Abstract
[Truncated] Infrared detector technology is dominated by photon detectors due to their superior signal to-noise performance and their fast photoresponse, and HgCdTe is regarded as the most important semiconductor alloy material for the fabrication of very high performance infrared photon detectors. Although HgCdTe offers high infrared detector performance, HgCdTe-based technology is challenged by high production costs, low yields, relatively high defect densities, and a very strong dependence of detector cutoffwavelength on alloy composition. Seeking to circumvent these technological challenges, new narrow bandgap semiconductor materials have attracted great research interest { as material alternatives to HgCdTe, for third generation infrared detectors. In particular, InAs/GaSb type-II superlattices offer unique material properties that promise infrared photodetectors with performance levels comparable or superior to those of detectors based on HgCdTe, with the additional potential benefits of the higher yields and lower production costs associated with the well-established group III-V compound semiconductor material technologies.
To a great extent, the performance of infrared photon detectors is determined by material quality, as well as by the fundamental electronic and optoelectronic properties of the semiconductor material. Since electronic transport properties are directly affected by material quality, the study of electronic transport processes and carrier scattering mechanisms yields insights into fundamental limiting mechanisms, and provide crucial information for the optimisation of growth processes, thus enabling the realisation of high performance infrared detectors. Ideally, such electronic transport studies need to be performed on structures fabricated on realistic detector structures at temperatures of relevance to photodetector performance. However, third generation infrared detectors employ multiple layer semiconductor structures which cannot be accurately characterised employing conventional magnetotransport characterisation and analysis methods. It is thus that the development of third generation infrared detectors can be significantly advanced by the development of electronic transport characterization and analysis methods that enable accurate quantification of individual carrier transport parameters in complex multi-layer and multi-carrier structures.
To a great extent, the performance of infrared photon detectors is determined by material quality, as well as by the fundamental electronic and optoelectronic properties of the semiconductor material. Since electronic transport properties are directly affected by material quality, the study of electronic transport processes and carrier scattering mechanisms yields insights into fundamental limiting mechanisms, and provide crucial information for the optimisation of growth processes, thus enabling the realisation of high performance infrared detectors. Ideally, such electronic transport studies need to be performed on structures fabricated on realistic detector structures at temperatures of relevance to photodetector performance. However, third generation infrared detectors employ multiple layer semiconductor structures which cannot be accurately characterised employing conventional magnetotransport characterisation and analysis methods. It is thus that the development of third generation infrared detectors can be significantly advanced by the development of electronic transport characterization and analysis methods that enable accurate quantification of individual carrier transport parameters in complex multi-layer and multi-carrier structures.
Original language | English |
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Qualification | Doctor of Philosophy |
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Award date | 7 Jun 2016 |
Publication status | Unpublished - 2015 |