Break-through for novel red-emitting pyramidal microLEDs, based on the same
InGaN material system as the green- and blue-emitting
 

With Polar Light Technologies’ novel concept, based on a non-etching bottom-up approach, red light at 625 nm has been achieved. By this remarkable breakthrough, Polar Light Technologies have reached red, green and blue pyramidal microLEDs employing the same material system.

Polar Light Technologies has attained this milestone after more than 15 years research work and development. These novel microLEDs will open the gate towards future spatial computing and next-generation panel displays.

The concept with the pyramidal design employed by Polar Light Technologies, will allow the ability with manufacturable microLEDs, while still maintaining their outstanding performance. Accordingly, the pyramidal microLEDs are ideal candidates for monolithic RGB displays.

Red LED emission without compromises

Due to the nitride material properties, there is an increasing challenge to realize efficient microLEDs as one goes towards longer wavelengths. While blue and green microLEDs have been on the market for years, reaching the red color is facing fundamental challenges due to the internal lattice-mismatch. Red color microLEDs have been demonstrated and reported, but they come with different compromises, such as manufacturability or the need to combine with other material systems.

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

High performance pyramidal LED structures

Polar Light Technologies’ microLED technology is based on a bottom-up approach to form the LEDs of pyramidal design. 

This technology comes with unique benefits:

• A major challenge of the InGaN/GaN material system is the internal strain due to the lattice-mismatch, which can be better handled in PLTs pyramidal structures enabling manufacturing blue, green, and red microLEDs with the same material system, i.e. to build monolithic RGB.
• The pyramidal concept offers unique possibilities for hybridization between the frontplane and the backplane of the microLED.
• A major advantage of PLTs bottom-up concept is that the devastating etching is not needed, which means that the microLED performance can be maintained also as the dimensions of the LED structures are decreasing, since no etching damages will occur
• With PLTs pyramidal concept, it will be easier to integrate with CMOS and TFT
• A narrow output light cone (See Fig x): A Lambertian, or even sub-Lambertian, light lobe from the pyramidal emitter is important for many opto-applications e.g. micro-projectors

These benefits are crucial for the microLED’ performance to solve key challenges for many applications and bring the Polar Light Technologies technology to the market.

Next generation nanoLEDs

Polar Light Technologies’ same-compound-based microLEDs offer high performance combined with excellent manufacturability. Their small dimensions and narrow emission cone further enhance the performance. The possibility to decrease the LED dimensions to the sub-mm regime will enable also the next LED generation – nanoLEDs:

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

About Polar Light Technologies

Polar Light Technologies have developed a novel concept; a bottom-up approach to manufacture pyramidal microLEDs, atomic layer by atomic layer by MOCVD growth. In this way, the top-down destructive etching used for fabrication of micro-LEDs available on the market today can be eliminated. This will result is unmatched pixel size, emission brightness, light cone and energy efficiency. The company has its roots in manifold years unique research performed by Professor Per-Olof Holtz and his research team at Linköping University, with support from Vinnova, Sweden’s innovation agency and the Swedish Foundation for Strategic Research (SSF).

For more information

Oskar Fajerson, CEO of Polar Light Technologies
Telephone: +46 738 19 38 00
oskar.fajerson@polar-light-technologies.com

Lisa Rullik, CTO of Polar Light Technologies.
Telephone: +46 760 21 34 80
lisa.rullik@polar-light-technologies.com

Per-Olof Holtz, founder of Polar Light Technologies and professor at Linköping University
Telephone: +46 708 75 26 28
per-olof.holtz@polar-light-technologies.com