Native red

Researchers at the The University of Osaka, in collaboration with Ritsumeikan University have shown how growing europium-doped gallium nitride (Eu-doped GaN) on a semipolar crystal plane dramatically improves red light emission. 

The researchers say that EU-doped GaN is a promising next-generation microLED material platform, as it provides narrow-linewidth, wavelength-stable red emission based on intra-4f-shell transitions of Eu ions. In this research, it was found that growing these on a semipolar crystal plane selectively promotes the formation of highly efficient Eu luminescent centers, resulting in red emission intensity more than 3.6 times higher than that of a conventionally grown material.

US-based Verticle Inc. has developed "defect-free wet chemical etching", a new process that can be used to etch AlGaInP red microLEDs, with an improved performance and results compared to dry etching. In order to adopt its red micro-LED wet etching technology in micro-LED manufacturing process and expedite micro-LED commercialization, Verticle is now offering wet etching foundry service for microLED developers and display and chip makers.

Sidewall defect penetration depth of the 30x30 mm AlGaInP microLEDs (wet vs dry etching, no prost-etch treatment)

The company says that  its unique defect-free wet etching process can enhance red microLED efficiency by preventing defect generation in the red pixel sidewall, hence, minimizing sidewall defect penetration depth. As a result, effective light emitting area is 3 times bigger than dry etched pixel (see above).

Researchers from the University of Michigan, led by Prof. Zetian Mi, have developed a new 3D Nanowire red microLED emitter that achieves a very narrow emission spectrum - an FWHM of 5nm at 617 nm, about one order of magnitude narrower than previously reported values. A narrow emission spectrum helps to realize wide color gamuts.

To achieve this high performance, the researchers realized a nanowire photonic crystal (PhC) structure that reforms the radiation behavior of red-emitting InGaN micro-LEDs.

Researchers from Korea's KAIST, Inha University, QSI and Raontech have jointly developed a high-density high-efficiency red microLED microdisplay, achieving a pixel density of 1700 PPI.

The researchers used Aluminum Indium Phosphide/Gallium Indium Phosphide (AlInP/GaInP) quantum-well microLEDs, and applied a monolithic 3D integration process to stack the microLED array directly on top of the backplane.

Researchers from China's Xiamen University, Singapore's Nanyang Technological University, Xiamen University Malaysia , Birkenau University (Turkey), and Lattice Optoelectronics have developed a new red InGaN LED device that achieved high efficiency - 11.78% EQE, and 1.1% EQE at microLED sizes (10 micron).

To achieve this high efficiency, the researchers have optimized the device V-pit to promote the effectiveness of three-dimensional current pathways and facilitate localized electric field redistribution. The researchers explain that this improvement enhances hole injection while suppressing nonradiative recombination, this work contributes to the microstructure design in InGaN-based red LEDs.

The MicroLED Industry Association published a new white paper that provides a discussion on microLED full color architectures. The white paper is openly available to download here.

One of the key challenges still facing the microLED industry is the development of full color displays. As blue, green and red LEDs are based on different material structures, producing full-color displays is not straightforward. MicroLED display developers are looking at several full color architectures, including a native GaN red microLED, color-tunable LEDs, color conversion using phosphors/QDs, and alternative material platforms (such as 3D Nanowires) and processes.

The MicroLED Association Full Color Architectures white paper addresses the challenges associated with producing full color microLED displays, and details the different architectures and technologies being developed today. You can download the full white paper here!

MicroLED-Connect 2025 is set to be the industry’s premier event for 2025, with a world-class agenda, exhibition and networking opportunities. In this article we will introduce some of our speakers and themes in the event. You can explore the full agenda and event details here.

Mass transfer – lasers, fluids and chip-first processing

The first theme we will discuss is mass transfer. In most MicroLED production platforms, there is at least one transfer process – from epiwafer to final display, and usually at least two such processes are involved: from epiwafer to an interposer substrate (temporary holder)  and then from interposer to final display. Performing this transfer in a cost-efficient and reliable manner is still one of the major challenges the industry is facing.

MicroLED-Connect is the microLED industry's top event series, offering a combination of exciting online webinars and a flagship annual on-site event. Our next meeting is on 23-25 September 2025, at the High Tech Campus, Eindhoven, Netherlands. MicroLED-Connect is co-organised by TechBlick and the MicroLED Industry Association and offers the best way to connect with the global MicroLED and AR/VR display industries and markets.

In this article, we will share a few short videos from past events. First up, we have Continental's Kai Hohmann that discusses how the company looks at the four competing display technologies, and the opportunities for microLED technology in the automotive industry.

The MicroLED Industry Association will host an online meeting on June 16, 2025, with a focus on red microLED emission, one of the key challenges towards mass microLED adoption.

This first-of-its-kind panel meeting will take a deep look into red microLED emission. The several potential paths towards a commercial red microLED will be discussed: native GaN red, color conversion, color-tunable LEDs and 3D GaN Nanowires.

Plessey Semiconductors, together with Meta Platforms, announced that they have developed a native red microLED microdisplay that achieves up to 6 million nits with a chip size of 5 um. Plessey says that this is world's brightest microLED device at this size.

In March 2020, Meta signed a deal with Plessey to dedicate all of Plessey's microLED manufacturing operations to support Meta with its own product development. Facebook pretty much acquired Plessey's microLED operations with this exclusive deal.