, embedded within, or integral with the glass ribbon depending on the temperature of the glass ribbon, where the upper portion of the glass ribbon includes the borosilicate layer.

[0045] In another example, a silicon precursor can be supplied to a first vaporizer. The first vaporizer vaporizes the silicon precursor to form a vaporized silicon precursor. The vaporized silicon precursor is supplied to a coater, and the coater applies the vaporized silicon precursor to a glass ribbon. After the vaporized silicon precursor is applied to the glass ribbon, a vaporized boron precursor is applied to the glass ribbon that includes the vaporized and applied silicon precursor. The vaporized boron precursor is formed by supplying a boron precursor to a second vaporizer. The second vaporizer vaporizes the boron precursor. The vaporized boron precursor is supplied to a second coater. The second coater applies the vaporized boron precursor to the glass ribbon that includes the vaporized and applied silicon precursor. A second silicon precursor is vaporized and applied via a third vaporizer and a third coater in the same manner as the first silicon precursor is vaporized and applied, where the third vaporizer and the third coater are disposed downstream of the first vaporizer and the first coater and the second vaporizer and the second coater. Thereby, a borosilicate layer is formed. The borosilicate can be present on, embedded within, or integral with the glass ribbon depending on the temperature of the glass ribbon, where the top portion of the glass ribbon includes the borosilicate layer.

[0046] The light extraction layer can also be formed by the following alternative method. In this method, a glass melt is poured onto a metal bath to form a glass ribbon. A boron precursor is applied onto the glass ribbon. The boron precursor is applied to the glass ribbon when the temperature of the glass ribbon is 650 °C or lower, preferably 630 °C or lower, more preferably 620 °C or lower, most preferably 610 °C or lower, and / or when the temperature is at least 400 °C, preferably at least 500 °C, more preferably at least 525 °C, most preferably at least 550 °C. For example, the temperature may be about 600 °C. Optionally, a silicon precursor can be applied before, simultaneously with, or immediately after the boron precursor is applied to form borosilicate in the same manner as above. By this method, the light extraction layer 16 forms a separate borate layer or borosilicate layer applied on the first surface, but is integrated with the substrate 10 as if it were part of the substrate.

[0047] The light extraction layer 16 can have a thickness of at least 0.1 micron, preferably at least 0.25 micron, more preferably at least 0.4 micron, and most preferably at least 0.5 micron. The light extraction layer 16 can have a maximum thickness of 3 microns, preferably a maximum thickness of 2.75 microns, more preferably a maximum thickness of 2.5 microns, and most preferably a maximum thickness of 2.25 microns. In certain embodiments, the extraction layer 16 is disposed on the first surface 12 of the substrate, and the light extraction layer 16 can have a thickness of at least 0.1 micron, preferably at least 0.25 micron, more preferably at least 0.4 micron, and most preferably at least 0.5 micron, and can have a maximum thickness of 2 microns, preferably a maximum thickness of 1.75 microns, more preferably a maximum thickness of 1.5 microns, and most preferably a maximum thickness of 1.25 microns. In other embodiments, the light extraction layer 16 is embedded or partially embedded within the first surface 12 of the substrate 10, and the light extraction layer 16 can have a thickness of at least 0.5 micron, preferably at least 0.75 micron, more preferably at least 0.9 micron, and most preferably at least 1 micron, and can have a maximum thickness of 3 microns, preferably a maximum thickness of 2.75 microns, more preferably a maximum thickness of 2.5 microns, and most preferably a maximum thickness of 2.25 microns. -

[0048] Optionally, the nanoparticles 18 can be embedded in the light extraction layer 16. The nanoparticles can be a material having a refractive index higher than that of the substrate, i.e., a high refractive index material. For example, the nanoparticles 18 can be metal oxides. For example, the nanoparticles 18 can be alumina, titania, cerium oxide, zinc oxide, tin oxide, silica, zirconia, mixtures thereof, or alloys thereof. Other examples include metal nanoparticles. For example, but not limited to, iron, steel, copper, silver, gold, titanium, etc. Further examples include alloy nanoparticles containing alloys of two or more materials. For example, alloys of two or more of zinc, tin, gold, copper, and silver. In one particular embodiment, the nanoparticles contain titania.

[0049] The nanoparticles 18 can have a diameter of up to 50 nm, preferably up to 45 nm, more preferably up to 40 nm, and most preferably up to 35 nm. The nanoparticles 18 can have a diameter of at least 5 nm, preferably at least 10 nm, more preferably at least 15 nm, and most preferably at least 20 nm.

[0050] The nanoparticles 18 in the light extraction layer 16 can be present in the range of 0.1 weight percent to 50 weight percent, for example, 0.1 weight percent to 40 weight percent, for example, 0.1 weight percent to 30 weight percent, for example, 0.1 weight percent to 20 weight percent, for example, 0.1 weight percent to 10 weight percent, for example, 0.1 weight percent to 8 weight percent, for example, 0.1 weight percent to 6 weight percent, for example, 0.1 weight percent to 5 weight percent, for example, 0.1 to 2 weight percent, for example, 0.1 to 1 weight percent, for example, 0.1 to 0.5 weight percent, for example, 0.1 to 0.4 weight percent, for example, 0.1 to 0.3 weight percent, for example, 0.2 weight percent to 10 weight percent, for example, 0.2 weight percent to 5 weight percent, for example, 0.2 weight percent to 1 weight percent, for example, 0.2 weight percent to 0.8 weight percent, for example, 0.2 weight percent to 0.4 weight percent.

[0051] As shown in FIG. 2, in one embodiment, the article 1 may further include an external light extraction layer 22 disposed on the second surface 14 of the substrate 10. The external light extraction layer 22 can be formed by a coating such as a metal oxide coating having a roughened outer surface. Examples of oxides useful for the external light extraction layer 22 include silica, alumina, zinc oxide, titania, zirconia, tin oxide, and / or mixtures or alloys thereof. The external light extraction layer 22 can have an average surface roughness (Ra) in the range of 5 nm to 500 nm, for example, in the range of 25 nm to 500 nm, for example, in the range of 50 nm to 500 nm, for example, in the range of 50 nm to 200 nm, for example, in the range of 100 nm to 200 nm. The external light extraction layer 22 can have a root mean square roughness (Rq) in the range of 100 nm to 250 nm, for example, in the range of 150 nm to 200 nm. The external light extraction layer 22 can have a thickness in the range of 10 nm to 500 nm, for example, in the range of 50 nm to 500 nm, for example, in the range of 100 nm to 500 nm. The external light extraction layer 22 can be a single layer or an optionally multilayer coating.

[0052] The roughness of the external light extraction layer 22 can be formed by several techniques. One technique is to form a coating having a roughened outer surface. The coating can be a metal oxide such as silica, alumina, zinc oxide, titania, zirconia, tin oxide, or a mixture thereof. Alternatively, the external light extraction layer 22 can be formed by texturing the second surface 14 of the glass, such as by mechanically roughening the surface of the substrate, for example, by mechanical abrasion or chemical etching.

[0053] The light extraction layer 16 containing the nanoparticles 18 can be used in various applications. In one embodiment, as shown in FIGS. 3A and 3B, the article 1 is a privacy glazing. The article 1 has a substrate 10. The light extraction layer 16 is formed on at least a part of the first surface 12 of the substrate 10 or is embedded in the substrate 10 at the first surface 12. The light extraction layer 16 contains the nanoparticles 18 as described above. An optional coating 24 may be present. The optional coating 24 may be one or more layers as described below used in an OLED article. For example, the optional coating 24 may be an anode layer. Alternatively, the optional coating 24 can be a metal oxide, a metal nitride, a metal oxynitride, or a metal. For example, the optional coating 24 may be zinc oxide, zinc stannate, tin oxide, silicon nitride, titania, silica, alumina, silver, gold, copper, a mixture thereof, or an alloy thereof. The light source 26 is disposed adjacent to the edge 28 of the article 1. When the light source 26 is deactivated, the article 1 has a first transparency level. When the light source 26 is active, the nanoparticles 18 scatter the light wave 30 from the light source 26, and the article has a second transparency level. Due to the scattering of the light wave 30 by the nanoparticles 18, the second transparency level is lower than the first transparency level.

[0054] In another embodiment, the light extraction layer 16 can be used in an organic light emitting diode (「OLED」). Thus, the article 1 is an OLED. In this embodiment, as shown in FIGS. 4A and 4B, the OLED 1 includes a substrate 10, a light extraction layer 16 containing nanoparticles 18 on the first surface 12 of the substrate 10, an external light extraction layer 22 on the second surface 14 of the substrate 10, a cathode 32, a light emitting layer 34, and an anode 36.

[0055] The cathode 32 can be any conventional OLED cathode. Examples of suitable cathodes 32 include, but are not limited to, barium and calcium.

[0056] The light-emitting layer 34 can be a conventional organic electroluminescence layer known in the art. Examples of such materials include, but are not limited to, organometallic chelates (e.g., Alq3), fluorescent and phosphorescent dyes, and small molecules such as conjugated dendrimers. Examples of suitable materials include triphenylamine, perylene, rubrene, and quinacridone. Alternatively, electroluminescent polymer materials are also known. Examples of such conductive polymers include poly(p-phenylenevinylene) and polyfluorene. A phosphorescent material can also be used. Examples of such materials include polymers such as poly(n-vinylcarbazole) with an organometallic complex such as an iridium complex added as a dopant.

[0057] The anode 36 can be made of a conductive transparent material, for example, a metal oxide material, such as, but not limited to, indium tin oxide (ITO) or aluminum-doped zinc oxide (AZO).

[0058] The present invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided, and the substrate is a glass ribbon in a metal float bath. The substrate is floating in the metal float bath. The substrate has a temperature. The temperature of the substrate is less than 850°C, preferably less than 800°C, most preferably less than 750°C, most preferably less than 725°C, and greater than 400°C, preferably greater than 550°C, more preferably greater than 575°C, most preferably greater than 600°C. For example, the temperature can be about 650°C. While the substrate is at the above temperature, a boron precursor is applied onto the substrate. Optionally, a silicon precursor is applied before, during, or immediately after the application of the boron precursor. Preferably, while the substrate is at the above temperature, a silicon precursor is applied onto the substrate. Optionally, a nanoparticle precursor is applied before, during, or immediately after the application of the boron precursor. Alternatively, nanoparticles cannot be applied, whereby the coated article does not have nanoparticles in the internal light extraction layer.

[0059] The present invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided, and the substrate is a glass ribbon in a metal float bath. The substrate is floating in the metal float bath. The substrate has a temperature. A nanoparticle precursor is applied to the substrate such that the nanoparticles are either completely embedded in the substrate or partially embedded in the substrate. The temperature of the substrate is less than 850°C, preferably less than 800°C, most preferably less than 750°C, most preferably less than 725°C, and greater than 500°C, preferably greater than 550°C, more preferably greater than 575°C, most preferably greater than 600°C. For example, the temperature can be about 650°C. While the substrate is at the aforementioned temperature, a boron precursor is applied onto the substrate and onto the nanoparticles. Optionally, a silicon precursor is applied before, during, or immediately after the application of the boron precursor. While the substrate is at the aforementioned temperature, any silicon precursor can be applied onto the substrate.

[0060] The present invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided, and the substrate is a glass ribbon in a metal float bath. The substrate is floating in the metal float bath. The substrate has a temperature. A nanoparticle precursor is applied to the substrate such that the nanoparticles are either completely embedded in the substrate or partially embedded in the substrate. The temperature of the substrate is less than 850°C, preferably less than 800°C, most preferably less than 750°C, most preferably less than 725°C, and greater than 500°C, preferably greater than 550°C, more preferably greater than 575°C, most preferably greater than 600°C. For example, the temperature can be about 650°C. While the substrate is at the aforementioned temperature, a boron precursor is applied onto the substrate and onto the nanoparticles. The boron precursor may be applied simultaneously with (e.g., co-precipitated with) the application of the nanoparticle precursor or immediately after the nanoparticle precursor is applied. Optionally, a silicon precursor is applied before, during, or immediately after the application of the boron precursor.

[0061] The present invention further relates to a method for forming a light extraction layer on a substrate. A substrate is provided, and the substrate is glass or a glass ribbon. The nanoparticle precursor is applied to the substrate such that the nanoparticles are completely embedded in the substrate, partially embedded in the substrate, or placed on the substrate. The substrate has a temperature. The temperature is 650 °C or lower, preferably 630 °C or lower, more preferably 620 °C or lower, most preferably 610 °C or lower, and / or a temperature of at least 400 °C, preferably at least 500 °C, more preferably at least 525 °C, most preferably at least 550 °C. For example, the temperature of the substrate 10 may be about 600 °C. While the substrate is at the above temperature, a boron precursor is applied onto the substrate. Optionally, a silicon precursor is applied before, during, or immediately after the application of the first boron precursor and / or the second boron precursor.

[0062] The present invention further relates to a method for forming a light extraction layer on a substrate. A substrate is provided, and the substrate is glass or a glass ribbon. The nanoparticle precursor is applied to the substrate such that the nanoparticles are completely embedded in the substrate, partially embedded in the substrate, or placed on the substrate. The substrate has a temperature. The temperature is 650 °C or lower, preferably 630 °C or lower, more preferably 620 °C or lower, most preferably 610 °C or lower, and / or a temperature of at least 400 °C, preferably at least 500 °C, more preferably at least 525 °C, most preferably at least 550 °C. For example, the temperature of the substrate 10 may be about 600 °C. While the substrate is at the above temperature, a boron precursor is applied onto the substrate. The boron precursor may be applied simultaneously with the application of the nanoparticle precursor (e.g., co-precipitation), or immediately after the nanoparticle precursor is applied. Optionally, a silicon precursor is applied before, during, or immediately after the application of the first boron precursor and / or the second boron precursor.

[0063] The present invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided, and the substrate is glass or a glass ribbon. The nanoparticle precursor is applied to the substrate such that the nanoparticles are completely embedded in the substrate, partially embedded in the substrate, or placed on the substrate. The substrate has a temperature. The temperature is a temperature of 500°C or less, preferably 300°C or less, more preferably 200°C or less, and most preferably 100°C or less. For example, the temperature of the substrate 10 may be between 20 and 25°C, or may be room temperature. While the substrate is at the above temperature, a boron precursor is applied onto the substrate. Optionally, a silicon precursor is applied before, during, or immediately after the application of the first boron precursor and / or the second boron precursor.

[0064] The present invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided, and the substrate is glass or a glass ribbon. The nanoparticle precursor is applied to the substrate such that the nanoparticles are completely embedded in the substrate, partially embedded in the substrate, or placed on the substrate. The substrate has a temperature. The temperature is a temperature of 500°C or less, preferably 300°C or less, more preferably 200°C or less, and most preferably 100°C or less. For example, the temperature of the substrate 10 may be between 20 and 25°C, or may be room temperature. While the substrate is at the above temperature, a boron precursor is applied onto the substrate. The boron precursor may be applied simultaneously with the application of the nanoparticle precursor (e.g., co-precipitation), or immediately after the nanoparticle precursor is applied. Optionally, a silicon precursor is applied before, during, or immediately after the application of the first boron precursor and / or the second boron precursor.

[0065] In another embodiment, the present invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided, and the substrate is a glass ribbon in a metal float bath. The substrate is floating in the metal float bath. The substrate has a temperature. The light extraction layer is formed on the substrate or partially embedded in the substrate. The temperature of the substrate is less than 850 °C, preferably less than 800 °C, most preferably less than 750 °C, most preferably less than 725 °C, and greater than 500 °C, preferably greater than 550 °C, more preferably greater than 575 °C, most preferably greater than 600 °C. For example, the temperature can be about 650 °C. While the substrate is at a temperature that forms the first portion of the light extraction layer, a first boron precursor is applied onto the substrate. The nanoparticle precursor is applied after the first portion of the light extraction layer such that the nanoparticles are completely or partially embedded within the first portion of the light extraction layer. The nanoparticle precursor can be applied when the temperature of the substrate coated with the first portion of the light extraction layer is less than 850 °C, preferably less than 800 °C, most preferably less than 750 °C, most preferably less than 725 °C, and greater than 500 °C, preferably greater than 550 °C, more preferably greater than 575 °C, most preferably greater than 600 °C. For example, the temperature can be about 650 °C. Alternatively, the temperature when the nanoparticle precursor is applied can be 650 °C or less, preferably 630 °C or less, more preferably 620 °C or less, most preferably 610 °C or less, and / or a temperature of at least 400 °C, preferably at least 500 °C, more preferably at least 525 °C, most preferably at least 550 °C. For example, the temperature of substrate 10 can be about 600 °C. Alternatively, the temperature when the nanoparticle precursor is applied can be 500 °C or less, preferably 300 °C or less, more preferably 200 °C or less, most preferably 100 °C or less. For example, the temperature of substrate 10 can be between 20 - 25 °C or can be at room temperature. A second boron precursor is generally applied onto the nanoparticles so as to produce a smooth surface, and its average surface roughness is less than 5 nm.When the temperature of the substrate and the nanoparticles coated in the first part of the light extraction layer is less than 850 °C, preferably less than 800 °C, most preferably less than 750 °C, most preferably less than 725 °C, and more than 500 °C, preferably more than 550 °C, more preferably more than 575 °C, most preferably more than 600 °C, the second boron precursor can be applied. For example, the temperature can be about 650 °C. Alternatively, when the temperature is 650 °C or less, preferably 630 °C or less, more preferably 620 °C or less, most preferably 610 °C or less, and / or at least 400 °C, preferably at least 500 °C, more preferably at least 525 °C, most preferably at least 550 °C, the second boron precursor can be applied. For example, the temperature can be about 600 °C. Alternatively, the temperature when the second boron precursor is applied can be made to be 500 °C or less, preferably 300 °C or less, more preferably 200 °C or less, most preferably 100 °C or less. For example, the temperature of the substrate can be between 20 and 25 °C, or can be room temperature. The first boron precursor and the second boron precursor can be the same precursor. Optionally, a silicon precursor is applied before, during, or immediately after the application of the first boron precursor and / or the second boron precursor.

[0066] In another embodiment, the present invention further relates to a method of forming a light extraction layer on a substrate. The substrate is provided, and the substrate is a glass ribbon in a metal float bath. The substrate is floating in the metal float bath. The substrate has a temperature. The light extraction layer is formed on the substrate or partially embedded in the substrate. The temperature of the substrate is less than 850°C, preferably less than 800°C, most preferably less than 750°C, most preferably less than 725°C, and greater than 500°C, preferably greater than 550°C, more preferably greater than 575°C, most preferably greater than 600°C. For example, the temperature can be about 650°C. While the substrate is at a temperature at which the first part of the light extraction layer is formed, a first boron precursor is applied onto the substrate. The nanoparticle precursor is applied after the first part of the light extraction layer such that the nanoparticles are completely or partially embedded within the first part of the light extraction layer. The nanoparticle precursor can be applied when the temperature of the substrate coated with the first part of the light extraction layer is less than 850°C, preferably less than 800°C, most preferably less than 750°C, most preferably less than 725°C, and greater than 500°C, preferably greater than 550°C, more preferably greater than 575°C, most preferably greater than 600°C. For example, the temperature can be about 650°C. Alternatively, the temperature when the nanoparticle precursor is applied can be 650°C or less, preferably 630°C or less, more preferably 620°C or less, most preferably 610°C or less, and / or a temperature of at least 400°C, preferably at least 500°C, more preferably at least 525°C, most preferably at least 550°C. For example, the temperature of substrate 10 can be about 600°C. Alternatively, the temperature when the nanoparticle precursor is applied can be 500°C or less, preferably 300°C or less, more preferably 200°C or less, most preferably 100°C or less. For example, the temperature of substrate 10 can be between 20 - 25°C or can be at room temperature. A second boron precursor is generally applied onto the nanoparticles so as to produce a smooth surface, and its average surface roughness is less than 5 nm.When the temperature of the substrate and the nanoparticles coated in the first part of the light extraction layer is less than 850 °C, preferably less than 800 °C, most preferably less than 750 °C, most preferably less than 725 °C, and more than 500 °C, preferably more than 550 °C, more preferably more than 575 °C, most preferably more than 600 °C, the second boron precursor can be applied. For example, the temperature can be about 650 °C. Alternatively, when the temperature is 650 °C or less, preferably 630 °C or less, more preferably 620 °C or less, most preferably 610 °C or less, and / or at least 400 °C, preferably at least 500 °C, more preferably at least 525 °C, most preferably at least 550 °C, the second boron precursor can be applied. For example, the temperature may be about 600 °C. Alternatively, the temperature when the second boron precursor is applied can be 500 °C or less, preferably 300 °C or less, more preferably 200 °C or less, most preferably 100 °C or less. For example, the temperature of the substrate may be between 20 and 25 °C, or can be room temperature. The second boron precursor may be applied simultaneously with the application of the nanoparticle precursor (e.g., coprecipitation), or immediately after the nanoparticle precursor is applied. The first boron precursor and the second boron precursor can be the same precursor. Optionally, a silicon precursor is applied before, during, or immediately after the application of the first boron precursor and / or the second boron precursor.

Example

[0067] [Example 1]

[0068] A substrate having an internal light extraction layer was formed. The light extraction layer was applied onto a glass ribbon in a tin float bath, and glass with a thickness of 2.0 mm was fabricated using the line speed. When the temperature of the glass ribbon was about 725 °C, trimethyl borate, which is a boron precursor, was applied to the glass ribbon. Based on the understanding of the boron precursor, the temperature may be in the range of 600 - 725 °C. The obtained product had an internal light extraction layer integrated with the glass. The light extraction layer contained 20 - 30 atomic % boron and 10 - 20 atomic % silicon (excluding oxygen) in the form of borate (B2O3) and silica (SiO2). Therefore, the internal light extraction layer was composed of borosilicate. The glass ribbon was cooled, cut, and packaged. Thereby, a third party can apply a transparent conductive oxide coating and / or other OLED panel coatings. [Example 2]

[0069] A substrate having a light extraction layer containing nanoparticles was formed. The substrate was soda-lime glass. A titanium precursor, namely titanium isopropoxide, was applied onto the glass. A boron precursor, namely trimethyl borate, was applied to form a borate layer, coating the titania particles and generating a smooth surface. This process was carried out in a low-temperature furnace, and the temperature was sufficient to deposit titania particles on the glass surface and cover the particles with a smooth B2O3 layer. The temperature was about 600 °C. The obtained layer had titania particles completely embedded in the B2O3 layer at a depth of 0.7 micron, and the thickness of the B2O3 layer was 1 - 1.25 microns.

[0070] This morphology means that the B2O3 layer can be formed first, then the TiO2 particles can be applied and embedded within the B2O3 layer. Alternatively, it means that 0.3 micron of B2O3 can be applied first, and then the titania particles and the B2O3 precursor can be co-precipitated to form the upper part of the light extraction layer.

[0071] According to the XPS analysis of the light extraction layer, silicon was present within the B2O3 layer, which was caused by the diffusion of silicon from the glass into the B2O3 layer, thereby indicating that borosilicate was formed. This means that when depositing the boron precursor, the need to deposit or co-deposit a silicon precursor can be eliminated, yet still means that a borosilicate layer can be formed.

[0072] The present invention is further described in the following numbered clauses.

[0073] Clause 1: A light extraction substrate comprising a glass including a first surface and a second surface, and a light extraction layer on the first surface, wherein the light extraction layer comprises borosilicate.

[0074] Clause 2: The light extraction substrate according to clause 1, wherein the light extraction layer further comprises nanoparticles.

[0075] Clause 3: The light extraction substrate according to clause 1 or 2, wherein the nanoparticles are a high refractive index material.

[0076] Clause 4: The light extraction substrate according to clause 2 or 3, wherein the nanoparticles are titania.

[0077] Clause 5: The light extraction substrate according to any one of clauses 1 to 4, wherein the light extraction layer has an average surface roughness of less than 5 nm.

[0078] Clause 6: The light extraction substrate according to any one of clauses 2 to 5, wherein the nanoparticles have a diameter of up to 40 nm.

[0079] Clause 7: The light extraction substrate according to any one of clauses 1 to 6, wherein the light extraction layer has a thickness of up to 2 μm.

[0080] Clause 8: The light extraction substrate according to any one of Clauses 1 to 7, further comprising a second light extraction layer on or adjacent to the second surface, the second light extraction layer having a surface roughness of at least 10 nm.

[0081] Clause 9: The light extraction substrate according to Clause 8, wherein the surface roughness of the second light extraction layer is at least 50 nm and at most 500 nm.

[0082] Clause 10: The light extraction substrate according to Clause 8, wherein the second light extraction layer is formed by texturing the second surface of the glass.

[0083] Clause 11: The light extraction substrate according to any one of Clauses 1 to 10, further comprising a haze of at least 20%, preferably at least 30%, more preferably at least 35%, and most preferably at least 37%.

[0084] Clause 12: The light extraction substrate according to any one of Clauses 1 to 11, further comprising an anode deposited on the first surface of the glass.

[0085] Clause 13: The light extraction substrate according to any one of Clauses 1 to 12, further comprising an underlayer coating stack deposited on the first surface of the glass.

[0086] Clause 14: An organic light emitting device comprising a substrate having a first surface and a second surface, a light extraction layer on the first surface of the substrate, the light extraction layer comprising a borosilicate layer, a transparent conductive oxide layer on the light extraction layer, a light emitting layer, and a cathode.

[0087] Clause 15: The organic light emitting device according to Clause 14, wherein the light extraction layer further comprises nanoparticles.

[0088] Clause 16: The organic light emitting device according to Clause 15, wherein the nanoparticles are a high refractive index material.

[0089] Clause 17: The organic light-emitting device according to Clause 15 or 16, wherein the nanoparticles are titania.

[0090] Clause 18: The organic light-emitting device according to any one of Clauses 14 to 17, wherein the light extraction layer has an average surface roughness of less than 5 nm.

[0091] Clause 19: The organic light-emitting device according to any one of Clauses 14 to 18, wherein the nanoparticles have a maximum diameter of 5 nm.

[0092] Clause 20: The organic light-emitting device according to any one of Clauses 14 to 19, wherein the light extraction layer has a maximum thickness of 2 μm.

[0093] Clause 21: The organic light-emitting device according to any one of Clauses 14 to 20, further comprising an external light extraction layer disposed on a second surface of a substrate having an average surface roughness of at least 50 nm.

[0094] Clause 22: The organic light-emitting device according to any one of Clauses 14 to 21, further comprising a second light extraction layer on or adjacent to the second surface, the second light extraction layer having a surface roughness of at least 10 nm.

[0095] Clause 23: The organic light-emitting device according to Clause 22, wherein the surface roughness of the second light extraction layer is at least 50 nm and at most 500 nm.

[0096] Clause 24: The organic light-emitting device according to Clause 22 or 23, wherein the second light extraction layer is formed by texturing the surface of the second surface of the glass.

[0097] Clause 25: The organic light-emitting device according to any one of Clauses 14 to 24, further comprising a haze of at least 20%, preferably at least 30%, more preferably at least 35%, and most preferably at least 37%.

[0098] Clause 26: The organic light-emitting device according to any one of Clauses 24 to 25, further comprising an anode deposited on the first surface of the glass.

[0099] Clause 27: An organic light-emitting device according to any one of Clauses 14 to 26, further comprising an underlying coating stack deposited on a first surface of the glass.

[0100] Clause 28: A method of fabricating a light extraction substrate, comprising pouring a glass melt onto a molten metal bath and applying a boron precursor onto the glass melt while the temperature of the glass melt is at least 600 °C and does not exceed 725 °C.

[0101] Clause 29: The method according to Clause 28, wherein the boron precursor is applied to the glass melt to form borosilicate.

[0102] Clause 30: The method according to Clause 28 or 29, wherein the temperature of the glass melt is at least 650 °C and the boron precursor is applied without a silicon precursor to form borosilicate.

[0103] Clause 31: The method according to any one of Clauses 28 to 30, further comprising applying a silicon precursor to form borosilicate.

[0104] Clause 32: The method according to any one of Clauses 28 to 31, further comprising applying a silicon precursor while the temperature of the glass melt is at least 600 °C and does not exceed 725 °C.

[0105] Clause 33: The method according to any one of Clauses 28 to 32, further comprising applying a nanoparticle precursor to form nanoparticles within a layer formed by the boron precursor.

[0106] Clause 34: The method according to any one of Clauses 28 to 33, further comprising applying a silicon precursor simultaneously with applying the boron precursor step.

[0107] Clause 35: The method according to Clause 33 or 34, wherein the nanoparticle precursor is applied simultaneously with the application step of the boron precursor.

[0108] Clause 36: The method according to any one of Clauses 33 to 35, wherein the nanoparticle precursor contains titanium tetrachloride.

[0109] Clause 37: The method according to any one of Clauses 33 to 36, wherein the nanoparticles contain titania.

[0110] Clause 38: A method of manufacturing a light extraction substrate, the method including pouring a glass melt containing silicon or silica onto a molten metal bath and applying a boron precursor onto the glass melt while the temperature of the glass melt is at least 600 °C and does not exceed 725 °C, wherein the silicon or silica in the glass melt reacts with the boron precursor to form borosilicate on the glass melt.

[0111] Clause 39: The method according to Clause 38, wherein the temperature of the glass melt is at least 650 °C and the boron precursor is applied without a silicon precursor to form borosilicate.

[0112] Clause 40: The method according to Clause 38, wherein the temperature of the glass melt is less than 850 °C and further includes applying a silicon precursor.

[0113] Clause 41: The method according to any one of Clauses 38 to 40, further including applying a nanoparticle precursor to form nanoparticles in the layer formed by the boron precursor.

[0114] Clause 42: The method according to Clause 38, 40, or 41, further including applying a silicon precursor simultaneously with applying the boron precursor step.

[0115] Clause 43: The method according to any one of Clauses 38 to 42, wherein the nanoparticle precursor is applied simultaneously with the step of applying the boron precursor.

[0116] Clause 44: The method according to Clause 43, wherein the nanoparticle precursor contains titanium tetrachloride.

[0117] Clause 45: The method according to clause 43 or 44, wherein the nanoparticles contain titania.

[0118] Clause 46: A method for manufacturing a light extraction substrate, the method comprising pouring a glass melt containing silicon onto a molten metal bath, applying a boron precursor onto the glass melt having a temperature of less than 725 °C, and applying a silicon precursor onto the glass melt having a temperature of less than 725 °C, wherein the silicon precursor and the boron precursor form borosilicate on or within the glass melt.

[0119] Clause 47: The method according to clause 46, wherein the boron precursor is applied to the glass melt to produce borosilicate within the glass melt.

[0120] Clause 48: The method according to clause 46 or 47, further comprising applying a nanoparticle precursor to form nanoparticles within the layer formed by the boron precursor.

[0121] Clause 49: The method according to any one of clauses 46 to 48, further comprising applying the silicon precursor simultaneously with applying the boron precursor process.

[0122] Clause 50: The method according to clause 48 or 49, wherein the nanoparticle precursor is applied simultaneously with the application step of the boron precursor.

[0123] Clause 51: The method according to any one of clauses 48 to 50, wherein the nanoparticle precursor contains titanium tetrachloride.

[0124] Clause 52: The method according to any one of clauses 48 to 51, wherein the nanoparticles contain titania.

[0125] Clause 53: The method according to any one of clauses 46 to 51, wherein the light extraction substrate contains at least 20%, preferably at least 30%, more preferably at least 35%, and most preferably at least 37% haze.

[0126] Although the present invention has been described in detail for purposes of illustration based on what is currently considered to be the most practical and preferred embodiments, such details are for that purpose only, and the present invention is not limited to the disclosed embodiments, but rather is intended to cover modifications and equivalent configurations within the spirit and scope of the appended claims. For example, it should be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.

Claims

Claim 1 A method of fabricating a light extraction substrate, comprising: pouring a glass melt onto a molten metal bath; applying a boron precursor onto the glass melt while the glass melt has a temperature of at least 600° C. to produce borosilicate; applying a nanoparticle precursor onto the glass melt to produce a light extraction substrate; wherein applying the nanoparticle precursor forms nanoparticles within a light extraction layer formed by the boron precursor; and wherein the nanoparticles are present in the light extraction layer in the range of 0.1 wt % to 20 wt % and are at least partially embedded within the light extraction substrate. Claim 2 The method of claim 1, wherein the temperature of the glass melt is 725° C. or less. Claim 3 The method of claim 1, wherein the boron precursor is applied without a silicon precursor to produce borosilicate. Claim 4 The method of claim 1, further comprising applying a silicon precursor to produce borosilicate. Claim 5 The method of claim 1, wherein the nanoparticle precursor comprises titanium tetrachloride.

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