Room temperature negative differential resistance in terahertz quantum cascade laser structures
Name
Room temperature negative differential resistance in terahertz quantum cascade laser.pdf
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1.56 MB
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Adobe PDF
Checksum (MD5)
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Author(s)
Albo, Asaf
Hu, Qing
Reno, John L.
Date Issued
August 2016
Journal
Applied Physics Letters
Publisher
American Institute of Physics (AIP)
Citation
Albo, Asaf, et al. “Room Temperature Negative Differential Resistance in Terahertz Quantum Cascade Laser Structures.” Applied Physics Letters 109, 8 (August 2016): 081102 © 2016 American Institute of Physics (AIP)
Version
Final published version
Abstract
The mechanisms that limit the temperature performance of GaAs/Al[subscript 0.15]GaAs-based terahertz quantum cascade lasers (THz-QCLs) have been identified as thermally activated LO-phonon scattering and leakage of charge carriers into the continuum. Consequently, the combination of highly diagonal optical transition and higher barriers should significantly reduce the adverse effects of both mechanisms and lead to improved temperature performance. Here, we study the temperature performance of highly diagonal THz-QCLs with high barriers. Our analysis uncovers an additional leakage channel which is the thermal excitation of carriers into bounded higher energy levels, rather than the escape into the continuum. Based on this understanding, we have designed a structure with an increased intersubband spacing between the upper lasing level and excited states in a highly diagonal THz-QCL, which exhibits negative differential resistance even at room temperature. This result is a strong evidence for the effective suppression of the aforementioned leakage channel.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology. Research Laboratory of Electronics
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DOI of Published Version
https://doi.org/10.1063/1.4961617
