Manufacturing scalable semiconductor quantum light sources

Semiconductors have already revolutionised the world around us through the inventions of the transistor, diode lasers, integrated circuits and sensors. A new wave of semiconductor quantum technologies are finding commercial applications in ultra-secure communications, enhanced imaging, sensing, and possibly even computing and simulations. In all these cases the "quantum advantage" is theoretically proven and experimentally demonstrated, but there is a strong need for a scalable, practical and efficient source of quantum light.

Naturally occurring point-like light sources called "colour centres" act as quantum light sources in wide bandgap semiconductors such as diamond, Silicon Carbide, Boron Nitride and Gallium Nitride (GaN) at room temperature. Commercially, GaN now dominates the market for solid state lighting, because it is an efficient and manufacturable material, leading to costs of less than one dollar per LED. However, Gallium-Nitride is also a promising material for quantum light sources as the colour centres within it emit from the ultra-violet to the near infra-red. This wide range means the emission overlaps with minima in the absorption curves of optical fibres (1310 and 1550 nm), transitions in the best atomic quantum memories (near 800nm) and low loss free-space communications in the blue. Furthermore, by engineering heterostructures within the semiconductor it is possible to electrically drive the emitter, rapidly switch the device and design efficiency-enhancing structures.

This fellowship will apply manufacturing techniques widespread in the compound semiconductor manufacturing field, such as large area epitaxy and wafer scale processing, to deliver a bright and room temperature quantum light-emitting diode based on GaN. I will use laser lithography, standardised packaging and quality control to ensure the end device is produced in a manner that enables scale up to mass-production, with the full supply chain within the UK. Collaboration with the...