Open AccessDesign of a Si-based lattice-matched room-temperature GeSn/GeSiSn multi-quantum-well mid-infrared laser diode
Author(s) -
Genban Sun,
Richard A. Soref,
Hung-Hsiang Cheng
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.019957
Subject(s) - materials science , quantum well , auger effect , optoelectronics , infrared , silicon , laser , diode , semiconductor , semiconductor laser theory , carrier lifetime , band gap , quantum efficiency , optics , auger , physics , atomic physics
This paper presents modeling and simulation of a silicon-based group IV semiconductor injection laser diode in which the active region has a multiple quantum well structure formed with Ge(0.9)Sn(0.1) quantum wells separated by Ge(0.75)Si(0.1)Sn(0.15) barriers. These alloy compositions were chosen to satisfy three conditions simultaneously: a direct band gap for Ge(0.9)Sn(0.1), type-I band alignment between Ge(0.9)Sn(0.1) and Ge(0.75)Si(0.1)Sn(0.15,) and a lattice match between wells and barriers. This match ensures that the entire structure can be grown strain free upon a relaxed Ge(0.75)Si(0.1)Sn(0.15) buffer on a silicon substrate - a CMOS compatible process. Detailed analysis is performed for the type I band offsets, carrier lifetime, optical confinement, and modal gain. The carrier lifetime is found to be dominated by the spontaneous radiative process rather than the Auger process. The modal gain has a rather sensitive dependence on the number of quantum wells in the active region. The proposed laser is predicted to operate at 2.3 μm in the mid infrared at room temperature.