Near Infra-red Single Photon Detection Using Ge-on-Si Heterostructures

Supervisor: Prof David Leadley

Silicon photonics is a rapidly devloping field that promises to combine the mass market advantages of silicon processing technology with the optical functionality normally provided by III-V seminconductors. Eventually this should lead to full integration of photonic and electronic devices on the same chip, with associated savings in complexity, size, cost and power consumption of device.

This project, funded by an EPSRC grant, will utilise the expertise of the University of Warwick in epitaxial growth of Si, Ge, and SiGe layers from within the NanoSilicon group, combined with the photonic expertise of the Heriott Watt group, design work from Leeds and processing via Surrey Universities.

The PhD student on this project would be involved in the growth and characterisation of such layers, would receive training in a wide variety of techniques of relevance to semiconductor research and gain an appreciation of the field of silicon photonics.

Due to the departure of the student previously engaged on the project on health grounds, this PhD studentship is available for an immediate start. EPSRC funding rules mean that only a UK or EU student can be supportted.

To discuss this project further contact:
d.r.leadley@warwick.ac.uk or EHCParker@warwick.ac.uk

Further Information from EPSRC grant outline

Semiconductor-based photon-counting detectors have risen to prominence in the last decade as new
application areas, such as quantum information processing, have emerged. In the near-infrared, there
are substantial issues with single-photon avalanche diode (SPAD) detectors, as their performance
deteriorates at higher wavelengths due to the increased noise levels associated with the narrow bandgap
semiconductors normally used.

This project aims to establish a new class of germanium/silicon SPADs
that will operate efficiently in the near-infrared, particularly at the strategically important
telecommunications wavebands, and combine the advantages of low-noise Si single-photon avalanche
multiplication with the infra-red sensing capability of Ge. This new class of detectors will take advantage
of recent advances in epitaxial Ge/Si growth and will be developed in conjunction with the UK Silicon
Photonics consortium (UKSP), which has world leading expertise in silicon photonics research and is
pursuing a comprehensive research programme of active and passive device development with access
to state-of-art growth, processing and characterisation facilities.

The project leverages the combined
expertise and facilities of UKSP to do significant new work, namely the development of a new device
concept and comprehensive testing in application areas outside UKSP’s communications focus, thus
delivering a cost-effective SPAD research programme and adding value to the consortium. The
detectors will be validated on existing state-of-art testbeds for quantum key distribution and time-of-flight
ranging/depth imaging.