4 January 2022
Sheffield-led project developing micro laser diode technology for micro-display and VLC devices
In collaboration with Harvard University and Massachusetts Institute of Technology (MIT) in the USA and the universities Strathclyde and Bath in the UK, a newly funded £1.9m project led by professor Tao Wang of the University of Sheffield’s Department of Electronic and Electrical Engineering in the UK aims to develop novel epitaxy technology to integrate micro laser diodes (micro-LDs) and transistors on a single chip for use in micro-display and visible light communication (VLC) devices.
Micro-displays are used in smartphones, smartwatches, augmented reality (AR) and virtual reality (VR) devices. VLC technology has the potential to offer much greater bandwidth and efficiency than WiFi or 5G and can be used where radio frequency emissions are controlled or do not work, such as in aircraft, hospitals, underwater and hazardous environments.
A key component of both these technologies are III-nitride visible light-emitting diodes (LEDs), but using laser diodes (LDs) instead has the potential to achieve devices with even higher resolution, speed and efficiency.
Funded by the UK’s Engineering and Physical Sciences Research Council (EPSRC), the £1.9m Sheffield-led project is developing a new way of integrating microscale semiconductor light sources and transistors on a single chip.
“The significantly increasing demands on micro-displays are pushing the requirements for ultra-high resolution and ultra-high efficiency,” notes Tao Wang, Professor in Advanced Opto-Electronics at the University of Sheffield. “Several fundamental challenges with fabrication and electrical driving methods cannot be met by existing technologies, therefore a disruptive technology needs to be developed,” he adds. “Unlike any existing photonics and electronics fabrication approaches, our research will explore a completely different approach to monolithically integrate microscale laser diodes (μLDs) and high-electron-mobility transistors (HEMTs) on a single chip, where each μLD is electrically driven by individual HEMTs.”
The global micro-display market is predicted to reach $4.2bn by 2025 and the visible light communication market is expected to exceed $8bn by 2030. The Sheffield-led project is already being supported by global tech companies such as Microsoft, Sony and Plessey.