@inproceedings{4acef78fdac64c05bc1e9699d709ecaf,
title = "Suppression of carrier leakage in 4.8 μm - Emitting quantum cascade lasers",
abstract = "In this work we show that by using both deep quantum wells and tall barriers in the active regions of quantum cascade (QC)-laser structures and by tapering the conduction-band edge of both injector an extractor regions one can significantly reduce the leakage of the injected carriers. Threshold-current, Jth and differential-quantum efficiency, ηd characteristic temperatures, T0 and T1, values as high as 278 K and 285 K are obtained to 90°C heatsink temperature, which means that Jth and ηd vary ∼ 2.5 slower over the 20-90°C temperature range than in conventional QC devices. Modified equations for J th and ηd are derived. In particular, the equation for ηd includes, for the first time, its dependence on heatsink temperature. A model for the thermal excitation of injected carriers from the upper lasing level to upper active-region energy states from where they relax to lower active-region energy states or get scattered to the upper Γ miniband is employed to estimate carrier leakage. Good agreement with experiment is obtained for both conventional QC lasers and deep-well (DW)-QC lasers.",
keywords = "Carrier leakage, Mid-infrared, Quantum-cascade lasers, Slope-efficiency characteristic temperature, Strain-compensated, Threshold-current characteristic temperature",
author = "D. Botez and Shin, {J. C.} and Mawst, {L. J.} and I. Vurgaftman and Meyer, {J. R.} and S. Kumar",
year = "2010",
doi = "10.1117/12.842593",
language = "English",
isbn = "9780819480125",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
booktitle = "Novel In-Plane Semiconductor Lasers IX",
note = "Novel In-Plane Semiconductor Lasers IX ; Conference date: 25-01-2010 Through 28-01-2010",
}