Quantum dot color conversion device and method of manufacturing same

Abstract

Apparatuses, devices, and methods of forming apparatuses and devices are provided. The apparatus includes a color conversion unit disposed between a first substrate and a second substrate. The color conversion unit includes a low refractive index material layer adjacent to the color filter, wherein the low refractive index material layer or the color filter is adjacent to the first substrate. The color conversion unit further includes a color conversion matrix adjacent the second substrate and one of the low index material layer or the color filter, the color conversion matrix including a plurality of quantum dots within the medium. The color conversion units are defined between the first wall and the second wall, each including an absorbing portion and a reflecting portion. The first substrate extends between the absorbing portion of the first wall and the second wall, and the second substrate extends between the reflecting portion of the first wall and the reflecting portion of the second wall.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority under patent law to U.S. Provisional Application Serial No. 63 / 528201, filed on July 21, 2023, and this application is incorporated herein by reference in its entirety based on its contents. Technical Field

[0003] Embodiments herein relate generally to color converter devices, and more particularly, to the design of color converters for light emitting diode devices to reduce absorption and improve the efficiency of color conversion. Background Art

[0004] Light emitting diodes (LEDs), such as micro-LEDs, mini-LEDs, and organic light emitting diodes (OLEDs), are used in a variety of applications. For example, the diodes can be used in display panels, such as mobile devices, portable computers, tablet computers, computer monitors, automotive displays, smart watches, and television displays, as well as in backlights and signage. These LEDs can be integrated with color conversion elements, such as quantum dot color converters (e.g., quantum dot color filters) to emit light of various colors, such as red and green light. For example, an LED can emit blue light, which excites red and green quantum dots to emit red and green light, respectively.

[0005] Information displays can be continuously refined to achieve higher optical efficiency, providing viewers with optimal brightness, color gamut, high contrast, and high resolution experience in a pixel-by-pixel format at low cost. Emissive displays can be based on quantum dot (QD) excitation from a light emitting diode (LED) array or an organic light emitting diode (OLED) array. Emissive displays all have many of the same optical efficiency requirements. Each layer of an emissive display contributes to the absorption, scattering, reflection, and transmission properties of the display.

[0006] Light at high output angles can be trapped inside the cover glass of a display due to, for example, total internal reflection (TIR). In displays utilizing quantum dots (e.g., quantum-sized particles of any shape, but often referred to as "dots"), the quantum dot layer re-emits light at a variety of angles, so that there can be a large amount of light that undergoes TIR. Light reflected back through TIR can be absorbed by a color filter or so-called black matrix material of a different or same color, resulting in a loss in the amount of light that is ultimately emitted by the display. Summary of the invention

[0007] Embodiments of the present disclosure relate to apparatus and methods related to color conversion devices that increase the efficiency and amount of light emitted from the device. In order to improve the efficiency of the display, it is desirable to increase the amount of light emitted from each of the color cells at a lower angle, for example by "recycling" and redirecting light at a higher angle. In this regard, the apparatus includes a color cell, the color cell including: a color conversion matrix having a plurality of quantum dots suspended in the matrix; a layer of low refractive index material positioned adjacent to the color conversion matrix; and a color filter positioned adjacent to the layer of low refractive index material and opposite to the color conversion matrix. The color cell is defined by a plurality of walls (e.g., a first wall and a second wall). Each of the plurality of walls includes an absorptive portion and a reflective portion. The absorptive portion is positioned adjacent to the color filter, while the reflective portion is positioned adjacent to the color conversion matrix and the layer of low refractive index material. In this regard, the reflective portion causes any light incident thereon to be reflected back within the individual color cells, and the absorptive portion prevents ambient light from being reflected by the reflective portion and directs the light to escape through the color filter (as desired). When excited with the same amount of LED / OLED light, each color unit within the device emits approximately the same amount of light and produces a uniform output. The device further comprises a substrate extending between the plurality of walls, in particular between the absorbing portions. A light source for emitting light is positioned adjacent to the color unit between the plurality of walls, in particular the reflecting portions.

[0008] In an example embodiment, a device is provided. The device includes a color conversion unit. The color conversion unit includes a low refractive index material layer, a color filter disposed adjacent to the low refractive index material layer, and a color conversion matrix. The color conversion matrix includes a plurality of quantum dots and a dielectric. The color conversion matrix is ​​disposed adjacent to one of the color filter or the low refractive index material layer. The device further includes a first wall and a second wall, wherein the color conversion unit is defined between the first wall and the second wall. Each of the first wall and the second wall includes a reflective portion and an absorptive portion. The device further includes a first substrate, the first substrate being positioned adjacent to the color conversion unit and extending between the absorptive portion of the first wall and the second wall. The device further includes a second substrate, the second substrate being positioned adjacent to the color conversion matrix of the color conversion unit and extending between the reflective portion of the first wall and the reflective portion of the second wall.

[0009] In some embodiments, the absorbing portion may be a dark mirror. In some embodiments, the dark mirror may include an interference filter and an opaque metal layer. In some embodiments, the opaque metal layer may include chromium and chromium oxide or chromium oxynitride. In some embodiments, the opaque metal layer may be aluminum. In some embodiments, the absorbing portion may be a black polymer containing a black pigment. In some embodiments, the black pigment may be carbon black. In some embodiments, the absorbing portion may define a thickness of less than 300 nanometers. In some embodiments, the absorbing portion may be a metal dielectric structure.

[0010] In some embodiments, the reflective portion may include embedded particles. In some embodiments, the reflective portion may include a polymer including chemically coupled metal nanoparticles. In some embodiments, the reflective portion may include a reflective metal.

[0011] In some embodiments, the first wall may define a first wall thickness and the second wall may define a second wall thickness. Each of the first wall thickness and the second wall thickness may be approximately 10 microns.

[0012] In another example embodiment, a color conversion device is provided. The color conversion device includes a first color conversion unit and a second color conversion unit. The first color conversion unit includes a low refractive index material layer adjacent to a color filter. The first color conversion unit further includes a color conversion matrix, the color conversion matrix including a plurality of quantum dots and a medium, the color conversion matrix positioned adjacent to the low refractive index material layer or the color filter. The second color conversion unit includes: a diffusion matrix including a plurality of light scattering particles; and a second color filter disposed adjacent to the diffusion matrix. The color conversion device further includes a plurality of walls, each including a reflective portion and an absorptive portion. The first color conversion unit is defined between a first wall and a second wall, and the second color conversion unit is defined between the second wall and a third wall. The color conversion device further includes a first substrate positioned adjacent to the first color conversion unit and the second color conversion unit. The first substrate extends between the absorptive portion of the first wall and the third wall. The color conversion device further includes a second substrate positioned adjacent to the first color conversion unit and the second color conversion unit. The second substrate extends between the reflective portion of the first wall and the third wall.

[0013] In some embodiments, the absorbing portion may be a dark mirror. In some embodiments, the dark mirror may include an interference filter and an opaque metal layer. In some embodiments, the opaque metal layer may include chromium and chromium oxide or chromium oxynitride. In some embodiments, the opaque metal layer may be aluminum. In some embodiments, the absorbing portion may be a black polymer containing a black pigment. In some embodiments, the absorbing portion may define a thickness of less than 300 nanometers.

[0014] In some embodiments, the reflective portion may include embedded particles. In some embodiments, the reflective portion may include a polymer including chemically coupled metal nanoparticles. In some embodiments, the plurality of walls each define a wall thickness of about 10 microns.

[0015] In some embodiments, the color conversion device may further include a third color conversion unit. The third color conversion unit may include a third low refractive index material layer and a third color filter disposed adjacent to the third low refractive index material layer. The third color conversion unit may further include a third color conversion matrix, the third color conversion matrix including a third plurality of quantum dots and a third medium. The third color conversion matrix may be disposed adjacent to the third low refractive index material layer or the third color filter. The third color conversion unit may be defined by the third wall and the fourth wall. In some embodiments, the first substrate may extend to the absorbing portion of the fourth wall, and the second substrate may extend to the reflecting portion of the fourth wall.

[0016] In yet another example embodiment, a method of forming a color conversion device is provided. The method includes forming at least a first wall and a second wall on a first substrate, each of the first wall and the second wall including an absorptive portion and a reflective portion. The method further includes forming at least one color conversion unit on the first substrate between the first wall and the second wall. The at least one color conversion unit includes a low refractive index material layer adjacent to a color filter. The first color conversion unit further includes a photoresist layer positioned adjacent to the low refractive index material layer or the color filter. The method further includes fixing a second substrate to the reflective portion of each of the first wall and the second wall.

[0017] In some embodiments, the absorbing portion may be an interference filter and an opaque metal layer. In some embodiments, the absorbing portion may be a photomask. In some embodiments, the reflecting portion may be formed by photolithography. In some embodiments, the reflecting portion may include an electroplated polymer. In some embodiments, the reflecting portion may include a polymer mixed with metal particles. In some embodiments, the reflecting portion may include a polymer mixed with light scattering particles.

[0018] In yet another example embodiment, a display is provided. The display includes a color conversion unit. The color conversion unit includes a low refractive index material layer, a color filter disposed adjacent to the low refractive index material layer, and a color conversion matrix. The color conversion matrix includes a plurality of quantum dots and a medium. The color conversion matrix is ​​disposed adjacent to one of the color filter or the low refractive index material layer. The display further includes a first wall and a second wall, wherein the color conversion unit is defined between the first wall and the second wall. Each of the first wall and the second wall includes a reflective portion and an absorptive portion. The display further includes a first substrate extending between the absorptive portion of the first wall and the second wall. The device further includes a second substrate, wherein a light source extends between the reflective portion of the first wall and the reflective portion of the second wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Reference will now be made to the accompanying drawings which are not drawn to scale, in which:

[0020] Figure 1 shows example apparatus according to some examples discussed herein;

[0021] FIG. 2A to FIG. 2B shows a cross-sectional view of an example color conversion device according to some implementations discussed herein;

[0022] Figure 3 illustrates a cross-sectional view of another example color conversion device according to some implementations discussed herein;

[0023] Figure 4 to Figure 4B shows a graph depicting a simulated reflectance spectrum in air according to some embodiments discussed herein;

[0024] Figure 5 A flowchart illustrating an example method for forming a device according to some embodiments discussed herein;

[0025] Figure 6 A flow chart illustrating an example method of forming a wall according to some embodiments discussed herein;

[0026] Figure 7 a flow chart illustrating an example method of forming an absorbent portion of a wall according to some embodiments discussed herein; and

[0027] Figures 8 to 10 A flow chart illustrating an example method of forming a reflective portion of a wall according to some embodiments discussed herein. DETAILED DESCRIPTION

[0028] Some example embodiments will be described more fully herein without reference to the accompanying drawings, some but not all of which are shown in the accompanying drawings. Indeed, the examples described and depicted herein should not be construed as limiting the scope, applicability, or configuration of the present disclosure. Rather, these example embodiments are provided so that the present disclosure will satisfy applicable legal requirements. The same reference numerals refer to the same elements throughout.

[0029] Directional terms used herein, such as up, down, left, right, front, back, top, bottom, vertical, and horizontal, are made with reference only to the drawings drawn and are not intended to imply an absolute orientation.

[0030] Figure 1 1 shows a color conversion device 100 that includes a plurality of walls 119 disposed between a first substrate 105 and a second substrate 140. Each of the plurality of walls 119 includes an absorptive portion 110 and a reflective portion 115. The reflective portion 115 provides a highly reflective surface over a wide spectral range, such as within the visible wavelength. In some embodiments, the reflective portion 115 can allow for more efficient color conversion of incident blue photons compared to conventional color converters. Conversely, the absorptive portion 110 provides a dark portion to absorb light and prevent ambient light reflections and crosstalk between different color units (such as with respect to Figure 3 shown).

[0031] In some embodiments, the second substrate 140 can be adhered (e.g., laser welded, adhesively attached, etc.) to the surface of the wall 119. For example, the second substrate 140 can be connected to the reflective portion 115 of the wall 119 at the interface 123. In some embodiments, the second substrate 140 can include a light emitting element to emit light into a color conversion matrix 125, which includes a medium 127 and a plurality of light emitting emitter particles 126 (e.g., quantum dots). In some embodiments, the plurality of light emitting emitter particles can change the wavelength of the light, thereby changing the color of the light escaping from the top surface 104 of the first substrate 105. To improve the light distribution and coloration of the color conversion device, more layers can be added between the first substrate 105 and the second substrate 140 to improve light recycling and efficiency.

[0032] FIG. 2A to FIG. 2B A cross-sectional view of an example color conversion device 200, 200' is shown. The color conversion device 200, 200' can be part of a display device and can provide a color conversion function. The color conversion device 200, 200' may include a color conversion unit 245, 245' defined between a plurality of walls 219 (e.g., a first wall and a second wall) and defined by a first substrate 205 and a second substrate 240.

[0033] In some embodiments, the first substrate 205 can be configured to allow light to escape. In some embodiments, the first substrate can be a glass substrate comprising a glass material such as aluminosilicate, alkali aluminosilicate, borosilicate, alkali borosilicate, aluminoborosilicate, alkali aluminoborosilicate, soda lime, or other suitable glass. Non-limiting examples of commercially available glasses suitable for use as the first substrate 205 include LotusTM, IrisTM and CorningIncorporated Glass. In some embodiments, the first substrate 205 can have a refractive index in a range of, for example, between about 1.5 and 2.4. In some embodiments, the first substrate can have a substrate thickness in a range of, for example, between about 0.1 mm and about 2 mm.

[0034] In some embodiments, the second substrate 240 may include a reflective surface facing the color conversion matrix 225, and may include a light source. In this regard, the second substrate 240 may include metal electrodes for quantum dot OLED designs, or dichroic mirrors added to the second substrate 240. The reflective surface on the second substrate 240 may increase light recycling within the color conversion cells 245, 245', and thus may improve the efficiency of the color conversion device 200, 200'.

[0035] In some embodiments, the color conversion unit 245, 245' can convert blue light emitted from an LED or OLED into a desired color. The emission color can be determined by the type of light emitting emitter positioned within the color conversion unit 245, 245'. In this regard, different light emitting emitters can cause different reactions with blue light. In some embodiments, color-specific quantum dots can be used as light emitting emitters to change the emitted blue light to, for example, red or green. The color conversion unit 245, 245' may include one or more components to filter and increase the output of the desired color from the color conversion unit while preventing the emission of light waves of other colors.

[0036] The color conversion unit 245, 245' can include a color conversion matrix 225. The color conversion matrix 225 includes a plurality of quantum dots 226 suspended in a medium 227. In some embodiments, the color conversion matrix 225 can further include light scattering particles 228 suspended within the medium 227. As will be discussed herein, the light scattering particles 228 can increase the scattering of blue light emitted from the backplane emitter. In some embodiments, the medium is a polymer. In some embodiments, the color conversion matrix 225 can have a refractive index between about 1.4 and 2.2.

[0037] In some embodiments, other luminescent emitter particles may be used instead of quantum dots, such as phosphors, fluorophores, nanocrystals, or other suitable luminescent emitter particles.

[0038] In some embodiments, the color conversion unit 245 may include a color filter 220. The color filter 220 may define a first filter surface 220a and a second filter surface 220b, wherein the second filter surface 220b is opposite to the first filter surface 220b. Figure 2A As shown in , the first filter surface 220a can be adjacent to the first substrate 205. In some embodiments, such as Figure 2B , the second filter surface 220b can be adjacent to the color conversion matrix 225. The color filter 220 can extend between the plurality of walls 219. In some embodiments, the color filter 220 can have a filter thickness that can extend between both the absorptive portion 210 and the reflective portion 215 of the plurality of walls 219, while in other embodiments, the color filter 220 can extend only within the reflective portion 215 of the plurality of walls 219. In some embodiments, the color filter thickness can be between about 2 microns and about 10 microns.

[0039] Color filter 220 may correspond to the desired color output of color conversion unit 245, 245'. In this regard, a red color filter layer may be positioned over a red conversion matrix, a green color filter layer may be positioned over a green conversion matrix, and a blue color filter may be positioned over a blue conversion matrix. In some embodiments, color filter 220 may include a pigment or dye within a polymer to create a desired color.

[0040] In some embodiments, the color conversion unit 245, 245' may include a low refractive index material layer 235. The low refractive index material layer may be formed of any material, either uniform or nanostructured ("nano" means at a scale smaller than the wavelength of light, such that light sees it as a uniform medium with an average refractive index) that has an average refractive index lower than the average refractive index of display glass and common polymers, i.e., 1.5. Some example low refractive index materials may include, but are not limited to: uniform low refractive index materials with a refractive index in the range of 1.3 to 1.4, such as fluorinated polymers; porous materials with a closed pore structure in the range of 1.1 to 1.3, such as a polymer matrix containing hollow nanoparticles (e.g., hollow silica nanoparticles); structured (e.g., an array of nano-sized pillars with spaces (air) between them) or more commonly unstructured open pore structure materials, such as fumed silica (which can achieve a refractive index of n = 1.1) and aerogels (which can achieve a record low refractive index of n = 1.05 (90% porosity) and are very durable). The low refractive index material layer 235 may define a first surface 235a and a second surface 235b opposite to the first surface 235a. Figure 2A As shown in , the low refractive index material layer 235 can be disposed between the color filter 220 and the color conversion matrix 225 such that the first surface 235a abuts the second filter surface 220b and the second surface 235b abuts the color conversion matrix 225. In other embodiments, such as Figure 2B As shown in FIG. 2 , a layer 235 of low refractive index material may be disposed between the color filter 220 and the first substrate 205 such that a first surface 235a abuts the first substrate 205 and a second surface 235b abuts the first filter surface 220b.

[0041] In some embodiments, the low refractive index material layer 235 may have a refractive index of less than about 1.5. The low refractive index material layer 235 may have a layer thickness in the range of, for example, about 2 microns to about 10 microns. In some embodiments, the low refractive index material layer 235 may include a plurality of gas-filled (e.g., air-filled) holes sealed by the color conversion matrix 225. In some embodiments, the low refractive index material layer 235 may include an aerogel. In other embodiments, the low refractive index material layer 235 may include a mixture of hollow silica nanoparticles and a polymer binder. In some embodiments, the low refractive index material layer 235 may include a property that prevents the color conversion matrix 225 from filling in a porous surface. In other embodiments, the medium 227 of the color conversion matrix 225 may exhibit a large surface tension so that the color conversion matrix 225 does not penetrate the porous surface of the low refractive index material layer 235.

[0042] In some embodiments, the color conversion matrix 225 may be positioned adjacent to one of the low refractive index material 235 or the color filter 220. However, it may be beneficial for the second surface 235b of the low refractive index material layer 235 to be adjacent to the color conversion matrix 225 and the first surface 235a of the low refractive index material layer 235 to be adjacent to the second filter surface 220b of the color filter 220. In this regard, positioning the low refractive index material layer 235 adjacent to the color conversion matrix 225 reduces coupling losses, and in some cases may suppress any coupling losses. To explain, quantum dots emit light at all possible angles. Without including the low refractive index material layer 235, high angle light rays may experience total internal reflection (TIR) ​​at the glass-air boundary. The low refractive index material layer 235 adjacent to the color conversion matrix 225 causes the high angle light rays to be recycled within the color conversion matrix 225, where the high angle light rays may be converted into low angle light rays and can be output by the color conversion matrix 225. Further, when the color filter 220 is adjacent to the first substrate 205, the color filter 220 may cause a lower amount of ambient light to be reflected into the color conversion cells 245, 245' than when the low refractive index material layer 235 is adjacent to the first substrate 205. Therefore, when the low refractive index material layer 235 is adjacent to the color conversion matrix 225, the efficiency may be improved even more, such as Figure 2A As shown in .

[0043] Returning to the color conversion matrix 225, in some embodiments, the color conversion matrix 225 may further include scattering particles 228. The scattering particles 228 may be titanium dioxide (TiO2), niobium, hafnium, barium titanate, hollow silica, or other materials having a refractive index significantly higher or significantly lower than the refractive index of the medium 227. The scattering particles 228 may scatter the blue light emitted from the backplane emitter, thereby increasing the effective path length and allowing for increased absorption of the blue light at lower color conversion matrix 225 thickness or at lower concentrations of quantum dots 226 within the color conversion matrix 225.

[0044] Emission from quantum dots 226 within color conversion matrix 225 oriented at an angle below the critical angle for total internal reflection at the boundary with low index material layer 235 may enter low index material layer 235 and, while passing through low index material layer 235, enter color filter layer 220 and further into first substrate 205. The closer the refractive index of low index material layer 235 is to air, the higher percentage of emission will pass through first substrate 205 and into air. In the ultimate case where the refractive index of the low index material layer is 1.0 (e.g., an air gap is present), all light entering the low index material layer may pass through first substrate 205 without being trapped.

[0045] Emission from quantum dots 226 within color conversion matrix 225 above the critical angle for total internal reflection will be reflected back into color conversion matrix 225. The emission may be recycled within color conversion matrix 225 by undergoing scattering with the possibility of obtaining a more favorable ray trajectory, such that the emission may enter low refractive index material layer 235 on a second or third bounce, thereby resulting in higher optical efficiency for color conversion device 200.

[0046] To improve recycling within the color conversion cell 245 and the color conversion device 200, the plurality of walls 219 may be reflective to promote diffuse reflection (e.g., where the reflection has a spread in the reflected light angle). The diffuse nature of the reflection may further mix and absorb blue light from the backplane emitter (e.g., adjacent to and / or within the second substrate). The mixing may allow for a lower color conversion matrix 225 thickness or a lower concentration of quantum dots 226 within the color conversion matrix 225. The diffuse nature of the reflection from the reflective portion 215 of the plurality of walls 219 may also facilitate recycling of light TIR reflected from the low refractive index material layer 235, which in addition to the scattering particles 228, also works within the color conversion matrix 225 to change the light trajectory.

[0047] To increase recycling, each of the plurality of walls 219 includes a reflective portion 215 spanning color conversion matrix 225, low index material layer 235, and a portion of color filter 220. In this regard, reflective portion 215 may comprise a major portion of the surface area of ​​wall 219 facing color conversion cell 245.

[0048] The reflective portion 215 of the plurality of walls 219 can be formed using different components. In some embodiments, the reflective portion 215 includes a reflective metal disposed around the plurality of walls 219 , while in other embodiments, the reflective portion 215 extends within the plurality of walls 219 .

[0049] The plurality of walls may have a wall thickness. The wall thickness may desirably be large enough to prevent crosstalk between adjacent color conversion cells (see, e.g., Figure 3 The wall thickness "T RP ”), while being small enough to maximize the effective area of ​​color conversion unit 245. In some embodiments, the wall thickness can be between 5 microns and 100 microns. In some embodiments, the wall thickness can be about 10 microns.

[0050] In an embodiment, the reflective portion 215 of the plurality of walls 219 may include a polymer material filled with light scattering particles. In this regard, the light scattering particles may have a refractive index different from the refractive index of the polymer. The polymer may have a refractive index between about 1.41 and about 1.6. In some embodiments, the light scattering particles may have a refractive index significantly higher than that of the polymer, for example, the light scattering particles may have a refractive index between about 2.2 and 2.8. Example light scattering particles may be titanium dioxide (TiO2), zirconium dioxide (ZrO2), barium titanate (BaTiO3), or similar compounds. In some embodiments, the reflective portion 215 of the plurality of walls 219 may include up to 40% by weight of light scattering particles and may have a reflectivity of about 79% at a thickness of 20 microns.

[0051] In other embodiments, the light scattering particles may have a refractive index significantly lower than that of the polymer, such as hollow glass particles, which may have a refractive index of approximately 1.5.

[0052] In some embodiments, the reflective portions 215 of the plurality of walls 219 can be photoimageable, and thus, a photolithography tool can be used to pattern the plurality of walls 219 .

[0053] In some embodiments, the polymer may be a resin. In this regard, in some embodiments, the UV or thermally cured resin may be filled with light scattering particles. In some embodiments, micro-imprinting may be used to pattern and position the plurality of walls 219. However, etching may be required to remove any residual resin layer positioned on the second substrate 240.

[0054] In another example embodiment, the reflective portion 215 of the plurality of walls 219 may be formed of a polymer material filled with metal particles. In some embodiments, inks filled with metal may be used to create the desired reflectivity, such as vacuum metal pigments such as Sun Chemical's Brenda-Lutz SPLENDAL or Schlenk's Decomet. In some embodiments, the polymer filled with metal particles may be compatible with 3D printing and / or other printable electronics applications. In some embodiments, the metal particles may be silver or aluminum nanoparticles. In some embodiments, photolithography may be used with the polymer filled with metal particles to form the reflective portion 215 of the plurality of walls 219.

[0055] In another example embodiment, the plurality of walls 219 may be formed of a polymer material, wherein silver nanoparticles have been precipitated in the volume of the polymer upon illumination and assembled into a highly reflective layer at the surface of the plurality of walls 219 .

[0056] In another example embodiment, the plurality of walls 219 may be formed by coating a polymer wall with a thin layer of a reflective layer. In some embodiments, the polymer may be a 3D printable polymer that is receptive to chemical plating. In some embodiments, a thin coating of metallic silver (or other highly reflective metal layer) may be applied to the polymer wall formed by photolithography by chemical plating. Alternatively, in some embodiments, functionalized metal nanoparticles or metal oxide nanoparticles may be chemically coupled (e.g., EDC coupled) to the polymer wall (e.g., polymer alone, polymer filled with metal particles, polymer filled with light scattering particles, etc.).

[0057] It is worth noting that in some embodiments, it is undesirable for the reflective portion to directly contact the first substrate due to ambient light reflection on the surface. To prevent ambient light reflection, each of the plurality of walls 219 includes an absorbing portion 210. The absorbing portion 210 acts as a light shielding layer. In some embodiments, the absorbing portion 210 can appear black. In some embodiments, the absorbing portion 210 can be thin. In this regard, the absorbing portion 210 only spans a smaller portion of the color filter 220.

[0058] In some embodiments, the absorptive portion 210 can have a reflectivity of less than 10%, less than 5%, or even less than 1%.

[0059] In some embodiments, the absorption portion 210 can be a black matrix formed of a black photoresist material, such as a photopolymer containing carbon black and / or manganese oxide. However, many black photoresist materials may require a thickness of several microns to achieve the desired light flickering characteristics, which in turn reduces the size of the reflective portion 215, thereby reducing the amount of recycling.

[0060] In other embodiments, the absorbing portion 210 may be formed by a dark mirror deposited and patterned on the first substrate 205. In some embodiments, the dark mirror may have a thickness of less than 300 nanometers. In some embodiments, the absorbing portion 210 may include an interference filter and an opaque metal layer. The interference filter may be configured to nullify any reflections from the opaque metal layer. An example dark mirror is a metal dielectric single cavity structure or a metal dielectric double cavity structure using chromium and chromium oxide or chromium oxynitride. In a further example, the dark mirror may be formed by a combination of a black matrix resist and physical vapor deposition containing a metal layer or a combination of a metal and a dielectric layer.

[0061] Other example configurations of dark mirrors may be similar to those used in photomasks for semiconductors and optical apertures for optical systems. In some embodiments, the dark mirror may be formed using physical vapor deposition. In some embodiments, a black chrome mirror such as used in photomasks for semiconductors may be used, while in other embodiments, aluminum metal with a dual cavity dark mirror using silicon monoxide (SiO), silicon dioxide (SiO2), or aluminum oxide (Al2O3) may be used as a dielectric with a thin chrome reflector.

[0062] In another example embodiment, the absorbing portion 210 may be formed of tungsten. In yet another example embodiment, the absorbing portion 210 may be formed of an evaporated layer of a metal dielectric alloy. In yet another embodiment, the absorbing portion 210 may be formed of a hydrogenated germanium silicon alloy.

[0063] In some embodiments, the exposed metal portion can be used as a seed layer for electrolysis or electroplating to form the reflective portion 215 of the plurality of walls 219. In other embodiments, an additional metal layer can be deposited on top of the dark mirror, where the additional metal layer is compatible with the reflective portion 215. For example, an Al opaque layer in a black aluminum dark mirror can be used for aluminum plating, or a dark mirror can be formed with a nickel reflector and the nickel used as a seed for chemically deposited nickel.

[0064] To form a display, more than one color conversion device 200 may be positioned adjacent to each of the color conversion cells sharing one or more of the plurality of walls. Figure 3 A color conversion device 300 is shown including three color cells. Each of the three color cells may be separated by a corresponding wall and defined between a first substrate 205 and a second substrate 240. Although described herein as a first color cell 245a, a second color cell 245b, and a third color cell 245c, the order of the color cells is interchangeable and may be patterned depending on the desired results.

[0065] In some embodiments, the first color unit 245a may include a diffusion matrix 229 including a plurality of light scattering particles 228. In some embodiments, the diffusion matrix 229 may include a polymer having inclusions. In some embodiments, the first color unit 245a may further include a first color filter 220a disposed above the diffusion matrix 229. In some embodiments, the first color unit 245a may be configured to discharge blue light. In this regard, quantum dots or other light emitting emitters are not required to change the color of the emitted light (e.g., the LED may be a blue light LED). However, the light scattering particles 228 may diffuse the light so that the emitted light is consistent with the light emitted from the second color unit 245b and the third color unit 245c because the red and green quantum dots may be highly scattered.

[0066] In some embodiments, each of the second color unit 245b and the third color conversion unit 245c can reflect the structure of the color conversion device 200 as discussed with reference to Figure 2. However, the second color unit 245b can include a color conversion matrix including first color quantum dots (e.g., red) and corresponding color filters 220b, and the third color unit 245c can include second color quantum dots (e.g., green) and corresponding color filters 220c.

[0067] As discussed, the absorptive portions 210 of the plurality of walls 219 prevent ambient light from reflecting into the color cells. In some embodiments, as shown, the absorptive portions 210 can additionally prevent crosstalk between color cells (e.g., the first color cell 245a and the second color cell 245b, or the second color cell 245b and the third color cell 245c).

[0068] FIG. 4A to FIG. 4B The reflectivity percentage in air through a glass substrate (eg, first substrate) coated with the absorbing portion 210 is shown for light of different wavelengths within an incident angle range of 0° to 60°. Figure 4A A black aluminum dark mirror coating is shown as the absorbing part, and Figure 4B As shown, the dual cavity black chrome coating produces lower reflectivity over a wide wavelength range regardless of the incident angle, while the black aluminum dark mirror provides low reflectivity at certain incident angles between about 400nm and 600nm wavelengths.

[0069] Example Flowchart

[0070] Figure 5 4 is a flow chart illustrating an example method 400 for forming a color conversion device according to some embodiments discussed herein. At operation 402, a plurality of walls are formed on a first substrate. At operation 404, a color filter is formed on the first substrate between the plurality of walls. At operation 406, a layer of low refractive index material is formed on the color filter. At operation 408, a light emitting layer (e.g., having light emitting emitter particles) is formed on the layer of low refractive index material. At operation 410, a second substrate is laminated to the plurality of walls. Additional steps not shown may be included, such as forming an encapsulation layer to protect the light emitting layer, another encapsulation layer to protect the OLED emitter, a planarization layer, or an adhesive layer for lamination.

[0071] Figures 6 to 10 is an example flow chart for forming part of a color conversion device. Figure 6 is a diagram showing a method for forming a plurality of walls. Figure 5 4. At operation 412, an absorptive portion of the wall is formed. At operation 414, a reflective portion of the wall is formed on the absorptive portion. Figure 7is a diagram showing the absorbent portion used to form the wall Figure 6 4. At operation 416, an absorbing material is patterned onto the first substrate. In some embodiments, the absorbing material can be patterned by photolithography, 3D printing, coating, or other application. Optionally, at operation 418, an additional seed layer can be deposited onto the absorbing material. Operation 418 can be utilized when the absorbing portion is incompatible with the reflective portion.

[0072] Figures 8 to 10 is a flow chart illustrating operation 414 for forming a reflective portion of a wall. Figure 8 A first method 414' of forming a reflective portion is shown. At operation 420, a polymer is mixed with light scattering particles. At operation 422, the mixture of polymer and light scattering particles is applied to the absorbing portion by photolithography. In some embodiments, photolithography can pattern the application of the mixture, while in other embodiments, photolithography can coat the mixture onto the absorbing portion. Optionally, at operation 424, the residual mixture can be etched away or otherwise removed from the undesirable portion.

[0073] Fig. 9 Another method of forming a reflective portion is shown in 414. At operation 430, a polymer is mixed with metal particles. At operation 432, the mixture of polymer and metal particles is applied to the absorbing portion by photolithography. In some embodiments, the photolithography may pattern the application of the mixture, while in other embodiments, the photolithography may coat the mixture onto the absorbing portion. Optionally, at operation 434, the residual mixture may be etched away or otherwise removed from the undesirable portion.

[0074] Fig.10 Another method 414'' of forming a reflective portion is shown. At operation 440, a base of a wall is formed on the absorptive portion. In some embodiments, the base may be a polymer or other printable material. At operation 442, reflective nanoparticles are applied to the base.

[0075] It is worth noting that Figures 6 to 10 Although the above operations are described in a certain order, they may be performed in a different order and / or some of the operations may be performed simultaneously.

[0076] in conclusion

[0077] Therefore, it will be readily understood by those skilled in the art that the present disclosure is susceptible to widespread utility and application. Without departing from the essence or scope of the present disclosure, many embodiments and adaptations of the present disclosure other than those described herein and many variations, modifications and equivalent arrangements will be apparent or reasonably suggested from the present disclosure and the foregoing description thereof. Therefore, although the present disclosure has been described in detail herein with respect to its preferred embodiments, it should be understood that the present disclosure is merely illustrative and exemplary and does not exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements.

Claims

1. A device comprising: Color conversion unit, including: a layer of low refractive index material; a color filter disposed adjacent to the low refractive index material layer; and a color conversion matrix comprising a plurality of quantum dots and a dielectric, wherein the color conversion matrix is ​​adjacent to one of the low refractive index material layer or the color filter; a first wall and a second wall, wherein each of the first wall and the second wall comprises a reflective portion and an absorptive portion, and wherein the color conversion unit is defined between the first wall and the second wall; a first substrate positioned adjacent to the color conversion cell, wherein the first substrate extends between the absorbing portion of the first wall and the absorbing portion of the second wall; and A second substrate is positioned adjacent to the color conversion matrix of the color conversion cell, wherein the second substrate extends between the reflective portion of the first wall and the reflective portion of the second wall.

2. The device of claim 1, wherein the absorbing portion comprises a dark mirror.

3. The apparatus of claim 2, wherein the dark mirror comprises an interference filter and an opaque metal layer.

4. The device of claim 3, wherein the opaque metal layer comprises chromium and chromium oxide or chromium oxynitride.

5. The device of claim 3, wherein the opaque metal layer comprises aluminum.

6. The device of claim 1, wherein the absorbing portion comprises a black polymer containing a black pigment.

7. The apparatus of claim 6, wherein the black pigment comprises carbon black.

8. The device of any one of claims 1 to 7, wherein the absorbing portion defines a thickness of less than 300 nanometers.

9. The device of any one of claims 1 to 8, wherein the absorbing portion comprises a metal dielectric structure.

10. The device of any one of claims 1 to 9, wherein the reflective portion comprises embedded particles.

11. The device of any one of claims 1 to 9, wherein the reflective portion comprises a polymer comprising chemically coupled metal nanoparticles.

12. The apparatus of any one of claims 1 to 9, wherein the reflective portion comprises a reflective metal.

13. The apparatus of any one of claims 1 to 12, wherein the first wall defines a first wall thickness and the second wall defines a second wall thickness, wherein the first wall thickness and the second wall thickness are approximately 10 microns.

14. A color conversion device comprising: The first color conversion unit comprises: a layer of low refractive index material; a color filter disposed adjacent to the low refractive index material layer; and a color conversion matrix comprising a plurality of quantum dots and a dielectric, wherein the color conversion matrix is ​​adjacent to one of the low refractive index material layer or the color filter; The second color conversion unit comprises: a diffusion matrix comprising a plurality of light scattering particles; and a second color filter disposed adjacent to the diffusion matrix; a plurality of walls, wherein each of the plurality of walls comprises a reflective portion and an absorptive portion, wherein the first color conversion unit is defined between a first wall and a second wall, and the second color conversion unit is defined between the second wall and a third wall; a first substrate positioned adjacent to the first color conversion cell and the second color conversion cell, wherein the first substrate extends between the absorbing portion of the first wall and the absorbing portion of the third wall; and A second substrate is positioned adjacent to the first color conversion cell and the second color conversion cell, wherein the second substrate extends between the reflective portion of the first wall and the reflective portion of the third wall.

15. The color conversion device of claim 14, wherein the absorbing portion comprises a dark mirror.

16. The color conversion device of claim 15, wherein the dark mirror comprises an interference filter and an opaque metal layer.

17. The color conversion device of claim 16, wherein the opaque metal layer comprises chromium and chromium oxide or chromium oxynitride.

18. The color conversion device of claim 14, wherein the absorbing portion comprises a black polymer containing a black pigment.

19. The color conversion device of any one of claims 14 to 18, wherein the absorbing portion defines a thickness of less than 300 nanometers.

20. A color conversion device as claimed in any one of claims 14 to 19, wherein the reflective portion comprises embedded particles.

21. A color conversion device as claimed in any one of claims 14 to 20, wherein the reflective portion comprises a polymer comprising chemically coupled metal nanoparticles.

22. The color conversion device of any one of claims 14 to 21, wherein the plurality of walls each define a wall thickness, and wherein the wall thickness is about 10 microns.

23. The color conversion device according to any one of claims 14 to 22, further comprising: A third color conversion unit, the third color conversion unit comprising: a second low refractive index material layer; a third color filter adjacent to the second low refractive index material layer; and a third color conversion matrix comprising a third plurality of quantum dots and a second medium, wherein the third color conversion matrix is ​​disposed adjacent to one of the second low refractive index material layer or the third color filter; wherein the third color conversion unit is defined by the third wall and the fourth wall, and wherein the first substrate extends to the absorbing portion of the fourth wall, and Wherein the second substrate extends to the reflective portion of the fourth wall.

24. A method of forming a color conversion device, the method comprising: forming at least a first wall and a second wall on a first substrate, each of the first wall and the second wall comprising an absorptive portion and a reflective portion; At least one color conversion unit is formed on the first substrate between the first wall and the second wall, the at least one color conversion unit comprising: a layer of low refractive index material; a color filter adjacent to the layer of low refractive index material; and a photoresist layer positioned adjacent to one of the low refractive index material layer or the color filter; and A second substrate is secured to the reflective portion of each of the first wall and the second wall.

25. The method of claim 24, wherein the absorbing portion comprises an interference filter and an opaque metal layer.

26. The method of claim 24, wherein the absorbing portion comprises a photomask.

27. The method of any one of claims 24 to 26, wherein the reflective portion is formed by photolithography.

28. The method of any one of claims 24 to 26, wherein the reflective portion comprises an electroplated polymer.

29. A method as claimed in any one of claims 24 to 26, wherein the reflective portion comprises a polymer mixed with metal particles.

30. A method as claimed in any one of claims 24 to 26, wherein the reflective portion comprises a polymer mixed with light scattering particles.

31. A display comprising: Color units, including: a layer of low refractive index material; a color filter adjacent to the layer of low refractive index material; and a color conversion matrix comprising a plurality of quantum dots and a dielectric, wherein the color conversion is adjacent to one of the low refractive index material layer or the color filter; a first wall and a second wall, wherein each of the first wall and the second wall includes a reflective portion and an absorptive portion, and wherein the color unit is defined between the first wall and the second wall; a first substrate positioned adjacent to the color unit, wherein the first substrate extends between the absorptive portion of the first wall and the absorptive portion of the second wall; and A second substrate is positioned adjacent the color conversion matrix of the color cells, wherein a light source extends between the reflective portion of the first wall and the reflective portion of the second wall.

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