Increase Light Extraction from Micro-LEDs

Display panels with high-efficiency micro-LED structures for high resolution, high brightness displays. The micro-LED design has a conductive side arm that contacts the bottom layer of the LED stack to improve the p-type ohmic contact and avoid shadowing of emitted light. The LED also has a composite reflective layer under the bottom contact to maximize light extraction. The micro-LED structure includes a bottom conductive layer, a light emitting layer, top contact, a dielectric layer, and the conductive side arm connecting the bottom layer. The composite reflective layer includes insulating and metallic layers.

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An optical device with improved light extraction efficiency and manufacturing method. The method involves forming spacers on the sidewalls of a sacrificial mesa, depositing a reflective metallic layer on the spacers, removing the mesa to create a pocket between the spacers, and installing a die with vertical sidewalls into the pocket. The spacers and reflective layer help direct and reflect light generated in the die toward the top surface for extraction. This improves extraction compared to conventional LEDs, where light can be trapped and absorbed in the sidewalls. The spacers and reflective layer provide an optical cavity around the die to enhance light's internal reflection and extraction.

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Micro-LED arrays are formed using vertical sidewall spacers to enhance light extraction. The devices have a light-emitting structure with vertical sidewalls, an optically transparent spacer layer with an internal face facing the sidewalls to enhance light extraction and a reflective conducting mirror layer on the external face of the spacer.

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Micro-LED display panel with improved efficiency and fabrication method. The micro-LED structure has a unique design to enhance light extraction efficiency. It includes a conductive side arm that connects the bottom layer of the LED to the bottom contact layer. This creates a vertical current path that avoids current crowding and improves uniform current spreading. The LED also has a composite reflective layer underneath the bottom contact to increase reflectivity. This helps trap and redirect oblique angle light for extraction. The micro-LED structure uses a transparent isolation layer to cover the sidewalls and protrude the top of the LED layers, allowing a top contact to be added over the transparent layer.

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A method to optimize light extraction efficiency of small micro-LEDs and improve their brightness. The method involves forming spacers on the sidewalls of the LED mesa using an insulating material. A transparent conducting oxide layer is then deposited on the top surface of the mesa, followed by a reflective conducting layer. The spacers and transparent oxide layer act as an optical cavity to enhance light extraction. The insulating spacers prevent electrical leakage between the transparent and reflective layers. This prevents damage to the active region while maximizing light extraction.

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Micro-LED design with high extraction efficiency for displays. The LED has a conductive bottom layer, a light-emitting layer, and a top conductive layer. It includes a protruding section on the bottom layer that extends beyond the other layers. A transparent isolation layer covers this protrusion. A side arm connects the bottom layer to the bottom conductive layer. The bottom conductive layer also has a composite reflective layer underneath.

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Micro-LED display panels with high-efficiency pixels for high resolution, high brightness displays like AR and VR devices. The micro-LED pixels have a unique structure with improved light extraction efficiency, high reflectivity, and good ohmic contacts. The key features are a conductive side arm that contacts the bottom layer of the LED stack, a composite metal-dielectric reflective layer beneath the LED stack, and a protruding top layer covered by a transparent isolation layer. This design reduces light trapping, improves reflectivity, and allows better electrical contacts.

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A micro-LED structure for AR/VR displays with improved light patterns uses optical structures like lenses and reflective cups over each micro-LED chip. The micro-LED structure includes multiple micro-LED chips arranged in a line, each with a reflective coating around the sidewalls. Optical structures, such as asymmetric lenses and reflective cups, are placed over each micro-LED chip to shape and direct the light output.

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An LED assembly to improve micro-LEDs' light efficiency, brightness, and integration. The assembly involves vertically aligning micro-LEDs into the substrate through holes rather than laying flat. This optimized alignment significantly improves light efficiency, brightness, and integration of the micro-LEDs compared to horizontal alignment.

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Display panels with integrated micro-lens arrays and pixel structures for high resolution, high brightness displays with reduced power consumption. The display panels include micro-lenses aligned to pixel light sources to reduce light divergence and improve extraction efficiency. The pixel structures have multi-color LEDs stacked vertically with reflective layers to prevent crosstalk. The stacked LEDs are bonded with dielectric layers and connected to a common electrode. The vertical arrangement allows high resolution within each pixel while the micro-lenses increase overall brightness. The reduced divergence and improved extraction efficiency provide high brightness for better viewing angles and reduced power waste.

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Micro-LED display technology with high light extraction efficiency for improved efficiency and reduced power consumption compared to OLED displays. High-efficiency micro-LED displays are particularly useful in mobile devices with critical battery life. The micro-LEDs are made from nanowires with textured semiconductor materials to scatter and extract more light.

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Display devices using micro-LEDs with improved light extraction efficiency and a manufacturing method for the same. The micro-LEDs have protrusions on their surface, roughness, and nanoparticles that scatter light, allowing more efficient extraction. The protrusions are formed by coating the LED with an organic layer containing nanoparticles and etching the layer to leave behind the protrusions and roughness. This simple and inexpensive organic layer process enhances light extraction compared to conventional dry or wet etching methods.

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Micro LED structure that improves efficiency and brightness of micro-LED devices. The micro-LED structure has a light emitting layer that extends horizontally beyond the top and bottom electrodes, unlike conventional designs where the light emitting layer is sandwiched strictly between the electrodes. This allows more light extraction and reduces absorption losses. The micro-LED structure can also include shared spacers and isolation structures between multiple micro-LEDs on a chip to further enhance efficiency.

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Micro-LED structure with enhanced brightness. The micro-LED structure includes a first conductive layer, a second conductive layer, and a light emitting layer between them. The light emitting layer extends horizontally away from the edges of the conductive layers without contacting them. This allows the light emitting layer to extend further and emit more light compared to conventional micro-LED designs where the light emitting layer is sandwiched between the conductive layers.

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MicroLED structure with improved light extraction efficiency for use in displays, using shared light emitting layer. The structure includes microLEDs with a top and bottom contact layer and a continuous light emitting layer in between. The LEDs share the same emission layer. This allows the layer to be optimized for light extraction efficiency. The shared layer extends horizontally beyond the contact layers to avoid contact and improve extraction.

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Micro-sized face-up LED device for visible light communication applications. The device has a high efficiency micro-hole array structure that allows more light extraction. The LED is prepared from a GaN-based epitaxial layer with a central current spreading layer and etched N-GaN layer surrounded by passivation.

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Micro light emitting diode (LED) that boosts light extraction and efficiency, and a manufacturing method of the micro LED. The micro LED has a vertical side surface for better light extraction and a tilted side surface to increase LED density. By surrounding the sides with insulating and reflective layers, light emitted from the tilted side is reflected and extracted from the vertical side. This improves light extraction efficiency. The manufacturing method involves etching the vertical side after the tilted side is formed.

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Micro-LED display technology that enables mass production of high efficiency, high brightness micro-LED displays. The display uses nanorod-type micro-LEDs with a functional material layer that increases light extraction. The functional layer has gradually decreasing refractive index away from the LED surface to reduce total internal reflection. The display further uses pixel plates containing multiple subpixels with differently composed nanorod LEDs to emit different colors.

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Micro-LED arrays and micro-lens arrays to improve the efficiency of micro-LED-based displays. The micro-LEDs have optimized mesa shape and back reflectors to increase extraction efficiency. The micro-LEDs are combined with micro-lenses that extract and direct the light for improved coupling into display systems and user eyes.

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Increasing light extraction efficiency from microLEDs by modifying the GaN layer using ion implantation. The GaN layer is exposed to ion implantation which amorphizes certain regions. This allows modifying the refractive index in specific areas to collimate and extract more light from the microLEDs. For example, amorphizing regions near the active region that emits light to act as converging lenses. The implanted amorphous areas with different refractive indexes can alter the light propagation paths to increase extraction and focus.

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Method of fabricating display structures using micro-LEDs that can improve light extraction efficiency, color control and angular output compared to conventional LED displays. The method involves forming individually addressable micro-LEDs by bonding a patterned LED layer to a carrier substrate, then releasing the growth substrate to expose the back side. Electrical contacts are added to the back side and connected to drive circuitry on the carrier. The exposed back side allows efficient light extraction, color conversion layers and optical features to be added.

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Display module that improves luminance and heat emission performance of micro-LED displays. The module contains micro-LEDs on a substrate, with a reflective layer surrounding the micro-LEDs and a light blocking layer on top. The reflective layer captures and redirects light emitted from the micro-LEDs' lateral surfaces to increase efficiency. The light blocking layer prevents lateral light emission. This improves overall luminance by reducing wasteful side light and heat by containing light emission to the front. The layers can be applied via CVD and polished to expose the micro-LED tops.

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LED package with surface textures to improve LED efficiency by extracting more light from the encapsulating layer. The package has microstructures on its surfaces that reduce total internal reflection compared to smooth surfaces. The microstructures can be formed using compression molding with modified molds or sandblasting with selected media. The rough surfaces scatter light better for improved extraction.

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Micro LED display panels having high efficiency pixel structures to improve extraction of light from the LEDs. The micro LED structures have a bottom conductive layer, a light emitting layer, and a top conductive structure. A dielectric layer separates the bottom conductive layer from the light emitting layer. A side arm connects the bottom conductive layer to the bottom of the light emitting layer. This design allows the bottom conductive layer to be used as a reflector to enhance light extraction.

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Micro LED display with high efficiency and resolution. The micro LED design has a vertical structure with a conductive side arm that connects to the bottom layer of the LED, allowing current injection from the side instead of the top. This eliminates the need for a top metal electrode that blocks light extraction. The design also has a composite reflective layer below the LED to enhance light reflection. The vertical micro LED structure achieves high light extraction efficiency for brighter and more efficient displays.

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Electrode assembly of nano-LEDs maximizing light intensity per unit area by increasing the number of nano-LEDs per unit area and light extraction efficiency. The nano-LEDs are positioned between two electrodes with facing surfaces.

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LED mixing cup structures to increase light extraction from micro LED displays. The structures use a diffuser layer adjacent to the LED to scatter light and an angular filter over the diffuser to prevent total internal reflection. These structures confine and redirect light within the cup area to increase extraction before emitting it through the display stack. This avoids losses due to internal reflection and absorption. The angular filter allows light to escape once redirected to steep angles.

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MicroLED display technology with on-packaging components for light concentration, conversion, and filtering to provide a low-cost, easily manufactured microLED display assembly. The assembly uses metal capsules around each microLED pixel to prevent light interference between pixels. The metal capsules have RGB color filters on top and concave surfaces that concentrate light upward.

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Method for fabricating micro-LED modules with improved light extraction efficiency by removing the sapphire substrate after flip-chip bonding to a submount. A buffer layer is used to protect the epitaxial layers during laser lift-off.

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A high light-extraction efficiency light-emitting diode (LED) design that uses asymmetric protruding microstructures on the LED surface to increase light extraction. The protruding microstructures improve light extraction by reducing internal reflection and increasing the escape cone angle. The microstructures can be on the substrate surface, the LED layer surface, or both. They are asymmetric and angled to scatter and redirect light outwards. This boosts the LED's overall brightness and efficiency.

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Increasing the light extraction efficiency from micro-LEDs by modifying the GaN layer to steer emitted light out of the device by exposing specific regions of the GaN layer to ion implantation to amorphize them. The amorphous regions have a different refractive index than the crystalline GaN, so they redirect light rays out of the LED that would otherwise be trapped by total internal reflection. This improves light extraction without physically etching the LED surface.

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A method of manufacturing micro LED display panels with improved light emission efficiency. The method involves forming grooves on a driving substrate using a photoresist layer. The micro LEDs are then positioned in the grooves. This allows the micro LEDs to be recessed into the substrate and increase their light emission utilization.

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Micro LED display that provides high light emission efficiency through better utilization of the LED emitter structures. The display has a substrate with electrode structures connected to circuitry within the substrate. An LED functional layer above the substrate contains isolated LED structures that correspond to the electrode structures. The LED structures can emit light individually. An electrode layer covers the LED layer and micro lenses focus light from each LED structure. This allows each isolated LED structure to be fully used as a pixel emitter, improving light extraction compared to shared LED regions. The isolated LED structures are electrically connected to the substrate electrodes. The display is manufactured by etching openings through the LED layer and substrate, filling them with metal pillars, and depositing the electrode and lens layers.

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Micro-LEDs with improved collimation of light extraction while maintaining high efficiency. The micro-LEDs have a parabolic mesa shape with low aspect ratio, a polished primary emission surface, and an offset light source. The parabolic mesa allows internal reflection of non-collimated light rays to enhance collimation.

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Micro LED display that provides improved light emission efficiency compared to conventional designs. The micro LED display has a substrate with electrode structures connected to circuitry. On top of the substrate is an LED layer with isolated LED structures that correspond to the electrodes. This allows each LED structure to be the full light-emitting region of a pixel. An electrode layer covers the LED layer, and micro lenses sit on top. The isolated LED structures connected to electrodes provide higher efficiency lighting. The manufacturing method involves selectively etching the LED layer to isolate the structures.

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An LED structure for better light extraction in displays by using hexagon shaped LEDs mounted within circular reflective wells. The hexagon shape allows a closer fit to the circular wells compared to square LEDs, increasing light extraction efficiency. The compact fit enables more compact pixel staggering and resolution in displays.

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Micro LED display panel with high light extraction efficiency. The panel has a TFT substrate, bottom electrode, Micro LED chip, top electrode, and protecting layer. The bottom electrodes are reflective type with flanges that surround the Micro LED chips. The flanges are pasted inside the substrate's countersink holes. This prevents light from reflecting back into the Micro LED. The panel has high light extraction efficiency from the front side.

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MicroLEDs with improved collimation of light output by using a near parabolic mesa shape, offsetting the light emitting source from the mesa axis, and a polished reflective primary emission surface. The parabolic mesa shape helps collimation while maintaining extraction efficiency. The offset source position and polished surface enable internal reflection of stray light to further improve collimation. The combination of features provides better collimated light suitable for applications like displays, imaging, and optical communication.

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Micro LED mixing cup structures that enhance light extraction efficiency and reduce TIR losses compared to conventional structures. The mixing cup structures confine and scatter light emitted by the LED to maximize extraction. The structures contain a diffuser layer with scattering particles adjacent to the LED, an angular filter above the diffuser, and optionally a sidewall passivation layer around the LED. These layers redirect and randomize the LED light direction to escape the display stack without TIR trapping.

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A microLED fabrication technique that allows high efficiency, high density microLED arrays. A key feature is forming the bottom contact around the base of the mesa structure rather than as a separate contact layer. This increases light extraction and packing density. The technique involves depositing the contact on the side of the mesa-shaped LED structure, rather than on the top or bottom surfaces. This avoids blocking light emission.

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Micro-LED devices with improved light extraction efficiency. The micro-LEDs have off-axis crystal structures that guide light generated in the active region to exit the device at angles less than total internal reflection. This improves extraction efficiency compared to micro-LEDs with aligned crystal structures that cause light to exit at high angles. The off-axis crystal structures can be achieved through intentional misalignment of the crystal lattice orientation with the device surface.

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Method for improving light extraction efficiency of remote phosphor LED lamps by laser processing the phosphor crystal. The phosphor crystal is ablated with laser to create microstructure arrays on the surface. This roughens the surface to scatter light out more effectively. The laser ablation creates ordered patterns of microstructures on the phosphor crystal surface. This increases light extraction efficiency by allowing more light to escape the crystal instead of being internally reflected back. The patterns can be tailored to optimize light extraction.

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A design and method for a high light-extraction efficiency (LEE) LED that improves the amount of light that can be extracted from the LED. The design uses asymmetric micro-structured elements on the LED substrate or overlayer that protrude into the active LED layers. These elements have angled surfaces that redirect light rays that would otherwise be trapped by total internal reflection in the LED materials. The angled microstructures scatter the trapped rays towards the surface at greater angles where they can escape.

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Micro LED display technology with high light extraction efficiency and low power consumption for use in high-resolution, high-performance image display devices. The micro LEDs have a specific mesa shape with a flat top surrounded by a sloped sidewall. This shape allows more light to escape the LED structure by reducing total internal reflection. The micro LED fabrication involves etching the mesa shape before bonding to a substrate. This provides highly efficient micro LEDs even at very small sizes.

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Micro LED display panel that achieves high front side light extraction efficiency. The panel has a TFT substrate, bottom electrode, Micro LED chip, top electrode, and protective layer. The bottom electrodes are arranged in arrays with flanges around each Micro LED. The flanges extend out from the TFT substrate and reflect light from the bottom back towards the top. This prevents light loss through the substrate. A countersink hole in the protective layer embeds the bottom electrode flanges. The Micro LED chip is transferred onto the bottom electrode. The flanges reflect light towards the top and prevent loss through the substrate.

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Method of fabricating a micro-LED module by mounting a micro-LED on a submount and removing the sapphire substrate to prevent light extraction efficiency loss. The method uses a buffer layer between the micro-LED and submount to absorb laser energy during sapphire removal and protect the LED and submount from damage.

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Micro light emitting diodes (LEDs) with photonic crystal columns extending through the transparent semiconductor layer to increase the directionality of emitted light. The photonic crystal columns inhibit light propagation in certain directions to reduce light divergence. This improves extraction of light from the LED and prevents absorption and overheating. The columns are arranged in a 2D array and grown in the semiconductor layer by etching and crystal growth techniques.

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Encapsulating micro LED displays to protect and enhance the performance of the LEDs. The encapsulation structure is a transparent plate on top of the micro LED array, with vias above each LED filled with a UV resin microlens that covers the LED. This protects the LEDs and allows control of the light emitted.

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Micro-LEDs with improved collimation of light output. The micro-LEDs have a near-parabolic mesa with a low aspect ratio and a polished primary emission surface. The low aspect ratio mesa allows parasitic light rays to be reflected back inside the device instead of being extracted. This improves collimation. The polished emission surface aids internal reflection. The offset light emitting source also contributes to collimation. The design compromises extraction efficiency for better collimation.

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MicroLEDs with improved collimation of light output through optimized mesa structures and emission surfaces. The microLEDs have a truncated parabolic mesa with a low aspect ratio, a reflective region between the mesa and emission surface, and an offset light source. This allows internal reflection of parasitic rays back into the substrate to improve collimation while still maintaining good extraction efficiency.

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