Biasselectable nBn dualband long/very longwavelength infrared photodetectors based on InAs/InAs1xSbx/AlAs1xSbx typeII superlattices
Journal Article - Open Access
Northwestern University Evanston United States
Pagination or Media Count:
TypeII superlattices T2SLs are a class of artificial semiconductors that have demonstrated themselves as a viable candidate to compete with the stateoftheart mercurycadmiumtelluride material system in the field of infrared detection and imaging. Within typeII superlattices, InAsInAs1xSbx T2SLs have been shown to have a significantly longer minority carrier lifetime. However, demonstration of highperformance dualband photodetectors based on InAsInAs1xSbx T2SLs in the long and very long wavelength infrared LWIR and VLWIR regimes remains challenging. We report the demonstration of highperformance biasselectable dualband longwavelength infrared photodetectors based on new InAsInAs1xSbxAlAs1xSbx typeII superlattice design. Our design uses two different bandgap absorption regions separated by an electron barrier that blocks the transport of majority carriers to reduce the dark current density of the device. As the applied bias is varied, the device exhibits welldefined cutoff wavelengths of either approx. 8.7 or approx. 12.5micrometers at 77K. This biasselectable dualband photodetector is compact, with no moving parts, and will open new opportunities for multispectral LWIR and VLWIR imaging and detection.
- Electrical and Electronic Equipment