Longwave and bi-color type-II InAs/(In)GaSb superlattice infrared detectors
type: CreativeWork
description: Infrared (IR) photodetectors are useful for a variety of military and civil applications such as target acquisition, medical diagnostics, pollution monitoring, to name just a few. Presently photonic IR detectors are based on interband transitions in low bandgap semiconductors such as mercury cadmium telluride (MCT) or InSb or in intersubband transitions in hetero-engineered structures such as quantum well or quantum dot infrared photodetectors (QWIPs or QDIPs). These detectors operate at low temperatures (77 K-200 K) in order to obtain high signal to noise ratio. The cooling requirement limits the lifetime, increases the weight and the total cost, as well as the power budget, of the whole infrared system. There is a concerted effort to develop photonic detectors operating at higher temperatures. In the past few years, interband transitions in type II InAs/GaSb strain layer superlattices (SL)have emerged as a competing technology among other IR systems. Although MCT and QWIP technologies are relatively more mature than the SL technology, the SL technology has potential to enhance performance in several key areas. One of the main advantages of this system lies in the fact that the effective band gap of the SL can be tailored over a wide range (3 μm < λc < 30 μm) by varying the thickness of two mid bandgap' constituent materials, namely GaSb and InAs. Tunneling currents in SL are reduced due to a larger electron effective mass. Large splitting between heavy-hole and light-hole valence subbands due to strain in the SLs contributes to the suppression of Auger recombination. Moreover, the band structure of the SL can be engineered to enhance carrier lifetimes and reduce noise at higher temperatures. SL based IR detectors have demonstrated high quantum efficiency, high temperature operation, and are suitable for incorporation in focal plane arrays (FPA) by tapping into the mature III-V based growth and fabrication processes. The recently proposed nBn heterostructure design…
abstract: Infrared (IR) photodetectors are useful for a variety of military and civil applications such as target acquisition, medical diagnostics, pollution monitoring, to name just a few. Presently photonic IR detectors are based on interband transitions in low bandgap semiconductors such as mercury cadmium telluride (MCT) or InSb or in intersubband transitions in hetero-engineered structures such as quantum well or quantum dot infrared photodetectors (QWIPs or QDIPs). These detectors operate at low temperatures (77 K-200 K) in order to obtain high signal to noise ratio. The cooling requirement limits the lifetime, increases the weight and the total cost, as well as the power budget, of the whole infrared system. There is a concerted effort to develop photonic detectors operating at higher temperatures. In the past few years, interband transitions in type II InAs/GaSb strain layer superlattices (SL)have emerged as a competing technology among other IR systems. Although MCT and QWIP technologies are relatively more mature than the SL technology, the SL technology has potential to enhance performance in several key areas. One of the main advantages of this system lies in the fact that the effective band gap of the SL can be tailored over a wide range (3 μm < λc < 30 μm) by varying the thickness of two mid bandgap' constituent materials, namely GaSb and InAs. Tunneling currents in SL are reduced due to a larger electron effective mass. Large splitting between heavy-hole and light-hole valence subbands due to strain in the SLs contributes to the suppression of Auger recombination. Moreover, the band structure of the SL can be engineered to enhance carrier lifetimes and reduce noise at higher temperatures. SL based IR detectors have demonstrated high quantum efficiency, high temperature operation, and are suitable for incorporation in focal plane arrays (FPA) by tapping into the mature III-V based growth and fabrication processes. The recently proposed nBn heterostructure design…
author: Khoshakhlagh, Arezou
language: English
date published: 2010-06-28T07:00:00Z
date modified: 2026-07-24T05:26:35Z
provider: University of New Mexico
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of New Mexico

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1928/10882