Patent Description:
This invention relates to forming a borosilicate layer within or over a substrate, for example glass or a glass ribbon, and optionally embedding nanoparticles into the borosilicate layer. This invention also relates to organic light emitting diodes, solar or photovoltaic (PV) cells, daylighting windows, and, more particularly, to a substrate having increased light scattering for improved light utilization.

An organic light emitting diode ("OLED") is a light-emitting device having an emissive electroluminescent layer incorporating organic compounds. The organic compounds emit light in response to an electric current. Typically, an emissive layer of organic semiconductor material is situated between two electrodes (an anode and a cathode). When an electric current is passed between the anode and the cathode, the organic material emits light. OLEDs are used in numerous applications, such as television screens, computer monitors, mobile phones, PDAs, watches, lighting, and various other electronic devices.

OLEDs provide numerous advantages over conventional inorganic devices, such as liquid crystal displays. For example, an OLED functions without the need for a back light. In low ambient light, such as a dark room, an OLED screen can achieve a higher contrast ratio than conventional liquid crystal displays. OLEDs are also thinner, lighter, and more flexible than liquid crystal displays and other lighting devices.

In making OLEDs, one typically adds a light extraction region wherein nanoparticles are embedded partially or completely within the light extraction region. For example, nanoparticles may be embedded within the substrate. When the substrate is glass, the nanoparticles must be embedded while the substrate is at a temperate of greater than <NUM>, typically greater than <NUM>. There is a need for embedding nanoparticles into a glass substrate when the glass ribbon is at a lower temperature, such as less than or equal to <NUM>. <CIT> and <CIT> disclose light extraction substrates comprising a borosilicate light extraction layer with nanoparticles in it. <CIT> discloses a method of manufacturing a glass substrate. <CIT> discloses an OLED with an internal scattering layer.

The invention relates to a light extraction substrate as defined in claim <NUM>. The light extraction substrate may further comprise an external light extraction layer over or on the second surface of the substrate. The internal light extraction layer is a part of the substrate.

In another embodiment, the invention relates to an organic light emitting diode ("OLED"), as defined in claim <NUM>.

Another embodiment of the invention relates to a method of making a light extraction substrate as defined in claim <NUM>.

As used herein, spatial or directional terms, such as "left", "right", "inner", "outer", "above", "below", and the like, relate to the invention as it is shown in the drawing figure. However, it is to be understood that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. Further, as used herein, all numbers expressing dimensions, physical characteristics, processing parameters, quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical values set forth in the following specification and claims may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical value should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Moreover, all ranges disclosed herein are to be understood to encompass the beginning and ending range values and any and all subranges subsumed therein. For example, a stated range of "<NUM> to <NUM>" should be considered to include any and all subranges between (and inclusive of) the minimum value of <NUM> and the maximum value of <NUM>; that is, all subranges beginning with a minimum value of <NUM> or more and ending with a maximum value of <NUM> or less, e.g., <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, and the like. Any reference to amounts, unless otherwise specified, is "by weight percent".

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 the layers are present than is the first layer. The second layer can be in direct contact with the first layer or one or more other layers can be located between the second layer and the first layer.

Any reference to amounts, unless otherwise specified, is "by weight percent".

The term "film" means a region having a desired or selected composition. A "layer" comprises one or more "films". A "coating" is comprised of one or more "layers". The term "organic material" includes polymers as well as small molecule organic materials that can be used to fabricate organic opto-electronic devices.

The term "visible light" means electromagnetic radiation having a wavelength in the range of <NUM> to <NUM>. The term "infrared radiation" means electromagnetic radiation having a wavelength in the range of greater than <NUM> to <NUM>,<NUM>. The term "ultraviolet radiation" means electromagnetic energy having a wavelength in the range of <NUM> to less than <NUM>.

The terms "metal" and "metal oxide" include silicon and silica, respectively, as well as traditionally recognized metals and metal oxides, even though silicon may not be conventionally considered a metal. The term "curable" means a composition capable of polymerizing or crosslinking. By "cured" is meant that the material is at least partly polymerized or cross-linked, preferably fully polymerized or cross-linked. By "at least" is meant "greater than or equal to". By "not more than" is meant "less than or equal to". The terms "upstream" and "downstream" refer to the direction of travel of the glass ribbon.

Haze and transmittance values herein are those determined using a Haze-Gard Plus hazemeter (commercially available from BYK-Gardner USA) or a Perkin Elmer Lamda <NUM> Spectrophotometer. Surface roughness values are those determined using an Instrument Dimension <NUM> Atomic Force Microscope.

The discussion of the invention may describe certain features as being "particularly" or "preferably" within certain limitations (e.g., "preferably", "more preferably", "even more preferably", or "most preferably" within certain limitations). It is to be understood that the invention is not limited to these particular or preferred limitations but encompasses the entire scope of the disclosure.

The invention comprises, consists of, or consists essentially of, the following aspects of the invention, in any combination. Various aspects of the invention are illustrated in separate drawing figures. However, it is to be understood that this is simply for ease of illustration and discussion. In the practice of the invention, one or more aspects of the invention shown in one drawing figure can be combined with one or more aspects of the invention shown in one or more of the other drawing figures.

The invention relates to a substrate that comprises a light extraction layer <NUM> with nanoparticles <NUM> embedded in the light extraction layer <NUM>. As shown in <FIG>, a substrate <NUM> is provided. The substrate <NUM> can have a high visible light transmission. By "high visible light transmission" is meant a visible light transmission at a reference wavelength of <NUM> nanometers (nm) and a reference thickness of <NUM> of at least <NUM>%, such as at least <NUM>%. For example, such as at least <NUM>%. For example, such as at least <NUM>%. For example, such as at least <NUM>%. For example, such as at least <NUM>%. The substrate <NUM> having the light extraction layer <NUM> and nanoparticles <NUM> can have a haze of at least <NUM>%, preferably at least <NUM>%, more preferably at least <NUM>%, most preferably at least <NUM>%.

The substrate <NUM> can be glass. For example, the substrate <NUM> can be a low iron glass. By "low iron" is meant having a total Iron content of less than <NUM> parts per million (ppm), such as less than <NUM> ppm. For example, the total iron content can be less than <NUM> ppm. For example, the total iron content can be less than <NUM> ppm. Examples of suitable materials for the substrate <NUM> include soda-lime silicate glass, for example, float glass. The substrate <NUM> can be a glass ribbon. Glass ribbon is a hot glass that floats on a metal bath (e.g. tin bath), and is gradually cooled while floating on the metal bath. The glass ribbon is gradually cool from about <NUM> to approximately <NUM> while on the metal bath.

The substrate <NUM> can be of any desired thickness. For example, the substrate <NUM> can have a thickness in the range of <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>. For example, the substrate <NUM> can have a thickness in the range of <NUM> to <NUM>.

The substrate <NUM> has a first surface <NUM> and a second surface <NUM>. The second surface <NUM> is opposite the first surface <NUM>.

As shown in <FIG>, a light extraction layer <NUM> is positioned over at least a portion of the first surface <NUM>, or partially embedded within the substrate <NUM>. The light extraction layer <NUM> comprises borosilicate. Borosilicate is a glass that contains silica (SiO<NUM>) and boron trioxide (B<NUM>O<NUM>). The light extraction layer <NUM> with nanoparticles <NUM> is generally smooth, and can have an average surface roughness of less than <NUM>.

The light extraction layer <NUM> may be formed over the first surface <NUM> of the substrate <NUM> according to the following method. The substrate <NUM> can be glass. The substrate <NUM> is provided at a temperature of no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>; and/or at a temperature of at least <NUM>; preferably at least <NUM>; more preferably at least <NUM>; most preferably at least <NUM>. For example, substrate <NUM> may be at a temperature of about <NUM>. The light extraction layer <NUM> is applied by applying a boron precursor that will form a borosilicate. The boron precursor can be tri-methyl borate, tri-ethyl borate, phenylboron dichloride, boron bromide or boron fluoride. In one non-limiting embodiment, the boron precursor is tri-methyl borate. When the boron precursor is applied to the substrate <NUM> within the temperature described in this paragraph, the silicon can diffuse from the glass substrate <NUM> and react with the boron species to form the borosilicate. If the temperature is below <NUM>, it is unlikely that the boron precursor will form B<NUM>O<NUM>.

If the temperature is above <NUM>, it is likely that the light extraction layer <NUM> will form (at least in part) within the substrate <NUM> (as shown in <FIG>). Thus, an embodiment of the invention is shown in <FIG>, wherein the light extraction layer <NUM> is positioned, partially or entirely, within; or can be an integral part of the substrate <NUM>. In this embodiment, the light extraction layer <NUM> is positioned partially or entirely beneath the first surface <NUM>, or entirely beneath the first surface and between the first surface <NUM> and the second surface <NUM>.

The light extraction layer <NUM> may be formed over the first surface <NUM> of the substrate <NUM> in several ways. One method is related to an embodiment wherein the substrate is glass, for example float glass or soda-lime glass. In this method, a glass melt is poured onto a metal bath to form a glass ribbon. A boron precursor is applied over glass ribbon. The boron precursor is applied when the glass ribbon has a temperature at or below <NUM>; and at or above <NUM>. For example, the glass ribbon can be at a temperate of about <NUM>.

When the borosilicate is applied to a glass ribbon when the glass ribbon is at least <NUM>, some of the silicon in the glass ribbon diffuses into the borate layer to form a borosilicate coating.

In an example not according to the claimed invention, the boron precursor can alternatively be applied over the substrate <NUM> when the substrate is below <NUM>, preferably below <NUM>, more preferably below <NUM>, most preferably below <NUM>. For example, the substrate can have a temperature of approximately <NUM>-<NUM>, or can be at room temperature.

Optionally, a silicon precursor can be applied before, 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, methyl chlorosilane, ethyl chlorosilane, or silicon chloride. In one non-limiting example, the silicon precursor is tetraethyl orthosilicate.

For example, the silicon precursor can be supplied into a vaporizer at the same time that the boron precursor is supplied into the vaporizer. The silicon precursor and boron precursor are vaporized by the vaporizer at the same time forming a vaporized boron and silicon precursors. The vaporized boron and silicon precursors can be fed into a coater where the vaporized boron and silicon precursors are applied to the glass ribbon.

In another example, the silicon precursor can be fed into a first vaporizer. The first vaporizer vaporizes the silicon precursor forming a vaporized silicon precursor. The vaporized silicon precursor is fed into a coater, which applies the vaporized silicon precursor onto the glass ribbon. After the vaporized silicon precursor is applied to the glass ribbon, a vaporized boron precursor is applied to the glass ribbon, which contains the vaporized and applied silicon precursor. The vaporized boron precursor is formed by feeding a boron precursor into a second vaporizer. The second vaporizer vaporizes the boron precursor. The vaporized boron precursor is fed to a second coater, which applies the vaporized boron precursor to the glass ribbon, which contains the vaporized and applied vaporized silicon precursor. The application of the vaporized silicon precursor and the vaporized boron precursor forms a borosilicate layer, which, depending on the temperature of the glass ribbon, can reside over the glass ribbon, or can be embedded within or become an integral part of the glass ribbon, wherein the top portion of the glass ribbon comprises the borosilicate layer.

In another example, the boron precursor can be fed into a first vaporizer. The first vaporizer vaporizes the boron precursor forming a vaporized boron precursor. The vaporized boron precursor is fed into a coater, which applies the vaporized boron precursor onto the glass ribbon. After the vaporized boron precursor is applied to the glass ribbon, a vaporized silicon precursor is applied to the glass ribbon, which contains the vaporized and applied boron precursor. The vaporized silicon precursor is formed by feeding a silicon precursor into a second vaporizer. The second vaporizer vaporizes the silicon precursor. The vaporized silicon precursor is fed to a second coater, which applies the vaporized silicon precursor to the glass ribbon, which contains the vaporized and applied vaporized boron precursor. The application of the vaporized boron precursor and the vaporized silicon precursor forms a borosilicate layer, which, depending on the temperature of the glass ribbon, can reside over the glass ribbon, or can be embedded within or become an integral part of the glass ribbon, wherein the top portion of the glass ribbon comprises the borosilicate layer.

In another example, the silicon precursor can be fed into a first vaporizer. The first vaporizer vaporizes the silicon precursor forming a vaporized silicon precursor. The vaporized silicon precursor is fed into a coater, which applies the vaporized silicon precursor onto the 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, which contains the vaporized and applied silicon precursor. The vaporized boron precursor and vaporized silicon precursor is formed by feeding a boron precursor and a silicon precursor into a second vaporizer. The second vaporizer vaporizes the boron precursor and the silicon precursor forming a vaporized boron and silicon precursor. The vaporized boron and silicon precursor is fed to a second coater, which applies the vaporized boron and silicon precursor to the glass ribbon, which contains the vaporized and applied vaporized silicon precursor. This forms a borosilicate layer, which, depending on the temperature of the glass ribbon, can reside over the glass ribbon, or can be embedded within or become an integral part of the glass ribbon, wherein the top portion of the glass ribbon comprises the borosilicate layer.

In another example, the silicon precursor and a boron precursor can be fed into a first vaporizer. The first vaporizer vaporizes the silicon precursor and boron precursor forming a vaporized silicon and boron precursor. The vaporized silicon and boron precursor is fed into a coater, which applies the vaporized silicon and boron precursor onto the glass ribbon. After the vaporized silicon and boron precursor is applied to the glass ribbon, a vaporized silicon precursor is applied to the glass ribbon, which contains the vaporized and applied silicon and boron precursor. The vaporized silicon precursor is formed by feeding a silicon precursor into a second vaporizer. The second vaporizer vaporizes the silicon precursor. The vaporized silicon precursor is fed to a second coater, which applies the vaporized silicon precursor to the glass ribbon, which contains the vaporized and applied vaporized silicon and boron precursor. This forms a borosilicate layer, which, depending on the temperature of the glass ribbon, can reside over the glass ribbon, or can be embedded within or become an integral part of the glass ribbon, wherein the top portion of the glass ribbon comprises the borosilicate layer.

In another example, the silicon precursor can be fed into a first vaporizer. The first vaporizer vaporizes the silicon precursor forming a vaporized silicon precursor. The vaporized silicon precursor is fed into a coater, which applies the vaporized silicon precursor onto the glass ribbon. After the vaporized silicon precursor is applied to the glass ribbon, a vaporized boron precursor is applied to the glass ribbon, which contains the vaporized and applied silicon precursor. The vaporized boron precursor is formed by feeding a boron precursor into a second vaporizer. The second vaporizer vaporizes the boron precursor. The vaporized boron precursor is fed to a second coater, which applies the vaporized boron precursor to the glass ribbon, which contains the vaporized and applied vaporized silicon precursor. A second silicon precursor is vaporized and applied via a third vaporizer and third coater similar to how the first silicon precursor was vaporized and applied, except that the third vaporizer and third coater are positioned downstream of the first vaporizer and coater and the second vaporizer and coater. This forms a borosilicate layer, which, depending on the temperature of the glass ribbon, can reside over the glass ribbon, or can be embedded within or become an integral part of the glass ribbon, wherein the top portion of the glass ribbon comprises the borosilicate layer.

In an example not according to the claimed invention, 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 over glass ribbon. The boron precursor is applied to the glass ribbon when the glass ribbon has a temperature of no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>; and/or at a temperature of at least <NUM>; preferably at least <NUM>; more preferably at least <NUM>; most preferably at least <NUM>. For example, the temperature may be about <NUM>. Optionally, a silicon precursor can be applied before, simultaneously, or immediately after the boron precursor is applied to form a borosilicate in the same manner as described above. By this method, the light extraction layer <NUM> would form a distinct borate or borosilicate layer applied over the first surface, but rather integrated into the substrate <NUM> as if it is part of the substrate.

The light extraction layer <NUM> can have a thickness of at least <NUM> microns, preferably at least <NUM> microns, more preferably at least <NUM> microns, most preferably at least <NUM> micron. The light extraction layer <NUM> can have a thickness of at most <NUM> microns, preferably at most <NUM> microns, more preferably at most <NUM> microns, most preferably at most <NUM> micron. In certain embodiments, the extraction layer <NUM> is positioned over the first surface <NUM> of the substrate, the light extraction layer <NUM> can have a thickness of at least <NUM> microns, preferably at least <NUM> microns, more preferably at least <NUM> microns, most preferably at least <NUM> micron; and can have a thickness of at most <NUM> microns, preferably at most <NUM> microns, more preferably at most <NUM> microns, most preferably at most <NUM> micron. In other embodiments, the light extraction layer <NUM> is embedded or partially embedded in the first surface <NUM> of the substrate <NUM>, the light extraction layer <NUM> can have a thickness of at least <NUM> microns, preferably at least <NUM> microns, more preferably at least <NUM> microns, most preferably at least <NUM> micron; and can have a thickness of at most <NUM> microns, preferably at most <NUM> microns, more preferably at most <NUM> microns, most preferably at most <NUM> micron.

Nanoparticles <NUM> are embedded in the light extraction layer <NUM>. The nanoparticles may be a material that has a higher refractive index than the substrate, i.e., is a high index of refraction material. For example, the nanoparticles <NUM> may be metal oxides. For example, the nanoparticles <NUM> may be alumina, titania, cerium oxide, zinc oxide, tin oxide, silica, zirconia, mixtures thereof or alloys thereof. Other examples include metallic nanoparticles. For example but not limited to iron, steel, copper, silver, gold, and titanium. 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 specific embodiment, the nanoparticles comprise titania.

The nanoparticles <NUM> can have a diameter of up to <NUM>, preferably up to <NUM>, more preferably up to <NUM>; most preferably up to <NUM>. The nanoparticles <NUM> can have a diameter of at least <NUM>, preferably at least <NUM>, more preferably at least <NUM>; most preferably at least <NUM>.

The nanoparticles <NUM> in the light extraction layer <NUM> can be present in the range of <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> to <NUM> weight percent, such as <NUM> to <NUM> weight percent, such as <NUM> to <NUM> weight percent, such as <NUM> to <NUM> weight percent, such as <NUM> to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent, such as <NUM> weight percent to <NUM> weight percent.

As shown in <FIG>, in one embodiment, the article <NUM> may further comprise an external light extraction layer <NUM> positioned over the second surface <NUM> of the substrate <NUM>. The external light extraction layer <NUM> can be formed by a coating, such as a metal oxide coating, having a roughened exterior surface. Examples of oxides useful for the external light extraction layer <NUM> include silica, alumina, zinc oxide, titania, zirconia, tin oxide and/or mixtures or alloys thereof. The external light extraction layer <NUM> can have an average surface roughness (Ra) in the range of <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>; such as <NUM> to <NUM>; such as <NUM> to <NUM>. The external light extraction layer <NUM> can have a root mean square roughness (Rq) in the range of <NUM> to <NUM>, such as <NUM> to <NUM>. The external light extraction layer <NUM> can have a thickness in the range of <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>. The external light extraction layer <NUM> can be a single layer or optionally a multilayer coating.

The roughness in the external light extract layer <NUM> can be created by several techniques. One technique is to form a coating having a roughened exterior surface. The coating can be a metal oxide, such as silica, alumina, zinc oxide, titania, zirconia, tin oxide, or mixtures thereof. Alternatively, the external light extraction layer <NUM> can be formed by texturing the second surface <NUM> of the glass, such as by mechanically roughening the surface of the substrate, such as by mechanical abrasion or chemical etching.

The light extraction layer <NUM> with nanoparticle <NUM> can be used in various applications. In one embodiment, as shown in <FIG>, the article <NUM> is a privacy glazing. The article <NUM> has a substrate <NUM>. A light extraction layer <NUM> is formed over at least a portion of the first surface <NUM> of the substrate <NUM>, or is embedded within the substrate <NUM> at the first surface <NUM>. The light extraction layer <NUM> comprises nanoparticles <NUM> as described above. An optional coating <NUM> may be present. The optional coating <NUM> may be one or more layers as described below used in the OLED article. For example, the optional coating <NUM> may be an anode layer. Alternatively, the optional coating <NUM> can be a metal oxide, metal nitride, metal oxynitrides or metal. For example, the optional coating <NUM> may be zinc oxide, zinc stannate, tin oxide, silicon nitride, titania, silica, alumina, silver, gold, copper, mixtures thereof or alloys thereof. A light source <NUM> is located adjacent an edge <NUM> of the article <NUM>. When the light source <NUM> is deactivated, the article <NUM> has a first transparency level. When the light source <NUM> is active, the nanoparticles <NUM> scatter the light waves <NUM> from the light source <NUM> and the article has a second transparency level. The second transparency level is less than the first transparency level due to the scatting of the light waves <NUM> by the nanoparticles <NUM>.

In another embodiment, the light extraction layer <NUM> can be used in an organic light emitting diode ("OLED"). Thus, the article <NUM> is an OLED. In this embodiment, as shown in <FIG>, the OLED <NUM> includes a substrate <NUM>, a light extraction layer <NUM> comprising a nanoparticle <NUM> over a first surface <NUM> of the substrate <NUM>, the external light extraction layer <NUM> over a second surface <NUM> of the substrate <NUM>, a cathode <NUM>, an emissive layer <NUM> and an anode <NUM>.

The cathode <NUM> can be any conventional OLED cathode. Examples of suitable cathodes <NUM> include (but are not limited to) barium and calcium.

The emissive layer <NUM> can be a conventional organic electroluminescent layer as known in the art. Examples of such materials include, but are not limited to, small molecules such as organometallic chelates (e.g., Alq<NUM>), fluorescent and phosphorescent dyes, and conjugated dendrimers. Examples of suitable materials include triphenylamine, perylene, rubrene, and quinacridone. Alternatively, electroluminescent polymeric materials are also known. Examples of such conductive polymers include poly(p-phenylene vinylene) and polyfluorene. Phosphorescent materials could also be used. Examples of such materials include polymers such as poly(n-vinylcarbazole) in which an organometallic complex, such as an iridium complex, is added as a dopant.

The anode <NUM> can be a conductive, transparent material, such as a metal oxide material, such as, but not limited to, iridium tin oxide (ITO) or aluminum-doped zinc oxide (AZO).

The invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided wherein the substrate is a glass ribbon in a metal float bath. The substrate is floating on the metal float bath. The substrate has a temperature. The temperature of the substrate is below <NUM>; and above <NUM>. For example, the temperature can be about <NUM>. A boron precursor is applied over the substrate while the substrate is at the temperature. Optionally, a silicon precursor is applied before, during or immediately after the application of the boron precursor. Preferably, the silicon precursor is applied over the substrate while the substrate is at the temperature. Optionally, a nanoparticle precursor is applied before, during or immediately after the application of the boron precursor.

The invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided wherein the substrate is a glass ribbon in a metal float bath. The substrate is floating on the metal float bath. The substrate has a temperature. A nanoparticle precursor is applied to the substrate in a manner that causes the nanoparticles to embed fully or to embed partially within the substrate. The temperature of the substrate is below <NUM>; and above <NUM>. For example, the temperature can be about <NUM>. A boron precursor is applied over the substrate and over the nanoparticles while the substrate is at the temperature. Optionally, a silicon precursor is applied before, during or immediately after the application of the boron precursor. The optional silicon precursor can be applied while the substrate is at the temperature.

The invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided wherein the substrate is a glass ribbon in a metal float bath. The substrate is floating on the metal float bath. The substrate has a temperature. A nanoparticle precursor is applied to the substrate in a manner that causes the nanoparticles to embed fully or to embed partially within the substrate. The temperature of the substrate is below <NUM>; and above <NUM>. For example, the temperature can be about <NUM>. A boron precursor is applied over the substrate and over the nanoparticles while the substrate is at the temperature. The boron precursor may be applied at the same time (e.g. co-precipitated) 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.

An embodiment not forming part of the claimed invention relates to a method of forming a light extraction layer on a substrate. A substrate is provided wherein the substrate is glass or a glass ribbon. A nanoparticle precursor is applied to the substrate in a manner that causes the nanoparticles to embed fully within, to embed partially within, or to rest on top of the substrate. The substrate has a temperature. The temperature of no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>; and/or at a temperature of at least <NUM>; preferably at least <NUM>; more preferably at least <NUM>; most preferably at least <NUM>. For example, substrate <NUM> may be at a temperature of about <NUM>. A boron precursor is applied over the substrate while the substrate is at the temperature. Optionally, a silicon precursor is applied before, during or immediately after the application of the first boron precursor, and/or the second boron precursor.

An embodiment not forming part of the claimed invention relates to a method of forming a light extraction layer on a substrate. A substrate is provided wherein the substrate is glass or a glass ribbon. A nanoparticle precursor is applied to the substrate in a manner that causes the nanoparticles to embed fully within, to embed partially within, or to rest on top of the substrate. The substrate has a temperature. The temperature of no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>; and/or at a temperature of at least <NUM>; preferably at least <NUM>; more preferably at least <NUM>; most preferably at least <NUM>. For example, substrate <NUM> may be at a temperature of about <NUM>. A boron precursor is applied over the substrate while the substrate is at the temperature. The boron precursor may be applied at the same time (e.g. co-precipitated) 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.

An embodiment not forming part of the claimed invention relates to a method of forming a light extraction layer on a substrate. A substrate is provided wherein the substrate is glass or a glass ribbon. A nanoparticle precursor is applied to the substrate in a manner that causes the nanoparticles to embed fully within, to embed partially within, or to rest on top of the substrate. The substrate has a temperature. The temperature of no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>. For example, substrate <NUM> may be at a temperature of between <NUM>-<NUM>, or can be at room temperature. A boron precursor is applied over the substrate while the substrate is at the temperature. Optionally, a silicon precursor is applied before, during or immediately after the application of the first boron precursor, and/or the second boron precursor.

An embodiment not forming part of the claimed invention relates to a method of forming a light extraction layer on a substrate. A substrate is provided wherein the substrate is glass or a glass ribbon. A nanoparticle precursor is applied to the substrate in a manner that causes the nanoparticles to embed fully within, to embed partially within, or to rest on top of the substrate. The substrate has a temperature. The temperature of no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>. For example, substrate <NUM> may be at a temperature of between <NUM>-<NUM>, or can be at room temperature. A boron precursor is applied over the substrate while the substrate is at the temperature. The boron precursor may be applied at the same time (e.g. co-precipitated) 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.

In another embodiment, the invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided wherein the substrate is a glass ribbon in a metal float bath. The substrate is floating on the metal float bath. The substrate has a temperature. A light extraction layer is formed over or partially embedded within the substrate. The temperature of the substrate is below <NUM>; and above <NUM>. For example, the temperature can be about <NUM>. A first boron precursor is applied over the substrate while the substrate is at the temperature forming a first portion of the light extraction layer. A nanoparticle precursor is applied after the first portion of the light extraction layer in a manner that causes the nanoparticles to embed fully or to embed partially within the first portion of the light extraction layer. The nanoparticle precursor can be applied when the substrate coated with the first portion of the light extraction layer is at a temperature of below <NUM>, preferably below <NUM>, most preferably below <NUM>, most preferably below <NUM>; and above <NUM>, preferably above <NUM>, more preferably above <NUM>, most preferably above <NUM>. For example, the temperature can be about <NUM>. Alternatively, the temperature when the nanoparticles precursor is applied can be no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>; and/or at a temperature of at least <NUM>; preferably at least <NUM>; more preferably at least <NUM>; most preferably at least <NUM>. For example, substrate <NUM> may be at a temperature of about <NUM>. Alternatively, the temperature when the nanoparticles precursor is applied can be no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>. For example, substrate <NUM> may be at a temperature of between <NUM>-<NUM>, or can be at room temperature. A second boron precursor is applied over the nanoparticles in a manner that produces a generally smooth surface wherein the average surface roughness is less than <NUM>. The second boron precursor can be applied when the substrate coated with the first portion of the light extraction layer and the nanoparticles has a temperature below <NUM>, preferably below <NUM>, most preferably below <NUM>, most preferably below <NUM>; and above <NUM>, preferably above <NUM>, more preferably above <NUM>, most preferably above <NUM>. For example, the temperature can be about <NUM>. Alternatively, the second boron precursor can be applied when the temperature is no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>; and/or at a temperature of at least <NUM>; preferably at least <NUM>; more preferably at least <NUM>; most preferably at least <NUM>. For example, the temperature may be about <NUM>. Alternatively, the temperature when the second boron precursor is applied can be no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>. For example, the substrate may be at a temperature of between <NUM>-<NUM>, or can be at 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.

In another embodiment, the invention further relates to a method of forming a light extraction layer on a substrate. A substrate is provided wherein the substrate is a glass ribbon in a metal float bath. The substrate is floating on the metal float bath. The substrate has a temperature. A light extraction layer is formed over or partially embedded within the substrate. The temperature of the substrate is below <NUM>; and above <NUM>. For example, the temperature can be about <NUM>. A first boron precursor is applied over the substrate while the substrate is at the temperature forming a first portion of the light extraction layer. A nanoparticle precursor is applied after the first portion of the light extraction layer in a manner that causes the nanoparticles to embed fully or to embed partially within the first portion of the light extraction layer. The nanoparticle precursor can be applied when the substrate coated with the first portion of the light extraction layer is at a temperature of below <NUM>, preferably below <NUM>, most preferably below <NUM>, most preferably below <NUM>; and above <NUM>, preferably above <NUM>, more preferably above <NUM>, most preferably above <NUM>. For example, the temperature can be about <NUM>. Alternatively, the temperature when the nanoparticles precursor is applied can be no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>; and/or at a temperature of at least <NUM>; preferably at least <NUM>; more preferably at least <NUM>; most preferably at least <NUM>. For example, substrate <NUM> may be at a temperature of about <NUM>. Alternatively, the temperature when the nanoparticles precursor is applied can be no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>. For example, substrate <NUM> may be at a temperature of between <NUM>-<NUM>, or can be at room temperature. A second boron precursor is applied over the nanoparticles in a manner that produces a generally smooth surface wherein the average surface roughness is less than <NUM>. The second boron precursor can be applied when the substrate coated with the first portion of the light extraction layer and the nanoparticles has a temperature below <NUM>, preferably below <NUM>, most preferably below <NUM>, most preferably below <NUM>; and above <NUM>, preferably above <NUM>, more preferably above <NUM>, most preferably above <NUM>. For example, the temperature can be about <NUM>. Alternatively, the second boron precursor can be applied when the temperature is no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>; and/or at a temperature of at least <NUM>; preferably at least <NUM>; more preferably at least <NUM>; most preferably at least <NUM>. For example, the temperature may be about <NUM>. Alternatively, the temperature when the second boron precursor is applied can be no more than <NUM>, preferably no more than <NUM>, more preferably no more than <NUM>, most preferably no more than <NUM>. For example, substrate may be at a temperature of between <NUM>-<NUM>, or can be at room temperature. The second boron precursor may be apply at the same time (e.g. co-precipitated) 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 <NUM>. A substrate having an internal light extraction layer was formed. The light extraction layer was applied over a glass ribbon in a tin float bath with a line speed to produce a <NUM> glass. A boron precursor, tri-methyl borate, was applied to the glass ribbon when the glass ribbon had a temperature of about <NUM>. Based on our understanding of the boron precursor, the temperature could be in the range of <NUM>-<NUM>. The resulting product had an internal light extraction layer that was intergrated into the glass. The light extraction layer contained <NUM>-<NUM> atomic % boron, and <NUM>-<NUM> atomic % silicon (excluding oxygen), in the form of borate (B<NUM>O<NUM>) and silica (SiO<NUM>); therefore, the internal light extraction layer comprised a borosilicate. The glass ribbon was cooled, cut and packaged, wherein a third-party could apply transparent conductive oxide coatings and/or other OLED panel coatings.

A substrate having a light extraction layer with nanoparticles was formed. The substrate was a soda lime glass. A titanium precursor, namely titanium isopropoxide, was applied over the glass. A boron precursor, namely tri-methyl borate, was applied to form a borate layer to cover the titania particles and generate a smooth surface. The process was done in a low temperature furnace wherein the temperature was enough to deposit the particles onto the glass surface, and cover the particles with a smooth B<NUM>O<NUM> layer. The temperature was approximately <NUM>. The resulting layer had titania particles fully embedded in the B<NUM>O<NUM> layer at a depth of <NUM> microns, wherein the B<NUM>O<NUM> layer was <NUM>-<NUM> microns thick.

This morphology means that one could form a B<NUM>O<NUM> layer first, then apply the TiO<NUM> particles later and embed the particles into the B<NUM>O<NUM> layer. Alternatively, <NUM> microns of the B<NUM>O<NUM> could be applied first, then the titania particles and B<NUM>O<NUM> precursor could be co-precipitated to form the top portion of the light extraction layer.

Claim 1:
A light extraction substrate comprising a glass (<NUM>), the glass comprising a first surface (<NUM>) and a second surface (<NUM>); and a light extraction layer (<NUM>), wherein the light extraction layer comprises borosilicate, wherein the light extraction layer further comprises a nanoparticle (<NUM>), and characterized in that the light extraction layer (<NUM>) is positioned partially or entirely beneath the first surface (<NUM>) within the substrate.