Harrison, P., Indjin, D., Jovanovic, V.D., Mircetic, A., Ikonic, Z., Kelsall, R.W., McTavish, J., Savic, I., Vukmirovic, N. and Milanovic, V. (2005) A physical model of quantum cascade lasers: Application to GaAs, GaN and SiGe devices. Physica Status Solidi (A): Applied Research, 202 (6). pp. 980-986. ISSN 1521-396X
Available under licence : See the attached licence file.
The philosophy behind this work has been to build a predictive bottom up physical model of quantum cascade lasers (QCLs) for use as a design tool, to interpret experimental results and hence improve understanding of the physical processes occurring inside working devices and as a simulator for developing new material systems. The standard model uses the envelope function and effective mass approximations to solve two complete periods of the QCL under an applied bias. Other models, such as k·p and empirical pseudopotential, have been employed in p-type systems where the more complex band structure requires it. The resulting wave functions are then used to evaluate all relevant carrier-phonon, carrier-carrier and alloy scattering rates from each quantised state to all others within the same and the neighbouring period. This information is then used to construct a rate equation for the equilibrium carrier density in each subband and this set of coupled rate equations are solved self-consistently to obtain the carrier density in each eigenstate. The latter is a fundamental description of the device and can be used to calculate the current density and gain as a function of the applied bias and temperature, which in turn yields the threshold current and expected temperature dependence of the device characteristics. A recent extension which includes a further iteration of an energy balance equation also yields the average electron (or hole) temperature over the subbands. This paper will review the method and describe its application to mid-infrared and terahertz, GaAs, GaN, SiGe cascade laser designs.
|Copyright, Publisher and Additional Information:||© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. This is an author produced version of a paper which subsequently published in Physica Status Solidi (A).|
|Institution:||The University of Leeds|
|Academic Units:||The University of Leeds > Faculty of Engineering (Leeds) > School of Electronic & Electrical Engineering (Leeds) > Institute of Microwaves and Photonics (Leeds)|
|Depositing User:||Repository Officer|
|Date Deposited:||22 Mar 2006|
|Last Modified:||05 Jun 2014 05:29|