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Mid-IR type-II InAs/GaSb nanoscale superlattice sensors


Please use this identifier to cite or link to this item: http://hdl.handle.net/1928/3282

Mid-IR type-II InAs/GaSb nanoscale superlattice sensors

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dc.contributor.author Plis, Elena A.
dc.date.accessioned 2007-09-09T06:15:44Z
dc.date.available 2007-09-09T06:15:44Z
dc.date.issued 2007-09-09T06:15:44Z
dc.date.submitted May 2007
dc.identifier.uri http://hdl.handle.net/1928/3282
dc.description.abstract The detection of mid-wavelength infrared radiation (MWIR) is very important for many military, industrial and biomedical applications. Present-day commercially available uncooled IR sensors operating in MWIR region (2-5µm) use microbolometric detectors which are inherently slow. Available photon detectors (mercury cadmium telluride (MCT), bulk InSb and quantum well infrared detectors (QWIPs))overcome this limitation. However, there are some fundamental issues decreasing their performance and ability for high temperature operation, including fast Auger recombination rates and high thermal generation rate. These detectors operate at low temperatures (77K-200K) in order to obtain high signal to noise ratio. The requirement of cooling limits the lifetime, increases the weight and the total cost, as well as the power budget, of the whole infrared system. In recent years, InAs/GaSb superlattice based detectors have appeared as an interesting alternative to the present-day IR detector systems. These heterostructures have a type-II band alignment such that the conduction band of InAs layer is lower than the valence band of GaSb layer. The effective bandgap of these structures can be adjusted from 0.4 eV to values below 0.1 eV by varying the thickness of constituent layers leading to an enormous range of detector cutoff wavelengths (3-30µm). The InAs/GaSb SLs have a higher degree of uniformity than the MCT alloys, making them attractive for large area focal plane arrays. They provide a smaller leakage current due to larger effective electron mass, which suppresses tunneling. This material system is also characterized by high operating temperatures and long Auger recombination rates. This suggests the potential for using the SLs technology for realizing high operating temperature devices. This work is focused on the development of mid-IR InAs/GaSb SLs sensors with high-operating temperature. Contributions of this thesis include 1) development of growth and processing procedure for the n-on-p and p-on-n design of SL detectors leading to improved detector performance, 2) careful evaluation of characteristics of SL detectors, 3) methods of reduction of surface component of dark current passivation techniques). en_US
dc.format.extent 3031753 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US en_US
dc.subject Infrared Sensors en_US
dc.subject Superlattice en_US
dc.subject InAs/GaSb en_US
dc.subject Focal Plane Array en_US
dc.subject.lcsh Infrared detectors--Materials
dc.subject.lcsh Superlattices as materials
dc.title Mid-IR type-II InAs/GaSb nanoscale superlattice sensors en_US
dc.type Dissertation en_US
dc.description.degree Doctor of Engineering en
dc.description.level Doctoral en
dc.description.department University of New Mexico. Dept. of Electrical and Computer Engineering en
dc.description.advisor Krishna, Sanjay
dc.description.committee-member Aceves, Alejandro
dc.description.committee-member Stintz, Andreas
dc.description.committee-member Huffaker, Diana

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