Setting LWIR state of the Art using T2SL detectors (LIRA)

Lead Research Organisation: Cardiff University
Department Name: School of Physics and Astronomy

Abstract

The infrared regime has become the next frontier in the future of photonics providing crucial information from our environment which we cannot see with our eyes. There is a need for high-performance detectors, i.e. quantum (photonic) infrared detectors with high detectivity (low dark current and high quantum efficiency), for specific military (soldier vision enhancement, missile tracking/seeker) and space (earth observation) applications.

This PhD research project will focus on Type-II SuperLattice (T2SL) material as the device absorption region since it is considered a promising candidate for the next generation of high-performance infrared imaging systems (high operating temperature, multispectral, large focal plane array). Thanks to its unique properties, this material has theoretical potential to outperform, in the long-wavelength infrared (LWIR) spectral domain, state-of-the-art infrared technologies such as Mercury Cadmium Telluride (MCT) and GaAs/GaAlAs Quantum Well Infrared Photodetector. However, its theoretical performance has not yet been reached; this is directly related to the low minority carrier lifetime due to defects in the T2SL material. Our approach to achieve high-performance detectors is to explore the relationship between T2SL design, epitaxy and overall device design to achieve state-of-art performance in the 8-12micrometre spectral regime.

This project has great opportunity for scientific and industrial impact. We will explore the most important challenges in this wavelength regime and develop those promising approaches towards room-temperature operation of LWIR detectors and focal-plane arrays. We will identify defect types in the MBE-grown epilayers then mitigate their influence on device performance. We will explore sophisticated device design and architecture. Moreover, we will compare native GaSb substrates to industrially relevant GaAs and identify the optimum combination of substrate (material, type, orientation) and device design for industrial application, scale-up and potential focal plane array development.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S024441/1 01/07/2019 31/12/2027
2265813 Studentship EP/S024441/1 01/10/2019 11/11/2023 Paradeisa O'Dowd Phanis