Phosphor-converted Light-emitting Diode (LED) color tuning

Abstract

A light source including a plurality of light emitting diodes (LEDs) includes a primary device material and a laser modified device material to achieve a tailored color point distribution. The device material may be a downconverter material and / or a functional material. The tailored color point distribution includes improved color yield by modifying a section of the device material of the LED that distorts the reference color point distribution. Other tailored color point distributions include modifications to a section of the device material to provide a center of gravity of the tailored color distribution relative to the center of gravity of the reference color distribution. The modifications to the device material may be performed by femtosecond laser irradiation. The modifications to the downconverter material may include ablation for thickness reduction, and / or roughening for surface topography change, and / or three-dimensional shaping for emission tunability. The modifications to the functional material may include ablation for thickness reduction.

Description

[Technical Field]

[0001]

[0002] Embodiments of the present disclosure generally relate to light sources including light-emitting diodes (LEDs) and methods for making the same. More specifically, embodiments are directed to light sources comprising one or more light emitters including device materials, e.g., downconverter materials and / or functional materials, where the primary device material and the laser-modified device material are present. The primary device materials, e.g., the primary downconverter material and / or the primary functional material, are laser-treated to prepare the laser-modified device material, e.g., the laser-modified downconverter material and / or the laser-modified functional material. The light source as a whole comprises a tuned color point distribution. The tuned color point distribution can be tuned spectral characteristics of v' versus u' and / or tuned correlated color temperature. [Background technology]

[0002] Semiconductor light emitting devices or optical power emitting devices (such as devices that emit ultraviolet (UV) or infrared (IR) optical power), including light emitting diodes, resonant cavity light emitting diodes, vertical cavity laser diodes, and edge-emitting lasers, are among the most efficient light sources currently available. Semiconductor light emitting devices or optical power emitting devices (referred to herein for simplicity as LEDs) are attractive candidates for light sources such as camera flashes for handheld battery-powered devices such as cameras and mobile phones due to their compact size and lower power requirements. They may also be used in other applications such as automotive lighting, video torches, and general lighting, including home, store, office, and studio lighting, theater / stage lighting, and architectural lighting.

[0003] High-intensity / high-brightness light-emitting devices operable across the visible spectrum include III-V semiconductors, particularly binary, ternary, and quaternary alloys of gallium, aluminum, indium, and nitrogen, also referred to as III-nitride materials. III-nitride light-emitting devices are typically fabricated by epitaxially growing a stack of semiconductor layers of different compositions and dopant concentrations on a growth substrate, such as sapphire, silicon carbide, III-nitride, or other suitable substrate, by metalorganic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), or other epitaxial techniques. Sapphire is often used as the growth substrate because of its widespread commercial availability and relative ease of use. The stack grown on the growth substrate typically includes one or more n-type layers, e.g., doped with Si, formed on the substrate; a light-emitting or active region formed on the one or more n-type layers; and one or more p-type layers, e.g., doped with Mg, formed on the active region.

[0004] Phosphor-converted LEDs (pc-LEDs) contain a phosphor layer on the LED pump or die. The phosphor layer absorbs energy and converts the incident wavelength to a lower energy wavelength. For example, the phosphor layer downconverts high-energy LED light to a more desirable color spectrum. In practice, the composition and structure of the phosphor layer are selected to meet desired performance criteria. The color accuracy and distribution of the LED affect both color and luminous flux utilization.

[0005] The exact color point is an attribute of a pc-LED. In the LED industry, color spaces are divided into narrow color bins, such as the MacAdam Ellipses for lighting or the H color bin for automobile front lights. For example, the CIE 1931 and CIE 1976 chromaticity diagrams define color bins. CIE 1931 uses coordinates (x,y), while CIE 1976 uses coordinates (u',v'). If a light source is governed by a specific color bin, only LED-based devices within the specified color bin are usable.

[0006] Color spatial distribution is another topic for LED manufacturers. LED light is typically projected through secondary optics, which image the color distribution from the LED source onto the projection surface. Therefore, any non-uniformity in the color distribution of the LED source will appear as different colors in the projected image. This issue arises with microLEDs, where the small pixel size makes it difficult to maintain color uniformity between pixels.

[0007] Therefore, improving the color accuracy and color distribution of LEDs and micro-LEDs is an ongoing goal for LED manufacturers due to its impact on both color and luminous flux utilization. Summary of the Invention

[0008] Provided herein are light sources and methods for manufacturing the same.

[0009] In one embodiment, the light source includes a plurality of light emitting diodes (LEDs), a plurality of sections of primary downconverter material corresponding to a first plurality of LEDs, one or more sections of laser-modified downconverter material corresponding to a second plurality of LEDs, a light-blocking layer positioned between all of the LEDs, and a tailored color point distribution of the light source as a whole.

[0010] Another aspect provides a light source comprising: a monolithic body comprising a plurality of micro light emitting diodes (uLEDs), the uLEDs having at least one characteristic dimension of 1 micrometer to 300 micrometers, the characteristic dimension selected from the group consisting of height, width, depth, thickness, and combinations thereof; a continuous downconverter layer over all of the uLEDs, the continuous downconverter layer comprising a plurality of sections of primary downconverter material corresponding to a first plurality of uLEDs and one or more sections of laser-modified downconverter material corresponding to a second plurality of uLEDs, the one or more sections of laser-modified downconverter material comprising a reduced thickness, and / or a changed surface topography, and / or a three-dimensional shaping compared to the primary downconverter material; a light-blocking layer positioned between all of the uLEDs; and a tailored color point distribution of the light source as a whole.

[0011] In a further aspect, a method for manufacturing a light source comprising a plurality of light emitters includes measuring a reference color point distribution of a reference light source comprising a plurality of light emitting diodes (LEDs) and a primary downconverter material in the absence of the laser-modified downconverter material; preparing a reference color point distribution graph; identifying one or more sections of the primary downconverter material in which the corresponding LEDs contribute to a deviation from the adjusted color point distribution; and applying a laser treatment to the one or more sections of the primary downconverter material in which the corresponding LEDs contribute to a deviation from the adjusted color point distribution to prepare the one or more sections of the laser-modified downconverter material, thereby preparing a light source having the adjusted color point distribution.

[0012] Another embodiment is a light source that includes one or more light emitting diodes (LEDs), a primary downconverter material on the one or more LEDs, and a roughened downconverter material on the one or more LEDs.

[0013] A further aspect is a method of manufacturing a light source, comprising the steps of measuring a reference color point distribution of a reference light source comprising one or more light emitting diodes (LEDs) and a primary downconverter material in the absence of the laser-modified downconverter material; preparing a reference color point distribution graph; identifying one or more sections of the primary downconverter material in which the corresponding LEDs contribute to deviations from the adjusted color point distribution; and applying a roughening laser treatment to the one or more sections of the primary downconverter material in which the corresponding LEDs contribute to deviations from the adjusted color point distribution to prepare the one or more sections of the roughened downconverter material, thereby preparing a light source having the adjusted color point distribution.

[0014] In a further aspect, the light source comprises one or more light emitting diodes (LEDs) separated by a light blocking layer, a downconverter material on the one or more LEDs, and a functional material laser patterned on the downconverter material.

[0015] Another aspect provides a light source that includes one or more light emitting diodes (LEDs), a phosphor material that includes a polycrystalline ceramic plate offset onto the one or more LEDs, and a functional material laser patterned onto the phosphor material.

[0016] A further method of manufacturing a light source includes patterning functional materials of the light source, which include one or more light emitting diodes and a phosphor material.

[0017] In one embodiment, the light source includes a plurality of light emitting diodes (LEDs), a downconverter material on the LEDs, a plurality of sections of primary functional material corresponding to a first plurality of LEDs, one or more sections of ablated functional material corresponding to a second plurality of LEDs, a light blocking layer positioned between all of the LEDs, and a tailored color point distribution of the light source as a whole.

[0018] Another aspect is a method for manufacturing a light source including a plurality of light emitters, the method including steps of measuring a reference color point distribution of a reference light source including a plurality of light emitting diodes (LEDs), a downconverter material, and a primary functional material in the absence of the laser-modified functional material; preparing a reference color point distribution graph; identifying one or more sections of the primary functional material in which the corresponding LEDs contribute to a deviation from the adjusted color point distribution; and applying laser treatment to the one or more sections of the primary functional material in which the corresponding LEDs contribute to a deviation from the adjusted color point distribution to prepare the one or more sections of the laser-modified functional material, thereby preparing a light source having the adjusted color point distribution. [Brief explanation of the drawings]

[0019] In order that the above-mentioned features of the present disclosure may be understood in detail, a more particular description of the present disclosure briefly summarized above can be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only typical embodiments of the present disclosure and therefore should not be considered as limiting the scope of the present disclosure, as the present disclosure may admit of other equally effective embodiments. The embodiments described herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to like elements. The schematic diagrams herein are not to scale.

[0020] [Figure 1] FIG. 1 is a schematic plan view of a reference (or comparison) light source (unmodified). [Figure 2] 2 is an exemplary graph of the color points of pixels of illuminants that collectively represent the color point distributions of FIG. 1 shown for automotive color bins in CIE 1976 color space. [Figure 3] 1 is a schematic top view of a light source according to one or more embodiments. [Figure 4] 4 is an exemplary graph of color points for pixels of illuminants that collectively represent the color point distributions of FIGS. 3A and 3B for automotive color bins in CIE 1976 color space, in accordance with one or more embodiments. [Figure 5A] 1 is a schematic top view of an exemplary pattern for modifying a reference light source, according to one embodiment. [Figure 5B] FIG. 10 is a schematic top view of another exemplary pattern for modifying a reference light source, according to one embodiment. [Figure 6] 1 is a schematic cross-sectional view of a light source including a group of light emitting diodes (LEDs) including a primary downconverter material and a laser-modified downconverter material according to one or more embodiments. [Figure 7] 1 is a schematic cross-sectional view of a light source including a group of light emitting diodes (LEDs) including a primary functional material and a laser-modified functional material, according to one or more embodiments. [Figure 8] 1 is a schematic cross-sectional view of a light source comprising an array of light emitting diodes (LEDs) on a device substrate comprising a primary downconverter material and a laser-modified downconverter material according to one or more embodiments. [Figure 9] 1 is a schematic cross-sectional view of a light source comprising an array of light emitting diodes (LEDs) on a device substrate comprising a primary material and a laser-modified functional material according to one or more embodiments. [Figure 10] 1 is a schematic cross-sectional view of a light source comprising an array of micro light emitting diodes (uLEDs) on a device substrate comprising a primary downconverter material and a laser-modified downconverter material, according to one or more embodiments. [Figure 11] 1 is a schematic cross-sectional view of a light source comprising an array of micro light emitting diodes (uLEDs) on a device substrate comprising a primary material and a laser-modified functional material, according to one or more embodiments. [Figure 12] 1 is an exemplary graph of color point distribution in CIE 1976 color space with the centroids of automotive color bins for a reference illuminant and a target or desired illuminant, respectively. [Figure 13] 1 is an exemplary graph of color point distributions, each with a center of gravity for an adjusted illuminant and a target or desired illuminant, for an automotive color bin in CIE 1976 color space. [Figure 14A] 1 is a cross-sectional view of a light source including one or more light emitting diodes (LEDs) according to an embodiment. [Figure 14B] 1 is a cross-sectional view of a light source including one or more light emitting diodes (LEDs) according to an embodiment. [Figure 15A] 1 is a schematic cross-sectional view of light sources each including one or more light emitting diodes (LEDs) according to an embodiment. [Figure 15B] 1 is a schematic cross-sectional view of light sources each including one or more light emitting diodes (LEDs) according to an embodiment. [Figure 16A] 1 is a schematic cross-sectional view of light sources each including one or more light emitting diodes (LEDs) according to an embodiment. [Figure 16B] 1 is a schematic cross-sectional view of light sources each including one or more light emitting diodes (LEDs) according to an embodiment. [Figure 17] 1 is a schematic cross-sectional view of a light source including one or more light emitting diodes (LEDs) according to an embodiment. [Figure 18A] 1 is a schematic cross-sectional view of light sources each including one or more light emitting diodes (LEDs) according to an embodiment. [Figure 18B] 1 is a schematic cross-sectional view of light sources each including one or more light emitting diodes (LEDs) according to an embodiment. [Figure 19] FIG. 1 is a process flow diagram of a method for manufacturing a light source according to one or more embodiments. [Figure 20] 1 is a schematic diagram of an exemplary lighting system including LEDs according to embodiments herein. DETAILED DESCRIPTION OF THE INVENTION

[0021] Before describing several example embodiments of the present disclosure, it is to be understood that the present disclosure is not limited to the details of construction or process steps set forth in the following description. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways.

[0022] The term "substrate," as used herein in accordance with one or more embodiments, refers to an intermediate or final structure having a surface or portion of a surface upon which a process acts. Additionally, references to a substrate in some embodiments refer to only a portion of the substrate unless the context clearly indicates otherwise. Furthermore, references to deposition on a substrate in accordance with some embodiments include deposition on a bare substrate or deposition on a substrate having one or more films or features or materials deposited or formed thereon.

[0023] In one or more embodiments, "substrate" refers to any substrate or material surface formed on a substrate on which film processing occurs during the manufacturing process. A "growth substrate" or "LED substrate" is a substrate on which epitaxial layers, including one or more active layers, are prepared or grown. A "device substrate" is the substrate of the final product or device. In some embodiments, the growth substrate is removed and no additional substrate is included. In some embodiments, the growth substrate is removed and a device substrate is attached. In some embodiments, the "LED substrate" is included in an LED pump attached to the device substrate. In exemplary embodiments, the substrate surface on which processing occurs includes materials such as silicon, silicon oxide, silicon-on-insulator (SOI), strained silicon, amorphous silicon, doped silicon, carbon-doped silicon oxide, germanium, gallium arsenide, glass, sapphire, and any other suitable material, such as metals, metal nitrides, III-nitrides (e.g., GaN, AlN, InN, and alloys), metal alloys, and other conductive materials, depending on the application. Substrates include light-emitting diode (LED) devices, including, but not limited to, uLED devices. In some embodiments, the substrate is exposed to a pretreatment process to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure, and / or bake the substrate surface. In addition to film treatment directly on the surface of the substrate itself, in some embodiments, any of the disclosed film treatment steps are also performed on an underlying layer formed on the substrate, and the term "substrate surface" is intended to include such underlying layers, as the context indicates. Thus, for example, when a film / layer or partial film / layer is deposited on a substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0024] References to LEDs herein refer to light-emitting diodes that emit light when an electric current flows through them. In one or more embodiments, LEDs herein have one or more characteristic dimensions (e.g., height, width, depth, thickness, etc.) in the range of 75 micrometers to 300 micrometers. In one or more embodiments, one or more of the height, width, depth, and thickness dimensions have a value in the range of 100 to 300 micrometers. References to micrometers herein allow for a variation of ±1 to 5%. In preferred embodiments, one or more of the height, width, depth, and thickness dimensions have a value of 200 micrometers ±1 to 5%. In some examples, LEDs are referred to as microLEDs (uLEDs or μLEDs), which refer to LEDs having one or more characteristic dimensions (e.g., height, depth, thickness, etc.) on the order of micrometers or tens of micrometers. In one or more embodiments, one or more of the height, width, depth, and thickness dimensions have a value in the range of 1 to less than 75 micrometers, e.g., 1 to 50 micrometers, or 1 to 25 micrometers. Overall, in one or more embodiments, the LEDs herein can have characteristic dimensions in the range of 1 micrometer to 300 micrometers, and all values ​​and subranges therebetween.

[0025] Methods for depositing materials, layers, and thin films include, but are not limited to, sputter deposition, atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma-enhanced atomic layer deposition (PEALD), plasma-enhanced chemical vapor deposition (PECVD), and combinations thereof.

[0026] Methods for forming or growing the semiconductor layers, including the N-type layer, active region, and P-type layer, are formed according to methods known in the art. In one or more embodiments, the semiconductor layers are formed by epitaxial (EPI) growth. The semiconductor layers, according to one or more embodiments, include epitaxial layers, III-nitride layers, or epitaxial III-nitride layers. In one or more embodiments, the semiconductor layers include III-nitride materials, and in particular embodiments, epitaxial III-nitride materials. In some embodiments, the III-nitride materials include one or more of gallium (Ga), aluminum (Al), and indium (In). Thus, in some embodiments, the semiconductor layers include one or more of gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), indium aluminum nitride (InAlN), aluminum indium gallium nitride (AlInGaN), etc. The III-nitride material may be doped with one or more of silicon (Si), oxygen (O), boron (B), phosphorus (P), germanium (Ge), manganese (Mn), or magnesium (Mg), depending on whether a p-type or n-type III-nitride material is desired. In one or more embodiments, the semiconductor layer has a total thickness ranging from about 2 μm to about 10 μm, and all values ​​and subranges therebetween.

[0027] Downconverter materials or layers, such as phosphor-based materials or layers, absorb energy and convert incident wavelengths to higher wavelengths with lower energy. In one or more embodiments, the downconverter material includes a ceramic phosphor material or layer. Other downconverter materials may be phosphor particles and / or semiconductor nanoparticles (quantum dots), which may be used in combination with a binder to prepare the downconverter layer.

[0028] In one or more embodiments, the downconverter material is a Lumiramic® plate and / or phosphor powder embedded in a transparent matrix material. The Lumiramic plate is a polycrystalline ceramic plate of a phosphor material. The Lumiramic plate is a Ce(III)-doped garnet material ((M I 1-x-y M II x M III y )3(Al 1-z M IV z )5O 12 , where M I =(Y,Lu); M II =(Gd,La,Yb); M III =(Tb,Pr,Ce,Er,Nd,Eu) and M IV =(Gd,Sc), 0 < x < 1; 0 < y ≤ 1; and 0 < z < 1), or Ce(III) and / or Eu(II)-doped nitridosilicate (M2Si5N8), or oxynitridosilicate material (MSi2O2N2) (M = alkaline earth)) may be made.

[0029] In one or more embodiments, advantageously, the Lumiramic plate is combined with a blue-emitting LED die to generate white light in the range of a correlated color temperature (CCT) of 5000 - 7000K.

[0030] A light source including multiple light-emitting diodes (LEDs) includes a primary device material and a laser-modified device material to achieve a tailored color point distribution. The device material may be a downconverter material and / or a functional material. The tailored color point distribution includes improved color yield by modifying a portion of the LED's device material that distorts the reference color point distribution. Other tailored color point distributions provide new correlated color temperatures relative to the reference correlated color temperature through modifications to sections of the device material. The modifications to the device material may be performed by femtosecond laser irradiation. The modifications may include ablation for thickness reduction, roughening for surface topography changes, and / or three-dimensional shaping for emission tunability.

[0031] An "adjusted" color point distribution refers to the light characteristics achieved relative to a reference color point distribution upon modification of a reference light source. The reference light source includes multiple pixels and / or LEDs and does not include laser modification materials. In one or more embodiments, the adjusted color point distribution has a lower standard deviation compared to the reference color point distribution of the reference light source. In one or more embodiments, the center of gravity of the adjusted color point distribution (e.g., the "adjusted center of gravity") is different from the center of gravity of the reference color distribution of the reference light source (e.g., the "reference center of gravity"). For purposes of some examples, reference is made to the CIE 1976 color space, defined by (u',v') coordinates. Such analysis can equally be applied to the CIE 1931 color space, defined by (x,y) coordinates, or other defined color spaces. Various embodiments using five pixels and / or LEDs are illustrated herein. The devices and techniques herein apply to any number of LEDs or pixels in any quantity and in any array configuration.

[0032] In one or more embodiments, a blue-emitting LED die or pump is used in conjunction with a downconverter material, such as a Lumiramic plate, to generate white light. The devices herein are advantageously adapted for use in one or more specific automotive bins for front-lighting automobiles. In one or more embodiments, by way of example, any light source herein is effective to fill a first region in the CIE 1931 color space, the first region being a polygon with (x,y) vertices at (0.31, 0.348), (0.453, 0.44), (0.5, 0.44), (0.5, 0.38), (0.44, 0.38), and (0.31, 0.283).

[0033] A device containing multiple LEDs or pixels without laser modification is shown in FIG. 1, which is a schematic top view of a reference light source 10. Multiple pixels 11A, 11B, 11C, 11D, and 11E are shown. The use of five pixels is for illustrative purposes only. All of pixels 11A-11E contain the primary device material, e.g., downconverter material, in their prepared form. No laser modification was applied. FIG. 2 provides an exemplary graph of the color points of the light source's pixels, collectively showing the color point distribution 15 of the light source in FIG. 1 plotted for automotive color bins in the CIE 1976 color space. FIG. 2 is an exemplary reference color point distribution for a multi-pixel light source.

[0034] For illustrative purposes, the L1 color distribution along the v' axis of the reference illuminant is shown as a standard deviation of 2.7 points (schematically represented by the ellipse "2-A" in Figure 2). Such a spread is wider than the color sub-bins (H3b, H2c, H4a, etc.) used in automotive applications and may prevent optimal yield and performance in manufacturing. Examining Figure 2, pixels 11B and 11E are identified as outliers that skew the color point distribution. Pixel 11B is the source of the highest quantile of the reference color point distribution. Pixel 11E is the source of the lowest quantile of the reference color point distribution.

[0035] The techniques herein facilitate tuning the color point of phosphor-converted LEDs (pc-LEDs) after device materials, such as down materials, e.g., phosphor layers, or functional materials, have already been applied, which can be evaluated by a laser for processing.

[0036] Advantageously, more precise control of the LED color point and / or increased color uniformity is achieved, including from device to device or pixel to pixel within a single LED. Some of the benefits are (i) increased color yield, (ii) increased overall luminous flux distribution without color yield loss, (iii) achieving tighter specifications for LED color, and (iv) improved color to light source metrics. The functional materials can include one or more of a distributed Bragg reflector (DBR), a dichroic filter (DCF), a ceramic material, and a powdered phosphor layer.

[0037] Referring to FIG. 3, a schematic top view of a light source 50 is provided in accordance with one or more embodiments. A number of pixels 51A, 51B, 51C, 51D, and 51E are shown. The use of five pixels is again for illustrative purposes only. Given that pixels 11B and 11E in FIG. 1 are identified as the highest and / or lowest quantiles of the reference color point distribution, laser processing is applied to these pixels corresponding to pixels 51B and 51E in light source 50. Pixels 51A, 51C, and 51D are not laser modified. FIG. 4 provides an exemplary graph of color points for pixels of a light source, collectively illustrating the color point distribution 65 of the light source of FIG. 3 for automotive color bins in the CIE 1976 color space, in accordance with one or more embodiments. From FIG. 4, it can be seen that the resulting L1 color distribution along the v′ axis for a light source of the present invention is lower than that of FIG. 2 (as diagrammed by circle “4-A” in FIG. 4). Thus, in one or more embodiments, the adjusted color point distribution has a lower standard deviation compared to the reference color point distribution.

[0038] In some embodiments, with respect to the center of gravity of the reference color distribution, the center of gravity of the adjusted color point distribution of the laser modified device is different from the center of gravity of the reference color distribution.

[0039] The embodiments herein include two features: the phosphor-converted LED (pc-LED) on the reference color points is measured at the pixel level (FIG. 2); and the use of a laser to remove or change the roughness topography of the phosphor layer and / or functional layer to modify its light conversion properties (e.g., FIG. 4). Once the reference color points are measured, a reference color point distribution graph is generated.

[0040] In one or more embodiments, for color tuning, the incoming pc-LED device is measured for its baseline color point distribution (e.g., FIG. 2). The pc-LEDs or pixels that result in the highest and lowest quantiles of the color point distribution are identified (e.g., pixels 11B and 11E in FIG. 1). Surface treatment, e.g., laser treatment using a femtosecond laser, is then applied to irradiate the surface of the phosphor layer of the identified LED, resulting in laser-modified material (e.g., pixels 51B and 51E in FIG. 3). Irradiation can be performed in either an ablation mode (to reduce v') or a roughening mode (to increase v'). Femtosecond laser irradiation has sufficient spatial resolution (micrometer scale) and irradiance control to adjust the color point within the required accuracy. Therefore, laser irradiation is performed such that, after irradiation, the color points of the highest and lowest quantile pc-LEDs / pixels are returned closer to the median (FIG. 4). This results in a reduction of the overall color distribution.

[0041] The color point of a PC-LED changes as the amount of primary light conversion by the phosphor layer increases (v' increase) or decreases (v' decrease). The ablation mode of femtosecond laser irradiation allows for material removal while maintaining the same surface topology. Removal of the downconverter material, e.g., phosphor material, results in a decrease in primary light conversion (v' decrease). The roughening mode of femtosecond laser irradiation mostly changes the surface topology of the phosphor layer, resulting in increased scattering at the surface of the phosphor layer and therefore an increase in the additional passage of primary light within the phosphor layer. This is comparable to an increase in the "effective" thickness of the phosphor layer and therefore an increase in primary light conversion (v' increase). The overall color point can be increased or decreased (middle graph), depending on the mode used. Three-dimensional shaping can also be applied for tunability of the emission. A surface topology scan shows whether such modifications have been applied.

[0042] Advantageously, the use of laser processing to tailor the color point distribution of a light source can facilitate tailoring the favorable color point of the luminous flux without color yield loss. This results from achieving the desired center of gravity of the tailored color distribution. The technology herein also offers ease of color targeting in a manufacturing environment. That is, after a group of pc-LEDs is produced, further laser processing can allow for tailoring a specific phosphor layer manufacturing run. Utilization of pc-LEDs is improved by providing a method for matching more pc-LEDs to specific color subbins. The laser beam size is small enough that it can be applied to micro-LEDs to modify the color points of outlier pixels.

[0043] The principles of laser treatment can be applied to any type of pc device (pc-LED, group of pc-LEDs, assembly of pc-LEDs, pixelated LED, or microLED) to reduce either pixel-to-pixel color spread, pc-to-LED color spread, or device-to-device color spread. There are no limitations on the pattern of laser treatment. The type of pattern can be selected depending on the desired color point distribution and end application of the light source. Figures 5A-5B show schematic top views of an exemplary light source, including unmodified and laser-modified device materials. Figure 5A shows unmodified device material 131 and laser-modified device material 135a. Laser-modified device material 135a is a rectangular, continuous surface section. Figure 5B shows a series of laser-treated concentric rings 135b, 135c, and 135d, while the primary downconverter material 131 remains untreated.

[0044] For illustrative purposes, FIGS. 6-11 include five LEDs or pixels. The modified pixels shown correspond to those shown in FIG. 3. It should be understood that any number of pixels and array sizes may be used, and that the modifications to the LEDs or pixels are based on reference measurements to identify which LEDs or pixels are suitable for modification. The reference measurements may be used to create a reference measurement graph. Also, for illustrative purposes, the laser modification is shown as one section of ablation and one section of roughening per LED, but it should be understood that the number of sections modified and the type of modification (alation and / or roughening) are not limited and are determined based on the reference measurements and end use application.

[0045] FIG. 6 is a schematic cross-sectional view of a light source 100 including a group of light-emitting diodes (LEDs) including a primary downconverter material and a laser-modified downconverter material, according to one or more embodiments. The light source 100 includes a plurality of LEDs 102. Each LED 102 includes an LED pump 30 (a stack of semiconductor layers including an active region) and contacts 40 and 42, one of which is an anode and the other of which is a cathode. Above each LED pump is downconverter (e.g., phosphor) material, collectively sections 101A-101E. Downconverter material sections 101A, 101C, and 101D are primary downconverter material in that they are not laser-modified. Downconverter material sections 101B and 101E include laser-modified downconverter material. Any amount or portion of the downconverter material above the LED pump may be laser-modified, as long as some of the downconverter material remains on the LED pump in that section to provide light conversion. In this embodiment, the downconverter material in section 101B is ablated material and the downconverter material in section 101E is roughened material. In this embodiment, the sections of downconverter material 101A-101E are segmented layers on each LED.

[0046] FIG. 7 is a schematic cross-sectional view of a light source 105 including a group of LEDs including a primary functional material and a laser-modified functional material, according to one or more embodiments. The light source 105 includes a plurality of LEDs 107. Each LED 107 includes an LED pump (a stack of semiconductor layers including an active region) 30 and contacts 40 and 42, one of which is an anode and the other of which is a cathode. Above each LED pump is a downconverter (e.g., phosphor) material, collectively sections 106A-106E. Above the downconverter material is a functional material, collectively sections 108A-108E, on each of sections 106A-106E. Functional material portions 108A, 108C, and 108D are primary functional material in that they are not laser-modified. Functional material portions 108B and 108E are laser-modified functional material. In this embodiment, the functional material of section 108B is an ablation material that decreases in thickness across the width of the section. In this embodiment, the functional material of section 108E is an ablation material that decreases in width across the thickness of the section, thereby exposing the downconverter material of section 106E. In this embodiment, the sections of functional material 108A-108E are segmented layers on each LED.

[0047] FIG. 8 is a schematic cross-sectional view of a light source 110 including an array of LEDs on a device substrate including primary downconverter material and laser-modified downconverter material, according to one or more embodiments. The light source 110 includes a plurality of LEDs 112. Each LED 112 includes an LED pump 30 (a stack of semiconductor layers including an active region) and contacts 40 and 42, one of which is an anode and the other of which is a cathode. Above each LED pump is downconverter (e.g., phosphor) material, collectively sections 111A-111E. The LEDs are attached to the device substrate 15 by contacts 40 and 42. Downconverter material sections 111A, 111C, and 111D are primary downconverter material in that they are not laser-modified. Downconverter material sections 111B and 111E include laser-modified downconverter material. Any amount or portion of the downconverter material above the LED pump may be laser-modified, as long as some of the downconverter material remains on the LED pump in that section to provide light conversion. In this embodiment, the downconverter material in section 111B is ablated material and the downconverter material in section 111E is roughened material. In this embodiment, the sections of downconverter material 111A-111E are segmented layers on each LED.

[0048] FIG. 9 is a schematic cross-sectional view of a light source 115 comprising an array of LEDs on a device substrate including a primary functional material and a laser-modified functional material, according to one or more embodiments. The light source 115 includes a plurality of LEDs 117. Each LED 117 includes an LED pump (a stack of semiconductor layers including an active region) 30 and contacts 40 and 42, one of which is an anode and the other of which is a cathode. Above each LED pump is a downconverter (e.g., phosphor) material, collectively sections 116A-116E. Above the downconverter material is a functional material, collectively sections 118A-118E, on each of sections 116A-116E. Functional material portions 118A, 118C, and 118D are primary functional material in that they are not laser-modified. Functional material portions 118B and 118E are laser-modified functional material. In this embodiment, the functional material of section 118B is an ablation material that decreases in thickness across the width of the section. In this embodiment, the functional material of section 118E is an ablation material that decreases in width across the thickness of the section, thereby exposing the downconverter material of section 116E. In this embodiment, the sections of functional material 118A-118E are segmented layers on each LED.

[0049] FIG. 10 is a schematic cross-sectional view of a light source 120 comprising an array of uLEDs on a device substrate including a primary downconverter material and a laser-modified downconverter material, according to one or more embodiments. The light source 120 includes a plurality of uLEDs 122. Each uLED 122 comprises a stack of semiconductor layers including an active region 32 and contacts 40 and 42, one of which is an anode and the other of which is a cathode. On each uLED stack 32 is downconverter (e.g., phosphor) material, collectively sections 121A-121E. The uLEDs are attached to the device substrate 15 by contacts 40 and 42. Downconverter material sections 121A, 121C, and 121D are primary downconverter material in that they are not laser-modified. Downconverter material sections 121B and 121E include laser-modified downconverter material. Any amount or portion of the downconverter material on the uLED stack may be laser-modified, as long as some of the downconverter material remains on the uLED stack within that section to provide light conversion. In this embodiment, the downconverter material in section 121B is ablated material and the downconverter material in section 121E is roughened material. In this embodiment, the sections of downconverter material 121A-121E are part of a continuous layer over all of the uLEDs.

[0050] FIG. 11 is a schematic cross-sectional view of a light source 125 comprising an array of uLEDs on a device substrate including a primary functional material and a laser-modified functional material, according to one or more embodiments. The light source 125 includes a plurality of uLEDs 127. Each uLED 127 comprises a stack of semiconductor layers including an active region 32 and contacts 40 and 42, one of which is an anode and the other of which is a cathode. Above each uLED stack 32 is a downconverter (e.g., phosphor) material, collectively sections 126A-126E. Above the downconverter material is a functional material, collectively sections 128A-128E, on each of sections 126A-126E. Functional material portions 128A, 128C, and 128D are primary functional material in that they are not laser-modified. Functional material portions 128B and 128E are laser-modified functional material. In this embodiment, the functional material of section 128B is an ablative material that decreases in thickness across the width of the section. In this embodiment, the functional material of section 128E is an ablated material that decreases in width across the thickness of the section, thereby exposing the downconverter material of section 126E. In this embodiment, the sections of functional material 128A-128E are part of a continuous layer on the continuous downconverter material on each LED.

[0051] Furthermore, with respect to laser processing and near-field LED emission, patterning can be configured to generate a gradient or specific pattern of emission profile on top of the downconverter material. One example of a downconverter material is a polycrystalline ceramic plate of phosphor material, such as a Lumiramic plate. The following metrics can potentially be patterned: color point (color on the light source), angular color, luminous flux, and emission profile. The following embodiments can be used to achieve the patterning objective: patterned ablation of the surface of the downconverter material; patterned roughening of the surface of the downconverter material; patterning of a functional material or layer located on top of the downconverter material; and attachment of an offset platelet to the die. With respect to patterning, it is generally considered that the patterning does not extend through the entire thickness of the downconverter layer. In one or more embodiments, patterning of the functional layer allows for surface patterning and / or patterning through the entire thickness of the functional material.

[0052] 11A-16B, variations of the downconverter material and / or functional material on the LED are shown. The LED in all figures comprises an LED pump 203 (which is a stack of semiconductor layers including the active region) and contacts 204 and 206, one of which is the anode and the other of which is the cathode.

[0053] FIG. 12 provides an example graph of color point distributions of two illuminants for automotive color bins in CIE 1976 color space. The reference illuminant produces a color point distribution 210 with a centroid 210c within color bin "H3b." The target or desired illuminant produces a color point distribution 220 with a centroid 220c within color bin "H2c." For illustrative purposes, the first reference illuminant should be modified to reside within, or at least closer to, the "H2c" color bin. The reference illuminant is then laser processed in accordance with the techniques herein.

[0054] FIG. 13 provides an example graph of the color point distributions of two light sources for automotive color bins in the CIE 1976 color space. The reference light source of FIG. 11 was laser modified to result in a new color distribution 215 whose centroid 215c is closer to the "H2c" color bin and, similarly, closer to the centroid 220c of the target or desired light source. The color point distributions 210 and 220 of FIG. 12 are substantially overlapping in FIG. 13. Patterning can advantageously achieve color uniformity across the light source, tailored color response, and / or improved color target / yield. Ablative treatments can be one way to achieve this. Patterning can also advantageously target the emission profile. For example, the angle of escape light can be altered in certain areas, so the optical system may collect more light from those specific areas. Roughening can be one way to achieve this.

[0055] The functional material may include one or more of a distributed Bragg reflector (DBR), a dichroic filter (DCF), a ceramic material, and a powdered phosphor layer.

[0056] Generally, modifying the DBR affects the light flux. The DBR can form a partially reflective mirror. Laser patterning is useful for directing less light to a specific spot on the road for headlight applications.

[0057] DCFs can be used as partial mirrors similar to DBRs, or to correct color as a function of angle over specific areas.

[0058] Ceramic materials, such as multilayer ceramics, can be tape-cast, which is useful for having different compositions along the z-axis. Ablation patterning can also enable color tuning along u'.

[0059] The powder phosphor layer can be laminated, for example, as a film, onto the downconverter material (e.g., a ceramic phosphor layer). In one or more embodiments, the red film can be layered, for example, an ALD-bonded red layer. Patterning can be used for color tuning or to project different colors onto specific areas.

[0060] FIG. 14A is a cross-sectional view of an LED light source, which may include one or more pixels or LEDs, according to an embodiment, and in which metal contacts may be added for further use. In FIG. 14A, light source 250 includes downconverter material 201 on one or more pixels and / or LEDs 290. A laser-modified portion 207B of the downconverter material is also included. In this embodiment, laser-modified portion 207B is a roughened material. The roughened material changes the surface topology and / or three-dimensional shape of the phosphor layer, which results in increased scattering at the surface of the phosphor layer and therefore increased additional transmission of primary light within the phosphor layer. This is comparable to an increase in the "effective" thickness of the phosphor layer and therefore an increase in primary light conversion (increased v'). In one or more embodiments, roughening one or more pixels or LEDs alone is effective for color tuning.

[0061] Figure 14B is a cross-sectional view of an LED light source, which may include one or more pixels or LEDs, according to an embodiment, and in which metal contacts would be added for further use. In Figure 14B, light source 255 includes downconverter material 201 on one or more pixels and / or LEDs 290. Laser-modified portions 207A and 207B of the downconverter material are also included. In this embodiment, laser-modified area 207A is further ablated material relative to laser-modified area 207B, which is roughened material.

[0062] Offsetting the downconverter material, e.g., Lumiramic, can also create a luminous flux / brightness gradient across the light-emitting area. This can be combined with the patterning options described herein. Figures 15A and 15B are schematic cross-sectional views of light sources, each including one or more light-emitting diodes (LEDs) according to an embodiment, with metal contacts added for further use. In Figure 15A, light source 260 includes one or more pixels and / or LEDs 290 onto which downconverter material 201 is offset and attached by a layer of adhesive 211. Laser-modified portions 207A and 207B of downconverter material are also included. In this embodiment, the downconverter material in section 207A is ablated material, while the downconverter material in section 207B is roughened material. In Figure 15B, light source 265 includes downconverter material 201 offset onto one or more pixels and / or LEDs 290 and attached by a layer of adhesive 211, which further includes adhesive wings 212. Similar to FIG. 15A, the laser treated downconverter material in section 207A is ablated material, and the laser treated downconverter material in section 207B is roughened material.

[0063] 16A and 16B are schematic cross-sectional views of light sources, each including one or more light-emitting diodes (LEDs) according to an embodiment, with metal contacts added for further use. In FIG. 16A, light source 270 includes one or more pixels and / or LEDs 290 onto which downconverter material 201 is offset and affixed by a layer of adhesive 211. Laser-modified portions 207A and 207B of the downconverter material are also included. Functional material 208 is on the downconverter material and the laser-modified portions. In this embodiment, the downconverter material in section 207A is ablated material, and the downconverter material in section 207B is roughened material. In FIG. 16B, light source 275 includes downconverter material 201 offset onto one or more pixels and / or LEDs 290 and affixed by adhesive layer 211, which further includes adhesive wings 212. 16A, the laser treated downconverter material in section 207A is ablated material and the laser treated downconverter material in section 207B is roughened material. Functional material 208 is on the downconverter material and the laser modified portion.

[0064] Figure 17 is a cross-sectional view of an LED light source, which may include one or more pixels or LEDs, according to an embodiment, and in which metal contacts would be added for further use. In Figure 17, light source 410 includes functional material 408 on downconverter material 401 on one or more pixels and / or LEDs 402. Laser-modified portions 409A and 409B of the functional material are also included. In this embodiment, the functional material in sections 409A and 409B is ablated material. Laser-modified functional material 409A is modified through the thickness of the material. Laser-modified functional material 409B is modified across the width of the material.

[0065] 18A and 18B are schematic cross-sectional views of an LED light source, which may include one or more pixels or LEDs, according to an embodiment, to which metal contacts are added for further use. In FIG. 18A, light source 420 includes functional material 408 on downconverter material 401, both of which are offset above one or more pixels and / or LEDs 402, with downconverter material 401 affixed to one or more pixels and / or LEDs 402 by adhesive layer 411. Laser-modified portions 409A and 409B of functional material are also included. In this embodiment, the functional material of sections 409A and 409B is ablated material. Laser-modified functional material 409A is modified throughout the thickness of the material. Laser-modified functional material 409B is modified across the width of the material. In Figure 18B, light source 430 includes functional material 408 and downconverter material 401, both offset over one or more pixels and / or LEDs 402, with downconverter material 401 affixed by adhesive layer 411, which further includes adhesive wings 412. As in Figure 18A, the laser-treated functional material in sections 409A and 409B is ablated material. Similarly, laser-modified functional material 409A is modified through the thickness of the material. Laser-modified functional material 409B is modified across the width of the material.

[0066] FIG. 19 provides a process flow diagram 300 for manufacturing a light source according to one or more embodiments. In operation 310, a reference color point distribution of a reference light source is measured. In operation 320, the reference color point distribution is prepared. The reference color point distribution is analyzed to determine what, if any, adjustments to the reference light source are necessary. For example, deviations from the adjusted color point distribution warrant adjustments to the reference light source. In operation 330, one or more sections of device material are identified for laser processing. The device material can be evaluated by a laser for processing. The device material can include, but is not limited to, down materials, such as phosphor layers, or functional materials.

[0067] In operation 340, laser treatment is applied to a portion of the surface of the device material. As described herein, suitable laser treatments can include the use of a femtosecond laser. In one or more embodiments, irradiation is performed in either an ablation mode (to reduce v') or a roughening mode (to increase v'). Femtosecond laser irradiation has sufficient spatial resolution (micrometer scale) and irradiance control to adjust the color point within the required precision.

[0068] In operation 350, any further post-processing is performed. In one or more embodiments, further processing includes forming a passivation layer around part or all of the LED or uLED, or the entire device. In one or more embodiments, the processed structure retains the substrate, is singulated, and further processed. In one or more embodiments, the processed structure is flipped over and attached to a support, such as a tape support, and the substrate is removed. Removal of the substrate follows methods known in the art, including substrate laser lift-off. Removal of the substrate creates singulated LEDs or uLEDs.

[0069] In some embodiments, the LED devices herein are further processed to include optical elements such as lenses, metalenses, and / or pre-collimators. The optical elements can additionally or alternatively include apertures, filters, Fresnel lenses, convex lenses, concave lenses, or any other suitable optical elements that affect the projected light from the light-emitting array. Furthermore, one or more of the optical elements can have one or more coatings, including UV-blocking or anti-reflective coatings. In some embodiments, the optical elements can be used to correct or minimize two-dimensional or three-dimensional optical errors, including pincushion distortion, barrel distortion, axial chromatic aberration, spherical aberration, chromatic aberration, field curvature, astigmatism, or any other type of optical error. In some embodiments, the optical elements can be used to magnify and / or correct the image. Advantageously, in some embodiments, magnifying the display image allows the light-emitting array to be physically smaller, lighter, and require less power than larger displays. Furthermore, magnification can increase the field of view of the displayed content, allowing the display presentation to be equivalent to the user's normal field of view.

[0070] application 20 schematically illustrates an example headlight lighting system 700 utilizing the LEDs disclosed herein. The headlight lighting system 700 includes an LED lighting array and lens system 702 electrically connected to an LED driver 704. The headlight lighting system 700 also includes a controller 706, such as a microprocessor. The controller 706 is coupled to the LED driver 704. The controller 706 is also coupled to one or more auxiliary components 708 and sensors 710 associated with the headlight, and may operate according to instructions and profiles stored in a memory 712.

[0071] Sensors 710 may include, for example, position sensors (e.g., gyroscopes and / or accelerometers) and / or other sensors that may be used to determine the position, velocity, and orientation of system 700. Signals from sensors 710 may be provided to controller 706 to be used to determine the appropriate course of action for controller 706 (e.g., which LEDs are currently illuminating the target and which LEDs will be illuminating the target after a predetermined time).

[0072] During operation, illumination from some or all of the pixels of the LED array in 702 can be adjusted to be deactivated, operated at full intensity, or operated at intermediate intensities. As mentioned above, beam focusing or steering of the light emitted by the LED array in 702 can be performed electronically by activating one or more subsets of the pixels, allowing dynamic adjustment of the beam shape without moving optics within the illumination device or changing the focus of a lens.

[0073] LED lighting arrays and lens systems as described herein can support a variety of other beam steering or other applications that benefit from fine intensity, spatial, and temporal control of light distribution. These applications may include, but are not limited to, precise spatial patterning of emitted light from pixel blocks or individual pixels. Depending on the application, the emitted light may be spectrally distinct, adaptive over time, and / or environmentally responsive. Light-emitting pixel arrays may provide preprogrammed light distributions with varying intensity, spatial, or temporal patterns. Associated optical elements may be distinct at the pixel, pixel block, or device level. An exemplary light-emitting pixel array may include a device with a commonly controlled central block of high-brightness pixels with associated common optical elements, while edge pixels may have individual optical elements. In addition to flashlights, common applications supported by light-emitting pixel arrays include video lighting, camera flashes, architectural and area lighting, and street lighting.

[0074] In some embodiments, each LED device in a light source array can be controlled separately, while in other embodiments, groups of LEDs can be controlled as a block. In still other embodiments, both single LEDs and groups of LEDs can be controlled. To reduce overall data management requirements, control can be limited to an on / off function or switching between relatively few light intensity levels. In other embodiments, continuous changes in illumination intensity are supported. Both individual and group-level control of light intensity are contemplated. In one embodiment, overlapping or dynamically selected zones of control are also possible; for example, overlapping groups of light emitters in an array can be separately controlled despite having common LEDs depending on lighting requirements. In one embodiment, intensity can be separately controlled and adjusted by using pulse-width modulation to set the appropriate ramp time and pulse width for each LED. This allows for staging of LED activation, reducing power fluctuations and providing superior luminosity control.

[0075] Programmable light-emitting arrays as disclosed herein can also support a wide range of applications that benefit from fine-grained intensity, spatial, and temporal control of light distribution. This can include, but is not limited to, precise spatial patterning of emitted light from blocks or individual LEDs. Depending on the application, the emitted light can be spectrally distinct, adaptive over time, and / or environmentally responsive. In some embodiments, the light-emitting array may provide pre-programmed light distributions with varying intensity, spatial, or temporal patterns. The emitted light can be based at least in part on received sensor data and can be used for optical wireless communication. Associated optics can vary at the single or multiple LED level. An exemplary light-emitting array can include a device with a commonly controlled central block of high-brightness LEDs with associated common optics, while edge-located LEDs can have individual optics. Typical applications supported by light-emitting LED arrays include camera or video lighting, architectural and area lighting, and street lighting.

[0076] Programmable light-emitting arrays can be used to selectively and adaptively illuminate buildings or areas to improve visual displays or reduce lighting costs. Additionally, light-emitting arrays can be used to project media facades for decorative motion or video effects. In conjunction with tracking sensors and / or cameras, selective illumination of areas surrounding pedestrians may be possible. Spectrally distinct LEDs can be used to adjust the color temperature of the lighting and support wavelength-specific horticultural lighting.

[0077] Street lighting is an important application that can greatly benefit from the use of programmable light-emitting arrays. A single type of light-emitting array can be used to mimic various street light types, for example, switching between a Type I linear street light and a Type IV semicircular street light by appropriately activating or deactivating selected LEDs. Also, street lighting costs can be reduced by adjusting the intensity and distribution of the light beam depending on environmental conditions and time of use. For example, light intensity and distribution area can be reduced when pedestrians are absent. If the LEDs are spectrally distinct, the color temperature of the light can be adjusted according to the respective daylight, twilight, or nighttime conditions.

[0078] Programmable light-emitting LEDs are also well suited to support applications requiring direct or projected displays. For example, automobile headlights requiring calibration, or warning, emergency, or informational signs, can all be displayed or projected using a light-emitting array. This allows, for example, the directionality of the light output from the automobile's headlights to be varied. If the light-emitting array is composed of multiple LEDs or includes an appropriate dynamic light mask, text or numerical information can be presented in a user-guided arrangement. Directional arrows or similar indicators can also be provided.

[0079] Embodiment Various embodiments are listed below, and it is understood that the embodiments listed below can be combined with all aspects and other embodiments in accordance with the scope of the present invention.

[0080] Embodiment (a): A light source comprising a plurality of light emitting diodes (LEDs), a plurality of sections of primary downconverter material corresponding to a first plurality of said LEDs, one or more sections of laser-modified downconverter material corresponding to a second plurality of said LEDs, a light-blocking layer positioned between all of said LEDs, and a tuned color point distribution of said light source as a whole.

[0081] Embodiment (b): The light source of embodiment (a), wherein the multiple sections of primary downconverter material and the one or more sections of laser-modified downconverter material are segmented layers on each LED.

[0082] Embodiment (c): The light source of embodiment (a) or (b), wherein one or more of the segmented layers of the plurality of sections of the primary downconverter material and the one or more sections of the laser-modified downconverter material are offset from a center on the respective LED.

[0083] Embodiment (d): The light source of any of embodiments (a)-(c), wherein the continuous downconverter layer over all of the LEDs comprises multiple sections of primary downconverter material and one or more sections of laser-modified downconverter material.

[0084] Embodiment (e): The light source of any of embodiments (a)-(d), wherein one or more sections of the laser-modified downconverter material are modified during measurement of a reference color point distribution of a reference light source comprising a plurality of light emitting diodes in the absence of any sections of the laser-modified downconverter material to achieve a tailored color point distribution.

[0085] Embodiment (f): The light source of any of embodiments (a)-(e), wherein the adjusted color point distribution has a lower standard deviation compared to a reference color point distribution of a reference light source comprising a plurality of light emitting diodes without any section of the laser-modified downconverter material present.

[0086] Embodiment (g): The light source of embodiment (a), wherein the center of gravity of the adjusted color point distribution is different from the center of gravity of a reference light source comprising a plurality of light emitting diodes without any section of the laser-modified downconverter material present.

[0087] Embodiment (h): The light source of any of embodiments (a)-(g), wherein one or more sections of the laser-modified downconverter material comprise a reduced thickness and / or a changed surface topography and / or three-dimensional shaping for emission tunability relative to the primary downconverter material.

[0088] 10. A light source comprising: a monolithic body comprising a plurality of micro light emitting diodes (uLEDs), each of the uLEDs having at least one characteristic dimension greater than or equal to 1 micrometer and less than or equal to 300 micrometers, the characteristic dimension selected from the group consisting of height, width, depth, thickness, and combinations thereof; a continuous downconverter layer over all of the uLEDs, the continuous downconverter layer comprising a plurality of sections of primary downconverter material corresponding to a first plurality of the uLEDs and one or more sections of laser-modified downconverter material corresponding to a second plurality of the uLEDs, the one or more sections of laser-modified downconverter material comprising, relative to the primary downconverter material, a reduced thickness and / or a changed surface topography and / or three-dimensional shaping for emission tuning; a light-blocking layer positioned between all of the uLEDs; and a tuned color point distribution of the light source as a whole.

[0089] Embodiment (j): The light source of embodiment (i), wherein the one or more sections of the laser-modified downconverter material are modified during measurement of a reference color point distribution of a reference light source comprising a plurality of micro light emitting diodes in the absence of any sections of the laser-modified downconverter material to achieve the adjusted color point distribution.

[0090] Embodiment (k): The light source of embodiment (i) or (j), wherein the adjusted color point distribution has a lower standard deviation compared to a reference color point distribution of a reference light source comprising a plurality of micro light emitting diodes without any sections of the laser-modified downconverter material present.

[0091] Embodiment (l): The light source of any of embodiments (i) to (k), wherein the adjusted color point distribution has a center of gravity of the adjusted color distribution that is different from the center of gravity of a reference color distribution of a reference light source including a plurality of micro light emitting diodes in the absence of any section of the laser-modified downconverter material.

[0092] Embodiment (m): The light source of any of embodiments (i) through (l), further comprising a functional material on the continuous downconverter layer.

[0093] Embodiment (n): A method for manufacturing a light source comprising a plurality of light emitters, comprising the steps of measuring a reference color point distribution of a reference light source comprising a plurality of light emitting diodes (LEDs) and a primary downconverter material in the absence of the laser-modified downconverter material; creating a reference color point distribution graph; identifying one or more sections of the primary downconverter material in which the corresponding LEDs contribute to deviations from the adjusted color point distribution; and applying laser treatment to the one or more sections of the primary downconverter material in which the corresponding LEDs contribute to deviations from the adjusted color point distribution to prepare the one or more sections of the laser-modified downconverter material, thereby preparing a light source having the adjusted color point distribution.

[0094] Embodiment (o): The method of embodiment (n) comprising the steps of identifying one or more highest and / or lowest quantiles of the reference color point distribution, identifying one or more of the LEDs as generators of the one or more highest and / or lowest quantiles of the reference color point distribution, and applying a laser treatment to sections of the primary downconverter material corresponding to one or more of the LEDs that are generators of the one or more highest and / or lowest quantiles of the reference color point distribution.

[0095] Embodiment (p): The method of embodiment (n) or (o), wherein the adjusted color point distribution has a lower standard deviation compared to the reference color point distribution.

[0096] Embodiment (q): The method of any of embodiments (n)-(p), wherein the center of gravity of the adjusted color point distribution is different from the center of gravity of the reference color point distribution.

[0097] Embodiment (r): The method of any of embodiments (n)-(q), wherein the laser treatment comprises femtosecond laser irradiation.

[0098] Embodiment(s): The method of any of embodiments (n) through (r), wherein each of the LEDs has at least one characteristic dimension of greater than or equal to 1 micrometer and less than or equal to 300 micrometers, the characteristic dimension being selected from the group consisting of height, width, depth, thickness, and combinations thereof.

[0099] Embodiment (t): The method of any one of embodiments (n)-(s), wherein the laser processing comprises ablation for thickness reduction, and / or roughening for surface topography alteration, and / or three-dimensional shaping for emission tunability.

[0100] Embodiment (u): Any of the preceding embodiments (a)-(t) wherein the LED is mounted on a submount.

[0101] Embodiment (v): Any of the preceding embodiments (a)-(u), wherein the LED is integrated into a monolithic body.

[0102] Embodiment (w): Any of the preceding embodiments (a)-(v), wherein the primary downconverter material comprises a polycrystalline ceramic plate of phosphor material.

[0103] Embodiment (x): The phosphor material is a Ce(III)-doped garnet material ((M I 1-x-y M II x M III y )3(Al 1-z M IV z )5O 12 , M I =(Y,Lu);M II =(Gd,La,Yb);MIII =(Tb, Pr, Ce, Er, Nd, Eu) and M IV =(Gd, Sc), 0 < x < 1; 0 < y ≤ 1; and 0 < z < 1), or Ce(III) and / or Eu(II)-doped nitridosilicate (M2Si5N8), or oxynitridosilicate material (MSi2O2N2) (M = alkaline earth), a light source or method according to any of embodiments (a) to (w).

[0104] Embodiment (y): A light source or method according to any of embodiments (a) to (x), wherein the light source is effective to fill a first region in the CIE1931 color space, the first region being a polygon having (x, y) vertices of (0.31, 0.348), (0.453, 0.44), (0.5, 0.44), (0.5, 0.38), (0.44, 0.38), and (0.31, 0.283).

[0105] Embodiment (z): An LED or uLED comprising a stack of semiconductor layers including an active region, a light source or method according to any of embodiments (a) to (y).

[0106] Throughout this specification, references to "one embodiment", "an embodiment", "one or more embodiments", or "embodiments" mean that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "in one or more embodiments", "in a particular embodiment", "in one embodiment", or "in an embodiment" throughout this specification are not necessarily referring to the same embodiment of the present disclosure. Further, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0107] Many modifications and other embodiments of the invention will come to mind to one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. It is understood, therefore, that the invention is not limited to the particular embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims. It is also understood that other embodiments of the invention may be practiced in the absence of elements / steps not specifically disclosed herein.

Claims

1. A light source comprising: A plurality of light emitting diodes (LEDs); a plurality of sections of a primary downconverter material corresponding to a first plurality of said LEDs; one or more sections of laser-modified downconverter material corresponding to a second plurality of said LEDs; a light blocking layer positioned between all of the LEDs; and a tuned color point distribution of the light source as a whole.

2. The light source of claim 1 , wherein the multiple sections of the primary downconverter material and the one or more sections of the laser modified downconverter material are segmented layers on each LED.

3. 3. The light source of claim 2, wherein one or more of the segmented layers of the multiple sections of the primary downconverter material and the one or more sections of the laser modified downconverter material are offset from center on the respective LED.

4. 10. The light source of claim 1, wherein a continuous downconverter layer over all of the LEDs includes the multiple sections of the primary downconverter material and the one or more sections of the laser modified downconverter material.

5. 2. The light source of claim 1, wherein the one or more sections of the laser-modified downconverter material are modified during measurement of a reference color point distribution of a reference light source including a plurality of light emitting diodes in the absence of any sections of the laser-modified downconverter material to achieve the adjusted color point distribution.

6. 2. The light source of claim 1, wherein the adjusted color point distribution has a lower standard deviation compared to a reference color point distribution of a reference light source including a plurality of light emitting diodes in the absence of any sections of the laser modified downconverter material.

7. 10. The light source of claim 1, wherein the center of gravity of the adjusted color point distribution is different from the center of gravity of a reference light source comprising a plurality of light emitting diodes without any sections of the laser modified downconverter material being present.

8. The light source of claim 1 , wherein the one or more sections of the laser-modified downconverter material include a reduced thickness and / or a changed surface topography and / or a three-dimensional shaping for emission tunability compared to the primary downconverter material.

9. A light source comprising: A monolithic body including a plurality of micro light emitting diodes (uLEDs), each of the uLEDs having at least one characteristic dimension greater than or equal to 1 micrometer and less than or equal to 300 micrometers, the characteristic dimension being selected from the group consisting of height, width, depth, thickness, and combinations thereof; a continuous downconverter layer over all of the uLEDs, the continuous downconverter layer including a plurality of sections of a primary downconverter material corresponding to a first plurality of the uLEDs and one or more sections of a laser-modified downconverter material corresponding to a second plurality of the uLEDs, the one or more sections of the laser-modified downconverter material including a reduced thickness and / or a changed surface topography and / or a three-dimensional shaping for emission tunability compared to the primary downconverter material; a light blocking layer positioned between all of the uLEDs; and a tuned color point distribution of the light source as a whole.

10. 10. The light source of claim 9, wherein the one or more sections of the laser-modified downconverter material are modified during measurement of a reference color point distribution of a reference light source comprising a plurality of micro light emitting diodes in the absence of any sections of the laser-modified downconverter material to achieve the adjusted color point distribution.

11. 10. The light source of claim 9, wherein the adjusted color point distribution has a lower standard deviation compared to a reference color point distribution of a reference light source comprising a plurality of micro light emitting diodes in the absence of any sections of the laser modified downconverter material.

12. 10. The light source of claim 9, wherein the adjusted color point distribution has a center of gravity of the adjusted color distribution that is different from a center of gravity of a reference color distribution of a reference light source including a plurality of micro light emitting diodes in the absence of any section of the laser modified downconverter material.

13. The light source of claim 9 further comprising a functional material on the continuous downconverter layer.

14. 1. A method for manufacturing a light source including a plurality of light emitters, comprising the steps of: measuring a reference color point distribution of a reference light source including a plurality of light emitting diodes (LEDs) and a primary downconverter material without the presence of the laser-modified downconverter material; preparing a reference color point distribution graph; identifying one or more sections of the primary downconverter material that contribute to a deviation of a corresponding LED from a tailored color point distribution; and applying a laser treatment to the one or more sections of the primary downconverter material whose corresponding LEDs contribute to a deviation from the adjusted color point distribution to prepare one or more sections of laser-modified downconverter material, thereby preparing a light source having the adjusted color point distribution.

15. identifying one or more highest and / or lowest quantiles of the reference color point distribution; Identifying one or more of the LEDs as generators of the one or more highest and / or lowest quantiles of the reference color point distribution. and applying the laser treatment to the sections of primary downconverter material that correspond to the one or more of the LEDs that are generators of the one or more highest and / or lowest quantiles of the reference color point distribution.

16. The method of claim 14 , wherein the adjusted color point distribution has a lower standard deviation compared to the reference color point distribution.

17. The method of claim 14 , wherein the center of gravity of the adjusted color point distribution is different from the center of gravity of the reference color point distribution.

18. The method of claim 14 , wherein the laser treatment comprises femtosecond laser irradiation.

19. 15. The method of claim 14, wherein each of the LEDs has at least one characteristic dimension greater than or equal to 1 micrometer and less than or equal to 300 micrometers, the characteristic dimension being selected from the group consisting of height, width, depth, thickness, and combinations thereof.

20. The method of claim 14 , wherein the laser processing comprises ablation for thickness reduction and / or roughening for surface topography modification and / or three-dimensional shaping for emission tunability.

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