Room temperature negative differential resistance in terahertz quantum cascade laser structures

Asaf Albo; Qing Hu; John L. Reno

doi:10.1063/1.4961617

Room temperature negative differential resistance in terahertz quantum cascade laser structures

Asaf Albo, Qing Hu, John L. Reno

Research output: Contribution to journal › Article › peer-review

48 Scopus citations

Abstract

The mechanisms that limit the temperature performance of GaAs/Al_0.15GaAs-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.

Original language	English
Article number	081102
Journal	Applied Physics Letters
Volume	109
Issue number	8
DOIs	https://doi.org/10.1063/1.4961617
State	Published - 22 Aug 2016
Externally published	Yes

Bibliographical note

Publisher Copyright:
© 2016 Author(s).

Funding

This work was supported by NSF and Israel MoD, and also performed at the Center for Integrated Nanotechnologies, a U.S. Department of Energy, Office of Basic Energy Sciences user facility. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

Funders	Funder number
Israel MOD
Office of Basic Energy Sciences
National Science Foundation
U.S. Department of Energy
Lockheed Martin Corporation
National Nuclear Security Administration	DE-AC04-94AL85000

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Cite this

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Room temperature negative differential resistance in terahertz quantum cascade laser structures

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