Glasgow University works with local firms on single photon detectors

CST Global, the Glasgow-based III-V opto-electronic, semiconductor foundry, is collaborating with the University of Glasgow and Gas Sensing Solutions on a project to fabricate active matrix, single-photon GaAs devices.

The project will develop light-weight, monolithic, mid-wave infrared (MWIR) imagers, capable of detecting a single photon of IR light.

Dr Laura Meriggi

These are primarily used to image gasses and diagnose their composition.

Dr Laura Meriggi, device development engineer at CST Global and project lead, writes:

“Current, commercially available, MWIR imaging systems require expensive, cryogenic cooling to operate. They are bulky, use high-cost materials and are difficult to produce. However, if produced in a lower cost format, they have the potential to be used to improve human health and safety in a wide range of markets, such as biomedical imaging and environmental monitoring.”

Most likely applications include military, home safety and the oil and gas industries.

A research group at the University of Glasgow, along with commercial partners, QuantIC and Gas Sensing Solutions (GSS), have previously developed an MWIR imager which integrates indium antimonide (InSb) photodiodes (PDs) with gallium arsenide (GaAs) metal semiconductor field effect transistors (MESFETs) to individually address each pixel.

Called IndiPix it was able to detect and image carbon dioxide concentration. It also operates at room temperature and eliminates the need for flip-chip bonding, the costly and low-yield manufacturing process previously used.

“The MWIR imaging project at CST Global will transfer the current monolithic, MWIR imager technology into a compact, commercially viable, 4” wafer format. This will make it a highly cost-effective way of imaging trace gases,” said Meriggi.

The MWIR imaging project is government-funded through Innovate UK and the Engineering and Physical Sciences Research Council (EPSRC).

CST Global is the project leader and will receive £131,600 contribution over 18 months from October 2017, with a total project fund value of £320,271.