Modeling of semiconductor devices based on quantum wells: quantum cascade laser as an example
Author
Abbasian, Hamed
Advisor
Gülseren, Oğuz
Date
2018-02Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Show full item recordAbstract
It has been two decades since the quantum-cascade lasers (QCLs) have emerged
in 1994 for the first time. As time goes on, QCLs reach to higher points scientifically and economically and the usage of QCLs devices continually grows
in optoelectronic device market because of their potential applications in various
areas in mid- and far-infrared regions. Moreover, their performance is still
improving. QCLs lase based on electron transition between intersubbands and
tunneling through potential barriers where electron transition causes photon emission.
This takes place in conduction band; that is why QCLs are considered as
unipolar semiconductor lasers. The frequencies of emitted photons depend on the
location of the allowed energy levels which can be controlled by carefully choosing
consecutive wells and barriers with suitable widths. In the present thesis,
the transfer matrix method is employed to obtain transmission coe cient and
wave functions of electron inside an arbitrary potential profile which is crucial for
characterizing semiconductor devices based on quantum well. The obtained wave
functions are used to get quantities necessary for characterizing QCL resulted
from the potential profile.