Polar Light creates red light from its new pyramidal microLED

06 Jan 2025

625 nm output from non-etching, bottom-up design is based on same source materials as previous green and blue sources.

Now available in red.

Polar Light Technologies, Linköping, Sweden, has achieved an output from its pyramidal microLED design of red light of 625 nm, based on the company’s non-etching bottom-up concept. This means Polar Light Technologies has created red, green, and blue pyramidal microLEDs using the same material compound, which the company describes as “a breakthrough”.

The pyramidal design has the ability to be manufacturable while maintaining excellent microLED performance, laying the foundation for monolithic RGB displays. This achievement marks the culmination of years of rigorous research and development, truly enabling spatial computing and next-generation panel displays.

Blue and green MicroLEDs have been in the market for years, but reaching a red color has been difficult due to fundamental challenges in the material properties. There are several workarounds or alternatives for reaching a red colour, but they all come with some compromises, such as efficiency, manufacturability, or the need to integrate with other material systems.

“Pursuing Polar Lights’ innovative pyramidal LED concept has been about overcoming those challenges without compromises. Today, thanks to our great tech team, we have succeeded in realizing the red-emitting microLEDs based on our innovative pyramidal structure,” said Lisa Rullik, CTO of Polar Light Technologies.

Pyramidal structures

Polar Light Technologies’ microLED is composed of pyramid shapes that are built with a novel bottom-up approach, a technology that comes with certain properties:

The inevitable strain in the lattice-mismatched InGaN/GaN structures is reduced, which is important to be able to manufacture blue, green, and red microLEDs with the same material system, that is, to build monolithic RGB.
Enables the possibility to integrate the frontplane with a backplane.
No etching is needed, which means performance is maintained also for smaller dimensions since no etching damage occurs; and it enables even sub-µm LEDs – “nanoLEDs”
Easier to manufacture and integrate with CMOS and TFT
Narrow emission cone: Lambertian light lobe from the emitter, which is important for microprojectors.

Performance and manufacturability

Polar Light Technologies’ same-compound-based microLED offers high performance and excellent manufacturability. Its very small dimensions and narrow emission cone further enhance the offer. The technology also opens up for nanoLED applications – as soon as the rest of the display technology catches up.

“Our technology addresses microLED challenges in a way that has never been done before,” said Oskar Fajerson, CEO of Polar Light Technologies. “Now we’re moving towards commercialization of this groundbreaking technology, focusing on putting products on the market.”

The company has developed what it calls a “bottom-up approach” for manufacturing pyramidal microLEDs using controlled crystal growth, atomic layer by atomic layer. This eliminates the top-down destructive etching used by some other manufacturers. The result is unmatched pixel size, brightness and energy efficiency. The company has its roots in long and unique research done by Professor Per-Olof Holtz at Linköping University, with support from Vinnova, Sweden’s innovation agency.