Tunable energy gaps and mid-infrared optical properties in InAs/GaSb type-II superlattices

2017 ◽  
Vol 31 (13) ◽  
pp. 1750098 ◽  
Author(s):  
H. M. Dong ◽  
Q. Jin ◽  
X. F. Wang
Keyword(s):  
Layer Thickness ◽  
Type Ii ◽  
Gasb Layer ◽  
Energy Gaps ◽  
Short Period ◽  
Type Ii Superlattices ◽  
Text Model ◽  
Theoretical Results ◽  
Infrared Optical Properties ◽  
Good Agreement

We investigate on the infrared (IR) optoelectronic properties in short-period InAs/GaSb type-II superlattices (SLs) by a modified eight-band [Formula: see text] model. The electronic mini-band structures for such SLs are evaluated by the modified eight-band [Formula: see text] model, incorporating the microscopic interface effect. We find that with varying the values around 20/25 Å for the InAs/GaSb layer widths, the tunable mid-IR bandgaps can be achieved effectively. The SL bandgap from 275 to 346 meV can be achieved by decreasing the InAs layer thickness from 23 to 17 Å at a fixed GaSb layer thickness of 24 Å, or from 254 to 313 meV by increasing the GaSb layer thickness from 18 to 27 Å at a fixed InAs layer thickness of 21 Å. Correspondingly the optical absorptions in such systems can be tuned evidently. Our theoretical results are in good agreement with experimental data over a series of SL samples. This study confirms further that short-period InAs/GaSb type-II SLs are of great importance for IR applications.

Spectral blueshift and improved luminescent properties with increasing GaSb layer thickness in InAs–GaSb type-II superlattices

2001 ◽  
Vol 89 (4) ◽  
pp. 2185-2188 ◽  
Author(s):  
Andrew P. Ongstad ◽  
Ron Kaspi ◽  
Charles E. Moeller ◽  
Michael L. Tilton ◽  
Donald M. Gianardi ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Luminescent Properties ◽  
Type Ii ◽  
Gasb Layer ◽  
Type Ii Superlattices

The structure of the Cincinnati arch as determined by short period Rayleigh waves

1969 ◽  
Vol 59 (1) ◽  
pp. 399-407
Author(s):  
Robert B. Herrmann
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Layer Thickness ◽  
Rayleigh Waves ◽  
Layer Model ◽  
Depth Data ◽  
Short Period ◽  
Best Fitting ◽  
Good Agreement

Abstract The propagation of Rayleigh waves with periods of 0.4 to 2.0 seconds across the Cincinnati arch is investigated. The region of investigation includes southern Indiana and Ohio and northern Kentucky. The experimental data for all paths are fitted by a three-layer model of varying layer thickness but of fixed velocity in each layer. The resulting inferred structural picture is in good agreement with the known basement trends of the region. The velocities of the best fitting theoretical model agree well with velocity-depth data from a well in southern Indiana.

Short-period InAs／GaSb type-II Superlattices for Mid-infrared Detection

2017 ◽  
Vol 23 (4) ◽  
pp. 387-392
Author(s):  
袁方园 YUAN Fang-yuan ◽  
金芹 JIN Qin
Keyword(s):  
Infrared Detection ◽  
Type Ii ◽  
Mid Infrared ◽  
Short Period ◽  
Type Ii Superlattices

Interfaces as design tools for short-period InAs/GaSb type-II superlattices for mid-infrared detectors

2005 ◽  
Author(s):  
F. Szmulowicz ◽  
H. J. Haugan ◽  
G. J. Brown ◽  
K. Mahalingam ◽  
B. Ullrich ◽  
...  
Keyword(s):  
Infrared Detectors ◽  
Design Tools ◽  
Type Ii ◽  
Mid Infrared ◽  
Short Period ◽  
Type Ii Superlattices

Mid-infrared absorption by short-period InAs/GaSb type II superlattices

2009 ◽  
Vol 40 (4-5) ◽  
pp. 815-817
Author(s):  
L.L. Li ◽  
W. Xu ◽  
Z. Zeng ◽  
A.R. Wright ◽  
C. Zhang ◽  
...  
Keyword(s):  
Infrared Absorption ◽  
Type Ii ◽  
Mid Infrared ◽  
Short Period ◽  
Type Ii Superlattices

Interfaces as design tools for short-period InAs/GaSb type-II superlattices for mid-infrared detectors

2006 ◽  
Vol 14 (1) ◽  
Author(s):  
F. Szmulowicz ◽  
H. Haugan ◽  
G. Brown ◽  
K. Mahalingam ◽  
B. Ullrich ◽  
...  
Keyword(s):  
Detection Threshold ◽  
Oscillator Strengths ◽  
Electron Mass ◽  
Type Ii ◽  
Ir Detectors ◽  
Short Period ◽  
Type Ii Superlattices ◽  
Ir Detection ◽  
P Type ◽  
Electron Auger

AbstractThe effect of interface anisotropy on the electronic structure of InAs/GaSb type-II superlattices is exploited in the design of thin-layer superlattices for mid-IR detection threshold. The design is based on a theoretical envelope function model that incorporates the change of anion and cation species across InAs/GaSb interfaces, in particular, across the preferred InSb interface. The model predicts that a given threshold can be reached for a range of superlattice periods with InAs and GaSb layers as thin as a few monolayers. Although the oscillator strengths are predicted to be larger for thinner period superlattices, the absorption coefficients are comparable because of the compensating effect of larger band widths. However, larger intervalence band separations for thinner-period samples should lead to longer minority electron Auger lifetimes and higher operating temperatures in p-type SLs. In addition, the hole masses for thinner-period samples are on the order the free-electron mass rather than being effectively infinite for the wider period samples. Therefore, holes should also contribute to photoresponse. A number of superlattices with periods ranging from 50.6 to 21.2 Å for the 4 μm detection threshold were grown by molecular beam epitaxy based on the model design. Low temperature photoluminescence and photoresponse spectra confirmed that the superlattice band gaps remained constant at 330 meV although the period changed by the factor of 2.5. Overall, the present study points to the importance of interfaces as a tool in the design and growth of thin superlattices for mid-IR detectors for room temperature operation.

Sign in / Sign up

Export Citation Format

Share Document