Micro-LED displays face significant optical challenges at the pixel level, where emission angles can exceed 120 degrees and cross-talk between sub-pixels impacts color purity. Current designs achieve only 20-30% extraction efficiency, with substantial light loss occurring at material interfaces and through total internal reflection within the LED structure.

The fundamental challenge lies in maximizing light extraction and directionality while maintaining the ultra-small form factors required for high-resolution displays.

This page brings together solutions from recent research—including integrated micro-lens arrays, reflective cavity designs, wavelength-selective mirrors, and crystalline waveguide structures. These and other approaches focus on practical manufacturing methods while addressing both efficiency and color quality requirements for next-generation displays.

1. 650 nm emitting InGaN red micro-LEDs with ITO n-electrodes

cesur altinkaya, rawan jalmood, mohammed a najmi - Institute of Physics, 2025

Abstract InGaN red micro-LEDs were fabricated with indium tin oxide (ITO) and metal n-electrode designs. Micro-LEDs ITO electrodes achieved a peak on-wafer external quantum efficiency of 2.1% (at 1.25 A/cm2) wall-plug 1.7% 0.64 A/cm2), representing 1.6 times 1.5 improvements compared to metal-based electrodes. Improved performance was attributed the transparency ITO, enabling light extraction, while block emission. Both configurations low leakage current density ( 107 high emission wavelength around 650 nm. These results represent strong potential for low-power consumption required/area-limited AR/VR applications.

2. MicroLED Display with Brightness-Adjustable Pixels and Scattering Plate for Enhanced Image Smoothness

THALES SA, 2025

Anti-aliasing technique for microLED displays that improves image smoothness by adjusting brightness levels within individual pixels. The technique uses microLED displays with each pixel containing a group of three differently colored microLEDs covered by a scattering plate. By controlling the brightness of the individual microLEDs inside a pixel, it allows gradual color transitions between pixels for smoother images compared to using fixed color filters.

3. Stamp with Shape Memory Polymer Nanotips for Micro-LED Transfer and Placement

POSTECH RESEARCH AND BUSINESS DEVELOPMENT FOUNDATION, 2025

Transferring micro-LEDs using a stamp with shape memory polymer nanotips to pick up and release the devices. The stamp has nanotips that can selectively adhere to the micro-LEDs due to shape memory properties. The nanotips heat to a critical temperature, contact the LED, press to attach, cool below critical temp, align on substrate, then heat again to transfer. This allows precise pickup, placement, and repair of micro-LEDs.

US2025144816A1-patent-drawing

4. MicroLED Array Integration for Compact Light Sources in AR/VR Devices

LUMILEDS LLC, 2025

Using microLED arrays in applications beyond just displays, like augmented reality (AR) and virtual reality (VR) devices, by integrating compact light sources made of microLED arrays into these devices. The microLED arrays provide smaller, more efficient light sources compared to traditional light sources. This allows for improved AR/VR devices with better display brightness, contrast, and power efficiency.

5. MicroLED Display with Interstitial Blocking Regions for Crosstalk Mitigation and Enhanced Brightness

SAMSUNG ELECTRONICS CO LTD, 2025

MicroLED display to prevent crosstalk and improve brightness by inserting blocking regions between each color conversion region. The blocking regions prevent light from one subpixel leaking into adjacent subpixels, reducing crosstalk. This is achieved by forming the microLED structure with separate pores for the color conversion regions and additional blocking regions in between. The color conversion material is filled in the color conversion pores and the blocking regions are left empty. This prevents light from one subpixel leaking into adjacent subpixels, reducing crosstalk.

US2025143036A1-patent-drawing

6. All‐GaN‐Based Monolithic MIS‐HEMT Integrated Micro‐LED Pixels for Active‐Matrix Displays

yuta furusawa, wentao cai, h s cheong - Wiley, 2025

An allGaNbased monolithic activematrix microLED system that integrates metalinsulatorsemiconductor highelectronmobility transistors (MIS HEMTs) with lightemitting diodes (LEDs) is demonstrated. The proposed structure employs direct electron injection from the 2D gas (2DEG) in a HEMT, serving as ntype layer, into quantum wells of LEDs. A 2HEMT1LED pixel configuration fabricated one epitaxial growth, enabling precise control LED light output through combination select and drive HEMTs. achieved maximum optical density 0.5 Wcm 2 . 2 matrix constructed row column lines connected via HEMTs, demonstrating capability for individual control.

7. Heterogeneous and Monolithic 3D Integrated Full‐Color Micro‐Light‐Emitting Diodes via CMOS‐Compatible Oxide Bonding for µLEDoS

hyun soo kim, juhyuk park, woojin baek - Wiley, 2025

Abstract Microlight emitting diode (LED) based LED on silicon (LEDoS) is a promising candidate for nextgeneration AR and VR displays due to superior pixel performance potential high resolution. Traditional RGB pixels are placed single plane, which limits the To overcome this, vertically stacked using heterogeneous monolithic 3D integration (M3D) have been explored. However, previously reported vertical LED not considered heat dissipation capability of pixels, indeed important in future micro displays, utilized materials incompatible with standard CMOS processes, further limiting their practicality LEDoS. The critical regions constraint, bonding medium, typically organic polymer materials. Therefore, handle issue, fullcolor LEDs demonstrated oxide (SiO 2 ) yttrium (Y O 3 ), as mediums. These CMOScompatible offer thermal conductivity at least 10 times higher than conventional polymers. InGaN/GaN blue bonded oxides show improved management, leading external quantum efficiency (EQE) better color characteristics, including narrower full width half maximum (FWHM) purity. ... Read More

8. Pixel Structure with Integrated Light-Emitting and Light-Sensing Subpixels and Electrode Configuration

SEMICONDUCTOR ENERGY LABORATORY CO LTD, 2025

Display apparatus with a pixel structure that allows combined light emission and light sensing in each subpixel. The pixel has subpixels, at least one of which has a light-emitting and light-receiving device instead of a regular light-emitting device. This allows the display to emit light and also detect light in the same subpixel. This enables multifunctionality like displaying an image and sensing light simultaneously. The light-emitting and light-receiving device has a structure with electrodes for emitting and sensing light.

9. Display Device with Substrate Opening and Etch-Selective Grooves for Component Integration

SAMSUNG DISPLAY CO LTD, 2025

Display device with integrated components in the display area and an opening for other components. The display has a substrate with an opening surrounded by a display area. Grooves are formed between the opening and display using a layer with different etch selectivity compared to the main insulating layer. This allows etching grooves without damaging the display elements. It enables integrating components like sensors or cameras into the display while preventing contamination of the display area.

US2025127016A1-patent-drawing

10. Transfer Stamp for Micro-LEDs with Protruding Adhesive Grooves and Thermal Conductivity Buffer Layer

LG DISPLAY CO LTD, 2025

A light-emitting element transfer stamp and manufacturing method for pickup and placement of micro-LEDs without complex spring structures or high voltages. The stamp has adhesive layers in grooves that protrude above the stamp. This allows selective picking up of micro-LEDs from a growth substrate by adhesion force, then releasing to transfer onto a target substrate. A passivation layer prevents sticking between layers. The stamp material has thermal expansion matching the LED substrate. The stamp has a buffer layer with thermal conductivity between the stamp and a heater wire. This enables local heating for stamp deformation and release of the LEDs. The stamp structure allows micro-LED transfer without complex springs or high voltages.

11. Stacked Optical Component Packaging with Vertically Aligned Interposers Featuring Integrated Lenses and Reflectors

TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD, 2025

Packaging design for optical interconnects that allows vertical transmission between stacked optical components using integrated lenses and reflectors. The packaging involves bonding optical interposers and optical packages vertically aligned with lenses between them. The reflectors in each interposer are aligned vertically to transmit light between the packages. This enables vertical optical transmission between stacked optical components using integrated lenses and reflectors instead of through-the-substrate techniques.

12. Compact Optoelectronic Device Assembly with Insulated Semiconductor Side Walls and Rear Contact Access

OSRAM OPTO SEMICONDUCTORS GMBH, 2025

Arrangement and method for simplified assembly of compact optoelectronic devices like microLED displays with improved uniformity and reduced tilt. The devices have small-sized semiconductor components with side walls insulated and absorbing to prevent tilt. They are mounted on a carrier with a transparent output element and connected via an insulating layer. The components' contacts are electrically accessed from the rear. This allows easier assembly of small-pitch arrays with uniform radiation and reduced crosstalk. The method involves applying the components, insulation, and output element on a carrier, then connecting the contacts.

US2025126953A1-patent-drawing

13. Micro LED Display Panel with Symmetrical Void Surrounding LED in Prism Layer

WUHAN CHINA STAR OPTOELECTRONICS SEMICONDUCTOR DISPLAY TECHNOLOGY CO LTD, 2025

Micro LED display panel design to improve display quality by reducing aberrations and crosstalk between subpixels. The key idea is to surround the LED chip with a symmetrical void in the prism layer. This ensures equal distances between the LED and void in the transverse and oblique directions. The symmetry allows the light rays to reflect identically in both directions, preventing asymmetric focal planes and reducing astigmatism. It also prevents light crosstalk between subpixels by reflecting the rays back into the LED instead of spreading them.

US2025126913A1-patent-drawing

14. Light Emitting Module with Multi-Region Diffusive Cover and Lens Arrangement

NICHIA CORP, 2025

Light emitting module with reduced stray light on the irradiation surface. The module has a lens over the light source, and a cover over the lens. The cover has three regions: an inner region where light from the lens enters, a middle region around the inner region with higher diffusion, and an outer region. This configuration reduces stray light by having the cover's middle region with higher diffusion surrounding the inner region where light from the lens enters, preventing light from escaping sideways.

US2025123538A1-patent-drawing

15. Micro LED Display Panel with Integrated Epitaxial Micro Lens Structures

JADE BIRD DISPLAY LTD, 2025

Micro LED display panel with integrated micro lenses to simplify manufacturing. Each micro LED structure has a first type epitaxial layer, a light emitting layer, and a second type epitaxial layer. The second type epitaxial layer has an integrated structure containing both a micro lens and a bottom layer. This eliminates the need for a separate micro lens manufacturing step.

16. Optical Laminate with Recessed Light Extraction Layer and Air Gap Formation

NITTO DENKO CORP, 2025

An optical laminate with improved light extraction. The laminate has a light extraction layer with recessed areas, covered by two sheets separated by adhesive. The recessed areas form air gaps between the sheets. The laminate also optionally has a thin porous layer between the light extraction layer and the adhesive. The air gaps and porous layer lower the refractive index in certain regions, improving light extraction compared to solid adhesive.

US2025123437A1-patent-drawing

17. Transparent Display Device with Stacked Reserve Sub-Pixels and Transparent Electrode Configuration

LG DISPLAY CO LTD, 2025

Transparent display device with improved resolution and repair capability. The display has sub-pixels containing red, green, and blue LEDs, along with a reserve sub-pixel with stacked red, green, and blue LEDs. If any LED in a normal sub-pixel fails, the reserve LEDs can replace them. Stacking the reserve LEDs reduces area compared to parallel LEDs. The reserve LED electrodes are transparent to allow light from lower LEDs to escape. This allows repair and area savings while maintaining light output.

18. Optical Stack with Polarization-Selective Blue Light Reflection and Transmission for Blue-LED Backlit Displays

3M INNOVATIVE PROPERTIES CO, 2025

Optical stack and backlight design for high dynamic range displays using blue LEDs instead of white backlights. The optical stack reflects blue light with a specific polarization and transmits orthogonal polarization. This allows collimated blue light with low divergence to be used in displays with blue-only backlights. The stack has high reflection in the blue range for one polarization and high transmission for the orthogonal polarization. This preserves blue light while suppressing cross-talk between pixels in blue-only displays. The collimated blue light can be generated by blue LEDs and reduces the need for color filters in the display.

US2025123517A1-patent-drawing

19. MicroLED Display Containers with Variable Diameter Profiles for Enhanced Light Coupling

TECTUS CORP, 2025

MicroLED displays with containers for color conversion materials like quantum dots that have varying diameter profiles along their length. This shape provides better light coupling efficiency compared to cylindrical containers. The containers have a waist section with a smaller diameter than the end faces. This design helps collect more emitted light from the LED into the display's acceptance angle. It balances couplings between LED, quantum dots, microlens, and display acceptance cone for improved overall display performance.

US2025126938A1-patent-drawing

20. Display Module with Aligned Micro-Lenses and Interstitial Converging Lenses

YUNNAN INVENSIGHT OPTOELECTRONICS TECHNOLOGY CO LTD, 2025

Display module with micro-lenses to improve brightness of microLED displays. The display module has a color filter layer with light-filtering sections, and a micro-lens layer with converging lenses. Each micro-lens is aligned with a color filter section. Gaps are provided between adjacent micro-lenses. Additional converging lenses are placed in these gaps to capture light from the gaps and focus it. This improves brightness by reducing light spread and improving convergence.

21. Miniaturized Planar Light Source with Collimating System and Polarization Conversion for Displays

22. Chip Package with MicroLED-Based Optical Interconnects Using Waveguide-Coupled Photodetectors

23. Monolithic MicroLED Display with Adjacent Quantum Dot Color Conversion Pixels

24. Transparent Display Utilizing Substrate Guided Optics and Switchable Bragg Gratings with Angular Interval Division

25. Photo Detecting Device with Integrated Tunable Wavelength Light Emitting and Photoelectric Conversion Elements on a Single Substrate

Achieving stunning visuals with micro-LED displays requires precise light control, and advancements in micro-LED optical modules are crucial.  These modules offer a variety of solutions, like integrated quantum dot technology and optimized pixel designs, to deliver rich and pure colors.

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