28 April 2022
Kubos’ cubic GaN 20 times faster than hexagonal GaN LEDs for VLC
Spun out of the University of Cambridge in 2017 – with an exclusive license to develop and commercialize its proprietary cubic-phase gallium nitride (GaN) intellectual property – Kubos Semiconductors Ltd of Cambridge, UK, in collaboration with researchers at the universities of Manchester and Cambridge, has identified the potential for its material to deliver LEDs capable of switching at significantly faster speeds than those produced in the hexagonal crystal phase. Carrier lifetimes in cubic GaN quantum wells have been measured at <0.5ns, which is more than 20 times faster than typical c-plane hexagonal GaN LEDs (≈10ns). Along with other beneficial properties of cubic GaN, these shorter carrier lifetimes offer the potential to develop LEDs across the visible spectrum that can be switched at very high speeds (>1GHz).
“These measurements suggest cubic GaN LEDs could be used in visible light communications (VLC) applications enabling higher-speed connectivity, and we are already seeing some early commercial interest in this area,” says technical director & founder professor David Wallis.
Picture: Kubos’ 25μm (radius) cubic GaN LED, with a quantum well peak in the ‘green gap’.
Kubos is developing its cubic GaN technology to produce improved-efficiency green and amber LEDs and red micro-LEDs for a range of lighting and display applications, and its potential to significantly reduce carbon emissions attributable to solid-state lighting is widely acknowledged. The firm has calculated that this could save as much as 120 million tons of CO2 emissions on an annualized basis (equivalent to the emissions of 32 coal-fired power stations each year). But the possibility of playing an additional role in delivering faster switching speeds in communications applications is groundbreaking.
“The communications sector of the LED market is a progressive and exciting application area,” comments CEO Caroline O’Brien. “The opportunity to significantly improve LiFi and electronic optical backplane communication speeds, for example, opens a whole new segment for Kubos in an already large and growing addressable LED and micro-LED market.”
According to data published by MarketsandMarkets in November 2020, the VLC market is expected to grow to $80.3bn by 2025, with ‘less energy consumption by LEDs’ one of the key factors fueling this growth.