Germanium-Tin Single-Photon Avalanche Diodes Detectors for Imaging and Sensing Applications

Single photon avalanche diodes (SPADs) are devices that can precisely time the arrival of single photons of light. SPADs operating in the short-wave infrared (SWIR) have numerous applications including 3D imaging (e.g. for autonomous vehicle LIDAR) and in remote sensing of pollutants such as methane. Current state-of-the-art technology is expensive and is limited to low repetition rates. This project will develop SWIR SPADs which are compatible with fabrication using ubiquitous Si foundries, making them suitable for mass manufacturing at low cost. This can be achieved by extending the absorption of standard Si SPADs with an absorbing material based on GeSn alloys. The student will be designing, fabricating and characterising such GeSn-on-Si SPADs, which have the real potential to be a disruptive technology, enabling long range LIDAR imaging and sensing systems at a fraction of the cost of currently available technology.