Abstract:
QCDs are emerging technology which has shown to encompass wavelengths
from near-infrared to the THz region. The design of QCDs has
proven to be robust and reliable. Especially in the MIR range around 4 to
16 m, well-established semiconductor material systems and processing
procedures are available. MIR range also holds signature absorption peaks
for some greenhouse gases that has significant environmental and chemical
application. Again nitride based material system demonstrate superior
performance in terms of large LO-phonon energy, current capacity, electron
mobility, break-down voltage, and e ciency for power module and
photovoltaic applications. In this thesis, a nitride based material system
simulator is developed using the inherent strain and polarization e ect
of the nitride material. The simulator solves the band structure and energy
values of a nitride based quantum cascade structure. Moreover two
designs of nitride based QCD operating in the mid-infrared region are presented
along with a detail transport and performance analysis. This thesis
also attempts to study important parameters of the nitride based detectors
as function of detector temperature. The strongly varying device resistance
and the drop in responsivity with temperature of the mid-infrared
quantum cascade detectors are numerically calculated based on a model
describing LO-phonon assisted transitions between the di erent involved
states of the quantum cascade.
