High-Resolution Micro-LED Display Production

Monolithic microLED display fabrication method to avoid organic material residue in vias that can cause defects. The method involves isolating the LED with a base layer before processing the OTFT. This allows consistent etching of vias through the isolated base layer to connect the LED and OTFT without organic material filling. After OTFT processing, a final via is etched through both the base layer and any passivation layer to complete the connection. This avoids organic material deposition during OTFT processing that can impede subsequent passivation layer deposition.

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Flexible thin film GaN-based nanocolumn LED array micro-display device and manufacturing method. The device has a flexible substrate with a mask having periodic openings. GaN LED nanocolumns are selectively grown inside the openings using MOCVD. The LEDs have cylindrical or hexagonal shapes. The nanocolumn LED array is covered by a transparent conductor and flexible material. Electrodes are added on the flexible layer. This allows flexible, high resolution, high efficiency LED microdisplays with improved yield compared to traditional top-emitting microLEDs.

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Micro LED display device and manufacturing method that prevents moisture and dust intrusion to improve reliability. The micro LED display has a pixel layer with individual micro LEDs facing the circuit substrate. A support structure extends from the substrate to the pixel layer and protrudes above it. This forms a space between the support and pixel layer. A connection layer is filled in this space and covered by a protection layer. This enclosure around the pixels prevents moisture and dust from reaching the LEDs and degrading their performance.

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Preparing smaller-sized micro LED chips for higher resolution displays by patterning a mask on the second semiconductor layer and etching to limit chip size. This involves forming a patterned silicon oxide mask on the second semiconductor layer, using the mask to deposit a transparent conductive layer in certain areas and etch the second semiconductor layer in others. This creates micro LED chips with smaller pixel pitches and higher resolution.

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Display module with improved bonding accuracy for micro LEDs. The module has a substrate with a region around the pixel area having higher surface energy. When bonding micro LEDs to the substrate electrodes, an adhesive layer is temporarily cured to move the excess adhesive from the pixel area to the higher surface energy region. This reduces thickness variation and misalignment of the micro LEDs compared to uniform adhesive. The higher surface energy area helps hold the micro LEDs in place during curing. The thinner adhesive between the electrodes reduces voids and gaps.

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Micro LED display device with simplified manufacturing by using a transparent substrate with pre-transferred micro LEDs, and forming the TFT electrodes on top using an organic TFT layer instead of transferring the micro LEDs onto TFT electrodes. This allows easier micro LED transfer and simplifies the manufacturing process compared to conventional micro LED displays. The device has a transparent substrate with exposed micro LED anode and cathode electrodes, a signal supply line layer on top, and an organic TFT layer with driving transistors on the supply lines.

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Integrated display wafer and preparation method for low-cost, high-performance microLED displays with improved yield and reduced cost compared to conventional microLED displays. The method involves integrating the microLED chips, electrodes, and isolation layers on a temporary substrate, then transferring the entire integrated wafer to a final display substrate. This eliminates the need for individual microLED chip transfer and testing, reducing defects and costs. The integrated wafer has layers of microLED chips, isolation layers, electrodes, and a temporary substrate.

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A method for selectively transferring microLEDs to fabricate displays with higher yield and lower cost compared to traditional methods. The method involves covering the microLED wafer with an adhesion layer, depositing the backplane on the adhesion layer aligned with some exposed microLEDs, then removing the backplane with those microLEDs to a display substrate. This allows selective transfer of working microLEDs without individually moving them. The adhesion layer prevents damage to the microLEDs and backplane during removal. This reduces transfer errors compared to pick-and-place or adhesive films. The display can have monolithic integration of microLEDs and backplane on the same substrate, but allows repair of defective microLEDs by selective transfer.

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MicroLED display with on-chip integrated transistor driver circuit to reduce integration complexity and manufacturing cost compared to bonding MicroLED wafers to separate thin film transistor backplanes. The display structure has a pixel array with each pixel containing a MicroLED chip above the substrate. The MicroLED chip has layers like buffer, N-GaN, MQW, P-GaN, and transparent electrode. The transistor driving circuit is integrated into the first packaging layer covering the MicroLEDs. The transistors are oxide thin film transistors integrated on-chip. This eliminates the need for separate backplane bonding and alignment steps, simplifying manufacturing.

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Micro LED manufacturing method that efficiently implements a structure connecting the pixel and transistor elements, and promotes miniaturization by reducing the thickness. The method involves forming patterns, pixels, upper electrodes, lower electrodes, and protective support layers. The upper electrodes connect pixels in the same row/column, and via holes expose them. The lower electrodes connect pixels perpendicularly. This allows efficient pixel-to-transistor connection without stacking. The protective support surrounds the pixels and electrodes. The method reduces thickness by exposing lower pixel surfaces and forming lower electrodes there.

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Method to manufacture microLED displays with reduced production cost and improved yield compared to existing methods. The method involves using alkyl precursors to grow semiconductor layers for microLEDs directly on a display substrate without the need for a separate sapphire or other growth substrate. This eliminates the high-temperature, high-cost sapphire transfer step. The alkyl precursors allow epitaxial growth on the display substrate using lower temperatures. The alkyl precursors can be converted into the corresponding semiconductor materials during growth. The alkyl-assisted growth also allows tuning of composition and doping levels to optimize LED performance.

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A method for manufacturing a micro LED character display chip with improved isolation between the control metal wires and the LED sidewalls. The method involves depositing a thicker silicon dioxide insulating film on the LED sidewalls compared to the sidewall depth. This provides better electrical isolation between the metal wires and LED sidewalls when crossing over. The thicker insulating film prevents short circuiting of the control wires and LEDs.

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Preparing microLED array substrates without using photoresist to avoid issues like contact failures and damage during etching. The method involves covering the anode and cathode contact layers with hardmask layers instead of photoresist. These hardmask layers are patterned to define the pixel areas. After patterning, the substrate is bonded and the original substrate removed. The cathode hardmask is then etched to connect the anode pattern. This eliminates the need for photoresist and subsequent cleaning, preventing contact issues and sidewall damage.

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Method for manufacturing LED displays with micro/nano LEDs that allows easy assembly of small LEDs on a substrate. The method involves forming a base circuit on the substrate, covering it with an electrode layer, forming an insulating layer over the entire area, creating a trench-shaped LED array area in the insulating layer, and supplying LEDs in fluid form. Applying voltage to the electrodes aligns the LEDs in the array. The insulating layer is removed to expose the LED contacts, which are then connected to the electrodes. This allows precise positioning of micro/nano LEDs without physically transferring them.

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Micro LED display panel with integrated multi-color LED pixels to improve efficiency and reduce production cost compared to assembling monochrome LEDs. The method involves forming a stack of layers containing different color LED materials on a substrate, patterning them to expose the bottom conductive layer, then selectively etching to expose sidewalls and form separate pixels with stacked LED structures. This allows integrated multi-color pixels in each display area.

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Wafer-level full-color LED display device with improved yield and reliability by eliminating issues with conductive lines breaking during manufacturing. The device is fabricated by alternating LED structures in rows and columns with trenches between them. Insulating layers are filled in the trenches to level the LED structures and fill the height difference. Circuit layers are then built on top of the leveled structures. This prevents conductive lines from breaking as they climb over the trench steps during manufacturing.

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Simplifying the process of making ultra-high resolution microLED displays by using ion implantation to isolate pixels instead of complex photolithography steps. The method involves forming a metal bump array on the microLED epitaxial wafer using electroplating. Then, a photoresist pattern is used to mask the metal bumps during ion implantation to isolate the pixels. This avoids the need for multiple steps of photolithography and etching for pixel definition. The metal bumps also serve as seed layers for electroplating.

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Manufacturing microLED devices using a self-alignment process that addresses issues like mask intolerance, pattern shrinkage, sidewall damage, and protection layer opening problems during microLED fabrication. The method involves several steps: 1. Forming a protection layer on the microLED structure. 2. Etching the microLED structure using dry etching techniques like ICP. This shrinks the photoresist mask and introduces sidewall damage. 3. Removing the photoresist mask. 4. Forming a self-aligned dielectric layer on the microLED structure using selective deposition techniques. This is done by selectively depositing the dielectric layer only on the microLED sidewalls, leaving the top and bottom surfaces exposed. This is achieved by using a mask with openings that align with the microLED sidewalls, but not the top and bottom surfaces. This self-aligned

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Active full-color MicroLED display device with improved yield and manufacturing efficiency by integrating the MicroLED array and driver circuitry on a single silicon substrate instead of transferring pre-made MicroLEDs. The device has a silicon substrate with an epitaxial layer of LED material on one side. MicroLEDs are formed on the epitaxial layer by etching. A pixel driving circuit is prepared on the other side of the substrate. This avoids the complex and low yield microtransfer method of attaching pre-made MicroLEDs to a display backplane.

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HEMT (high electron mobility transistor) integrated MicroLED backplane for displays that avoids the challenges of transfer bonding and mass transfer methods. The HEMT and MicroLED devices are directly integrated at the epitaxial growth stage rather than bonding or transferring separately. This allows HEMT and MicroLED devices to be grown on the same wafer using the same epitaxial growth equipment. The HEMT provides active pixel control for the MicroLEDs, addressing challenges like current-induced wavelength shift and nonlinear grayscale expansion. The integrated HEMT-MicroLED backplane enables efficient, reliable, and scalable manufacturing of high-resolution, high-refresh-rate MicroLED displays without the complexities and limitations of transfer bonding or mass transfer techniques.

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LED display with stacked microLEDs and manufacturing method to improve brightness and resolution compared to horizontally arranged microLEDs. The method involves aligning vertical stacks of microLEDs between electrode layers so they emit parallel to the substrate. This allows more microLEDs per pixel area. Connection electrodes are formed at each end to connect the vertical stacks to the electrode layers. This enables simultaneous lighting of all stacked microLEDs.

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Preparing a high-brightness micro-LED display matrix with vertical structure for medium-sized displays. The method involves integrating the micro-LEDs on a single chip instead of transferring them. The micro-LEDs are grown on a wafer with electrodes. After patterning, the micro-LEDs are bonded to a second substrate with drivers. This allows higher pixel density and current capacity compared to transfer methods. The vertical structure with series-connected micro-LEDs and reflective electrodes improves brightness. The single-chip integration enables medium-sized displays with ultra-high brightness.

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Integrated LED chip with improved reliability and yield by growing micro LED epitaxial wafers in each micro LED region surrounded by passivation. This avoids etching to define micro LED areas and reduces damage. The micro LED wafers are mesa etched with bosses. Driving structures are placed next to the mesas to avoid blocking light. Electrodes connect between the mesas and driving. This simplifies chip preparation compared to mass transfer or monolithic bonding.

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A simplified and controllable method for preparing high-quality MicroLED chips with improved efficiency and yield. The method involves a direct lift-off process to transfer the LED structure onto the target substrate. It involves growing the LED structure on a temporary substrate, coating a photoresist layer over it, patterning the photoresist to expose specific areas, etching the LED structure selectively in the exposed areas, and then lifting off the remaining LED structure on the unetched areas onto the target substrate. This avoids complex processes like epitaxial regrowth or wafer bonding.

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Forming MicroLED pixel units with high integration and transfer efficiency by selectively etching trenches around the pixels without damaging the underlying material. The method involves etching trenches around the pixel area of a multi-layer semiconductor LED structure while leaving the pixel area untouched. The trench depth is 20-95% of the LED thickness. After etching, the LED is bonded to a substrate with the trenches facing up. The growth substrate is removed and the remaining LED in the trenches is etched away to isolate the pixels. This allows high-resolution pixelization and transfer without damaging the LED material.

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Micro LED display chip, manufacturing method, and device that avoids brightness non-uniformity and mura issues in micro LED displays. The method involves growing the micro LED epitaxial layer on a patterned substrate with protrusions and recesses. The LEDs are formed in the recesses aligned with the protrusions. This ensures consistent LED quality, brightness, and efficiency since the LEDs grow in the same crystal orientation as the recesses. The LED array made on the patterned substrate is then connected to a backboard to create the micro LED display chip.

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Method to manufacture micro LED displays with higher yield by enabling easy replacement of defective chips and preventing wire disconnection during curing. The method involves transferring micro LED chips to an intermediate substrate, inspecting them, replacing defective chips, fixing them, wiring them, then transferring only the good chips to the final rear substrate. This allows fixing and wiring defective chips separately from the final display, preventing damage to the rear substrate if a chip needs replacement. The wiring process involves etching and passivation steps to prevent wire disconnection during curing.

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Manufacturing method for micro LED displays that reduces defects and improves yield by preventing wire disconnection during assembly. The method involves transferring micro LED chips to an intermediate substrate, inspecting them, replacing defective chips, fixing them, wiring them, and then transferring only the good chips to the final substrate. The wiring step uses a passivation layer with controlled thickness to prevent wire disconnection during curing. The passivation layer partially covers the micro LED edges, but the top electrodes extend slightly higher. This spacing prevents wire disconnection as the passivation deforms during curing.

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Efficient and accurate transfer of micro LED chips onto a driving substrate for displays using a wafer-level preprocessing and packaging technique. The method involves extracting micro LED crystals from a wafer, placing them into square tubes, arranging the tubes in a pixelated array, cutting the array into sheets, and attaching the sheets to a driving substrate. This allows large numbers of tiny LEDs to be precisely transferred and assembled into displays using a wafer-level packaging process instead of pick-and-place.

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Micro LED display module with improved transfer precision, reduced defects, higher throughput, and better contrast. The module has a substrate with positioned recesses to match the micro LED chips. This avoids offset during transfer and improves yield. The recesses also prevent crosstalk between pixels. The module uses quantum dot materials for full color micro LEDs with better purity. It has a transparent black matrix to improve contrast. The micro LEDs are matched to the recesses with beveled edges to improve brightness. The display uses only blue micro LEDs for consistent brightness. The black matrix is applied first then transparent encapsulation avoids brightness loss.

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Light emitting assembly with micro-LEDs that allows efficient transfer printing without yield loss. The micro-LED structure has bridging arms connecting to a supporting substrate. The arms are thinner than the surrounding dielectric layer on the mesa surface. During transfer, the thinner arms break cleanly leaving a small residue on the LED side wall. This avoids remaining arm fragments that can impede operation. The thin arms require less force to separate compared to equal width arms, improving yield. The thinner arms also allow higher density packing of micro-LEDs on the substrate without collisions.

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A monolithic micro LED pixel design that enables efficient manufacturing of high resolution micro LED displays. The design involves forming multiple micro LED subpixels on a sacrificial substrate, then transferring the entire array onto a handling substrate. This allows further processing of the sacrificial substrate side while protecting the LED surface. A planarizing dielectric layer is added to align the LED surface. The sacrificial substrate is removed, leaving etched sidewalls surrounding the LEDs. This allows dense packing of micro LEDs without cross-talk. The handling substrate can then be removed for final display assembly. The monolithic pixel design enables high yield manufacturing of large micro LED arrays.

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Micro LED display technology with improved alignment precision for bonding the LED chip and CMOS driving chip. The method involves growing the LED epitaxy on a wafer, then adding insulating and electrode layers on the LED side. The LED chips are separated with windows in the insulating layer exposing the active LED layer. This allows bonding the LED chips to CMOS chips using electrode columns from the CMOS side and windows from the LED side. The columns connect through the insulating layer to the exposed LED layer. This avoids precise alignment between the tiny LED and CMOS pixels.

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Preparing microLED chips with improved area utilization, current uniformity, and yield compared to conventional methods. The process involves etching mesas into the epitaxial wafer to expose the inner semiconductor layers. Metal electrodes are deposited on the mesas and outer layers. A metal grid connects adjacent mesas to the peripheral electrode. This maximizes wafer utilization by reducing the area between mesas. The grid collects current from the outer electrode. The outer electrode contacts are protected by a passivation layer with contact holes.

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Full-color LED display using micro-nano LED elements to improve brightness and efficiency. The display has sub-pixels with multiple micro-nano LEDs emitting the same color aligned on electrodes. This increases area vs traditional stacked nano-columns. The micro-nano LEDs have a longer length than thickness. The display is made by self-aligning micro-nano LEDs on electrodes in sub-pixel spaces. This avoids pick-place assembly and separate electrode layers. The micro-nano LEDs are contacts to upper and lower electrodes. The display is driven with assembly voltage to align the LEDs. The sub-pixels use micro-nano LEDs of the same color to improve brightness and efficiency compared to stacked nano-columns.

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Manufacturing process for microLED displays with integrated RGB pixels that improves on existing methods by reducing complexity, improving efficiency, and enabling miniaturization compared to alternative solutions like quantum dot conversion or light path integration. The process involves growing an LED structure with a stack of quantum wells containing indium gallium nitride (InGaN) layers. The In content in the InGaN quantum wells is adjusted to tune the emission wavelength of each color (red, green, blue) separately. This allows integrated RGB pixels to be made using just one type of LED material, avoiding the need for quantum dots, complex light path integration, or film transfer.

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A method to mass transfer microLEDs from their growth substrate to a display substrate with circuitry and pads for attaching the microLEDs. The method involves flipping the microLED-containing substrate, bonding the microLEDs to the display substrate using heat, then separating the flipped substrate. This allows transferring many microLEDs at once without individually picking them up. The display substrate has driving circuitry and pads for attaching the microLEDs. The separated microLED substrate is reflowed to fix the microLEDs in place. This avoids the mass transfer problem of picking up and placing many tiny microLEDs.

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Active microLED display with improved yield and efficiency by integrating the microLED and drive electronics. The method involves forming a microLED epitaxial layer on a substrate, adding electrodes on one side far from the epitaxial layer, creating driving circuitry on the electrode side, stripping the substrate, etching the epitaxial layer based on electrode positions, and adding final electrodes on the microLED units. This directly forms active microLED display units without separate microLED and drive substrates.

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Micro LED display panel with individually addressable multi-color pixel units. The display panel has a matrix of microscopic pixel units, each containing multiple stacked LEDs of different colors. The pixel units are fabricated by selectively etching layers in a stack structure to expose sidewalls and create isolated LEDs. This allows efficient, high resolution micro LED displays with individual color control in each pixel.

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LED assembly with vertical micro LED alignment that improves light efficiency, quantity, and integration compared to horizontally aligned micro LEDs. The vertical alignment is achieved by inserting micro LEDs into through holes in a substrate. This allows the LEDs to be aligned and fixed in an upright position without overlapping electrodes. It also enables higher packing density and better light extraction as the LEDs emit perpendicular to the substrate surface. The alignment process involves suspending the micro LEDs and flowing them into the through holes.

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Efficient manufacturing method for multicolor micro LED displays that avoids the challenges of transferring and interconnecting large numbers of micro LEDs. The method involves bonding the micro LED epitaxial layers directly onto the driving circuit chips during fabrication. This is done by sequentially bonding and removing the LED epitaxial wafers from the driving chip wafer to form a multilayer structure with the LED layers bonded to the circuit chips. This enables efficient fabrication of multicolor micro LED displays by eliminating the need for separate LED and driver wafers and subsequent transfer steps.

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A manufacturing method for high-precision, high-yield Micro-LED displays with improved transfer efficiency and light control. The method involves transferring multiple epitaxial wafers onto a temporary substrate, forming metal columns between adjacent LEDs, encapsulating each LED and column with a pixel limiting material, and adding a nanowire mesh layer between the limiting material and substrate. This prevents warping of the LED stack during transfer and improves bonding strength. The assembled Micro-LEDs are then transferred to the final display substrate.

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Manufacturing method for micro LED displays that enables direct bonding of the LED dies to the backplane without the need for interposer or transfer substrates. The method involves laser ablation to remove the LED dies from their growth substrate and then bonding the ablated LEDs directly to the backplane using a single bonding structure per LED. This allows high yield, high accuracy transfer of both horizontal and vertical LED structures without needing additional carriers. The laser ablation is cooled with nitrogen below 25°C to prevent damage.

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Method to manufacture high-quality micro LEDs with improved reliability and brightness compared to conventional methods. The key steps are: growing the micro LED structure in a sequence of porous and non-porous layers, forming electrical contacts on the porous layers, and passivating the exposed non-porous layers. This avoids dry etching damage to the LED structure. The porous layers can be porous DBRs with alternating porous and non-porous layers to tune the refractive index. The non-porous layers provide electrical isolation.

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A pixel unit for displays with a micro LED emitter and integrated driver IC to reduce wiring complexity and improve yield. The pixel unit has a micro LED with electrodes, a photoresist layer around it, and a transparent shell encapsulating the components. The driver IC has solder pads on its backside. Electrical connection sheets and pads connect the IC pads to the micro LED electrodes. The shell exposes the top surfaces of the components. A transparent conductive film on the shell electrically connects them. This allows electrical connection to the micro LED and IC without wires inside the shell.

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Micro LED display chip with improved luminous efficiency and preparation method. The chip has micro LED units with a reflective layer on the sidewall instead of the top surface. This avoids light crosstalk between pixels and improves extraction. The reflective layer is formed by etching from the sidewall of the stepped micro LED structure. The etching is done without a mask since the stepped shape provides positioning. This saves process steps compared to etching from the top.

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Manufacturing method for high brightness, small spacing LED displays with improved brightness and reduced manufacturing complexity compared to conventional LED displays. The method involves growing LED chips with specific bandgaps on a wafer, forming transparent conductive layers on them, etching mesas, and adding electrodes. Then insulating reflective layers are deposited, followed by high-reflection metal layers. The substrates are ground to thin them. After testing and sorting, the resulting LED chip groups are packaged. This provides higher brightness by using ODR (omni-directional reflector) structures with insulating reflective layers and high-reflection metal layers, while reducing manufacturing complexity by using thin substrates and simplified pixel layout.

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MicroLED display device with reduced optical crosstalk and improved efficiency by using a unique device structure. The microLED display is fabricated by a simplified process compared to adding black matrixes. The structure has reflective walls around each pixel's mesa that direct emitted light outwards. This reduces crosstalk between pixels. Metal electrodes cover the reflective walls. The device has a substrate, light-emitting element, reflecting element, and metal electrodes. The light-emitting element is the normal LED structure. The reflecting element surrounds it with a similar LED structure to form a mesa. The metal electrodes connect to the normal LED. The reflective walls around the mesa redirect emitted light away from adjacent pixels.

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Micro-LED display manufacturing method and micro-LED display that enables mass production of micro-LED displays by integrating the micro-LEDs and active matrix TFTs on the same substrate. The method involves forming the micro-LEDs with multiple subpixels and wavelengths on the substrate, then integrating TFTs and other display elements without transferring the micro-LEDs. This allows fabricating the micro-LED display in a monolithic process.

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Display module manufacturing method to improve alignment accuracy and efficiency of micro LED transfer for displays. The method involves bonding the micro LED epitaxial structure to the display backplane using intermediate metal layers. This eliminates the need for precise alignment during mass transfer of individually fabricated micro LEDs. The micro LEDs are patterned and separated from the bonded epitaxial structure. The bonding and patterning steps can be done using standard semiconductor processes.

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