Jul 9 2019
An ultrafast and very sensitive “avalanche photodiode” (APD) that creates less electronic “noise” compared to its silicon rivals has been developed by a research team from the Institute for Compound Semiconductors (ICS) along with collaborators.
(Image credit: Cardiff University)
APDs are extremely sensitive semiconductor devices that manipulate the “photoelectric effect”—when light touches a material—to change light to electricity.
Globally, faster and supersensitive APDs are sought-after for use in high-speed data communications and light detection and ranging (LIDAR) systems for autonomous vehicles.
A paper describing the breakthrough in creating very low excess noise and high sensitivity APDs has been published recently in Nature Photonics.
Cardiff scientists guided by Sêr Cymru Professor Diana Huffaker, Scientific Director of ICS and Sêr Cymru Chair in Advanced Engineering and Materials, partnered with the University of Sheffield and the California NanoSystems Institute, University of California, Los Angeles (UCLA) to create the technology.
Professor Huffaker said, “Our work to develop extremely low excess noise and high sensitivity avalanche photodiodes has the potential to yield a new class of high-performance receivers for applications in networking and sensing. The innovation lies in the advanced materials development using molecular beam epitaxy (MBE) to ‘grow’ the compound semiconductor crystal in an atom-by-atom regime.
She added, “This particular material is rather complex and challenging to synthesize as it combines four different atoms requiring a new MBE methodology. The Sêr Cymru MBE facility, part funded by HEFCW, is designed specifically to realize an entire family of challenging materials targeting future sensing solutions.”
Dr. Shiyu Xie, Sêr Cymru Co-fund Fellow said, “The results we are reporting are significant as they operate in very low-signal environment, at room temperature, and very importantly are compatible with the current InP optoelectronic platform used by most commercial communication vendors.
“These APDs have a wide range of applications. In LIDAR, or 3D laser mapping, they are used to produce high-resolution maps, with applications in geomorphology, seismology and in the control and navigation of some autonomous cars.
Our findings can change the global field of research in APDs. The material we have developed can be a direct substitute in the current existing APDs, yielding a higher data transmission rate or enabling a much longer transmission distance.
Dr. Shiyu Xie, Sêr Cymru Co-fund Fellow, ICS, Cardiff University
The Sêr Cymru Group within ICS is currently getting a proposal ready along with coworkers at Sheffield for funding from UK Research and Innovation to aid further research.
The work of Professor Huffaker’s Sêr Cymru Group plays a vital role in supporting the ongoing success of the wider Compound Semiconductor cluster, CS Connected, which brings together ten industry and academic partners in South Wales to develop 21st Century technologies that create economic prosperity.
Professor Colin Riordan, Vice-Chancellor, Cardiff University
Professor Huffaker added, “Our research produces direct benefits for industry. We are working closely with Airbus and the Compound Semiconductor Applications Catapult to apply this technology to future free space optics communication system.”
The Institute for Compound Semiconductors
(Video credit: Cardiff University)