Theoretical gain of strained GeSn[sub 0.02]/Ge[sub 1−x−y[sup ʹ]]Si[sub x]Sn[sub y[sup ʹ]] quantum well laser
Date of Issue2010
School of Electrical and Electronic Engineering
2National Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of
Using effective-mass Hamiltonian model of semiconductors quantum well structures, we investigate the electronic structures of the -conduction and L-conduction subbands of GeSn/GeSiSn strained quantum well structure with an arbitrary composition. Our theoretical model suggests that the band structure could be widely modified to be type I, negative-gap or indirect-gap type II quantum well by changing the mole fraction of -Sn and Si in the well and barrier layers, respectively. The optical gain spectrum in the type I quantum well system is calculated, taking into account the electrons leakage from the -valley to L-valley of the conduction band. We found that by increasing the mole fraction of -Sn in the barrier layer and not in the well layer, an increase in the tensile strain effect can significantly enhance the transition probability, and a decrease in Si composition in the barrier layer, which lowers the band edge of -conduction subbands, also comes to a larger optical gain.
DRNTU::Engineering::Electrical and electronic engineering
Journal of applied physics
© 2010 American Institute of Physics. This paper was published in Journal of Applied Physics and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following official DOI: http://dx.doi.org/10.1063/1.3329424. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.