Bulk unrelaxed InAsSb alloys with Sb compositions up to 44 % and layer thicknesses up to 3 µm were grown by molecular beam epitaxy. The alloys showed photoluminescence (PL) energies as low as 0.12 eV at T = 13 K. The electroluminescence and quantum efficiency data demonstrated with unoptimized barrier heterostructures at T= 80 and 150 K suggested large absorption and carrier lifetimes sufficient for the development of long wave infrared detectors and emitters with high quantum efficiency. The minority hole transport was found to be adequate for development of the detectors and emitters with large active layer thickness.
The optical properties of bulk unrelaxed InAsSb layers having a low temperature photoluminescence (PL) peak up to 10
μm are presented. The materials were grown on GaSb substrates by molecular beam epitaxy. The lattice mismatch
between the epilayers and GaSb substrates was accommodated with linearly graded GaAlInSb buffers. An 11-meV width
of PL at full-width half-maximum was measured for InAsSb with Sb compositions of 20 and 44% . The best fit for the
dependence of the energy gap on Sb composition was obtained with a 0.9-eV bowing parameter. Temperature
dependences of the energy gap for InAsSb alloys with 20 % and 44% Sb were determined from PL spectra in the
temperature range from 12 to 300 K. A T=77 K minority carrier lifetime up to 350 ns in undoped InAsSb layers with
20% Sb was determined from PL kinetics.
GaInSb and AlGaInSb compositionally graded buffer layers grown on GaSb by MBE were used to develop
unrelaxed InAs1-XSbXepilayers with lattice constants up to 2.1 % larger than that of GaSb. The InAsSb buffer
layer was used to grow InAs0.12Sb0.88 layer on InSb. The structural and optical characterization of 1-μm thick
InAs1-xSbx layers was performed together with measurements of the carrier lifetime.
Minority carrier lifetime, photoluminescence (PL), and interband absorption in midinfrared range of spectra were
measured in InAs/GaSb strained-layer superlattices (SLS) grown by molecular beam epitaxy (MBE) on GaSb substrates.
The carrier lifetime was determined by time-resolved PL (TRPL) and from analysis of PL response to sine-wavemodulated
excitation. Studies of the PL kinetics in the frequency domain allowed for direct lifetime measurements in
SLS structures with an excess carrier concentration level of 3.5×1015 cm-3. The minority carrier lifetime at T = 77 K was
obtained from the dependence of the carrier lifetime on excitation power. SLS structures with similar absorption
wavelengths but with different InAs and GaSb layer thicknesses and with different amounts of strain were investigated
and compared with mercury cadmium telluride (MCT) samples. No apparent trend was seen in structures with different
number of interfaces per unit length. All SLS lifetime values measured so far are more than an order of magnitude lower
than those of MCT.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.