Download Antimonide-based type II heterostructures

MSE SEMINAR
February 5, 2010
113 McBryde Hall
3:30 – 4:30
Refreshments at 3:00
Dr. Konstantin Moiseev
Ioffe Institute of Physics and Technology
Saint Petersburg, Russia
“Antimonide-based Type II Heterostructures in
Narrow-gap III-V Systems”
ABSTRACT
A study of structural, optical and transport phenomena in type II arsenide-antimonide heterojunctions with
a broken-gap alignment will be presented. In such heterostructures, electrons and holes are spatially
separated and localised in self-consistent quantum wells formed on both sides of the heterointerface. This
leads to unusual tunnelling-assisted radiative recombination transitions and novel transport properties.
The broken-gap alignment presents a considerable advantage in tuning the effective band gap from middle
to far infrared spectrum range.
The solid solutions in the Ga-In-As-Sb system can form type II heterojunctions with both staggered
and broken-gap alignment with GaSb and InAs binary compounds. An intriguing behavior of a quantum
magnetotransport in a 2D-electron system in the presence of localised holes in high magnetic fields and an
observation of integer Quantum Hall effect plateaus at the single type II broken-gap GaInAsSb/InAs
heterointerface are considered.
Type II heterostructures with InSb quantum dots (QDs) inserted into the InAs-based p-n junction can
be obtained by LPE-MOVPE combine method. High density (>2×1010 cm-2) uniform QDs with the height of
3 nm and diameter of 14 nm were found to be self-assembled and dislocation-free without any extended
defects. I-V characteristics of mesa-diode heterostructures with InSb QDs inserted into InAs p-n junction
were studied. Intense positive and negative electroluminescence for both n-InAs/p-InAs and n-InAs/InSbQDs/p-InAs heterostructures was found in the spectral range 3-4
T = 300 K. An
evolution of spectra with applied external bias (both forward and reverse) will be discussed and the energy
band diagram will be proposed.
Novel mid-infrared tunnelling-injection laser based on type II broken-gap heterojunction in the
active region is proposed and some applications of type II broken-gap heterostructures for improved
performance of MIR light-emitting diodes, lasers, photodiodes, and Hall sensors will be briefly reviewed.
BIOSKETCH
Konstantin D. Moiseev received his M.S. Degree in Semiconductor Physics in 1988 from the Radio-Physics
Department of the State Polytechnic Institute, Saint Petersburg, Russia. He received his Ph.D. in Physics in
1995 and his Doctor of Sciences Degree in 2005, both from the Ioffe Institute of Physics and Technology of
the Russian Academy of Sciences. Dr. Moiseev is presently a leading researcher at the Laboratory of
Infrared Optoelectronics and the head of the group of physics and technology of narrow-gap
semiconductor nanoheterostructures at the Ioffe Institute. His main fields of scientific interests are
epitaxial growth and research of GaSb-InAs semiconductor heterostructures for mid-infrared
optoelectronics (diode lasers, light-emitting diodes, photodetectors). His research includes quantum
magnetotransport phenomena in low-dimensional systems, electro- and photoluminescence
measurements and diode-structure engineering.