Plessey Semiconductors announced that it has worked with Nanoco Technologies, the UK-based cadmium-free quantum dot (CFQD) provider to shrink the pixel size of monolithic Micro LED displays.

By combining Nanoco’s CFQD semiconductor nanoparticle technology and its existing monolithic process, Plessey will integrate the quantum dots into selected regions of blue LED wafers to add red and green light. The process could shrink the practical pixel size by 87 percent, from today’s 30µm to 4µm. The advance enables the production of smaller Micro LED displays with higher resolution for applications like wearables and mobile devices.

Phosphors are common materials to combine with LEDs for full-color displays. However, the size of smallest phosphor particle is about 30µm, which is similar to the size of Micro LED chips, making it difficult for color conversion. Plessey noted that Nanoco’s CFQD quantum dot technology overcomes this limitation while facilitating efficient, compact device packaging.

“Quantum dots offer the best solution for today’s emerging display requirements. The nano-sized emitters with narrow band emission make them a suitable solution for Plessey’s Micro LED display roadmap, which will see pixels being driven down to 4µm in size by 2019,” said Mike Lee, President of Corporate and Business Development at Plessey.

Dr. Brian Gally, Nanoco’s Head of Product, added, “The combination of Plessey’s blue Micro LEDs with Nanoco’s red and green cadmium free quantum dots gives display customers the performance they require to rapidly commercialize products.”