Full-colour microLED pixels shrunk by 87% using quantum dots

Plessey Semiconductors and Nanoco Technologies has partnered to shrink the pixel size of monolithic microLED displays using Nanoco’s cadmium-free quantum dot (CFQD quantum dots) semiconductor nanoparticle technology. Using its current monolithic process, Plessey will incorporate the CFQD quantum dots into chosen regions of blue LED wafers to add red and green light. This shrinks the smallest practical pixel size from today’s 30µm to just 4µm, a decrease of 87%. The process will allow the creation of smaller, higher-resolution, microLED displays in applications such as watches, AR/VR devices, and mobile devices while enhancing both colour rendition and energy efficiency. For pixels of 30µm or greater, colour conversion is currently done by adding phosphors to the blue die. However, since the smallest phosphor particle is around 30µm, the efficiency of colour conversion degenerates as the pixel size shrinks. The quantum dot technology defeats this limitation while facilitating compact, efficient 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 microLED 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 commented: “We are thrilled to be working in close collaboration with Plessey, who lead the global field in the development and production of mircroLED arrays. The combination of Plessey’s blue microLEDs with Nanoco’s red and green cadmium free quantum dots gives display customers the performance they require to rapidly commercialise products.”