InGaAs/GaAsSb Heterostructures: Aluminum-Free Intersubband Devices

2009 ◽  
Vol 1195 ◽  
Author(s):  
Michele Nobile ◽  
Gottfried Strasser ◽  
Hermann Detz ◽  
Elvis Mujagic ◽  
Aaron Andrews ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Quantum Cascade Laser ◽  
Multiple Quantum Well ◽  
Wavelength Region ◽  
Threshold Current ◽  
Multiple Quantum ◽  
Material System ◽  
Quantum Cascade ◽  
Intersubband Absorption

AbstractAn experimental study on mid-infrared intersubband absorption in InGaAs/GaAsSb multiple quantum wells grown lattice-matched to InP substrates by molecular beam epitaxy is presented. Intersubband absorption in a broad wavelength region (5.8 - 11.6 μm) is observed in multiple quantum well samples with well widths ranging between 4.5 and 12 nm. A conduction band offset at the InGaAs/GaAsSb heterointerface of 360 meV gives an excellent agreement between the theoretically calculated ISB transition energies and the Fourier-transform infrared spectroscopy measurements over the whole range of well widths under investigation. Two kinds of intersubband devices based on the InGaAs/GaAsSb material system are presented: a quantum well infrared photodetector operating at a wavelength of 5.6μm and an aluminum-free quantum cascade laser. The presented quantum cascade laser emits at a wavelength of 11.3 μm, with a threshold current density of 1.7 kA/cm2 at 78 K.

EFFECT OF PSEUDOMORPHIC MULTIPLE QUANTUM WELL LAYERS ON CHARACTERISTICS OF UNCOOLED ELECTROLUMINESCENT DIODE

2009 ◽  
Vol 23 (32) ◽  
pp. 5859-5865
Author(s):  
JAE-HO HAN ◽  
ZAIL LHEE ◽  
SUNG-WOONG PARK
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Communication Systems ◽  
Multiple Quantum Well ◽  
Threshold Current ◽  
Semiconductor Diode ◽  
Multiple Quantum ◽  
Growth Step ◽  
Semiconductor Diode Laser ◽  
Strained Quantum Well

We have fabricated and characterized the uncooled light emitting device having a pseudomorphic structure of multiple quantum wells. The effect of numbers of compressively strained quantum well layers on the semiconductor diode laser characteristics was experimentally demonstrated, depending on room and high temperatures. In addition to the automatically embedded absorptive grating which can reduce the epitaxial growth step, the laser performance can be optimized for both threshold current and differential slope efficiency when the quantum well numbers are reduced to five layers for optical communication systems.

scholarly journals Photo- and cathodoluminescence investigations of piezoelectric GaN/AlGaN quantum wells

2000 ◽  
Vol 639 ◽  
Author(s):  
E.M. Goldys ◽  
M. Godlewski ◽  
M.R. Phillips ◽  
A.A. Toropov
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Electric Fields ◽  
Free Exciton ◽  
Multiple Quantum Well ◽  
Depth Profiling ◽  
Multiple Quantum ◽  
Recombination Mechanism ◽  
Decay Times ◽  
Piezoelectric Fields

ABSTRACTWe have examined multiple quantum well AlGaN/GaN structures with several quantum wells of varying widths. The structures had strain-free quantum wells and strained barriers. Strong piezoelectric fields in these structures led to a large red shift of the PL emission energies and long decay times were also observed. While the peak energies could be modelled using the effective mass approximation, the calculated free exciton radiative lifetimes were much shorter than those observed in experiments, indicating an alternative recombination mechanism, tentatively attributed to localised excitons. Cathodoluminescence depth profiling revealed an unusually small penetration range of electrons suggesting that electron-hole pairs preferentially remain within the multiple quantum well region due to the existing electric fields. Spatial fluctuations of the cathodoluminescence intensity were also observed.

Experimental study on the mechanism governing spectral shifts in low power 670 nm AlGaInP multiple quantum well (MQW) laser diodes over temperature range 5–45 °C

2016 ◽  
Vol 94 (7) ◽  
pp. 640-644 ◽  
Author(s):  
Santosh Chackrabarti ◽  
Dhrub Sharma ◽  
Shereena Joseph ◽  
Tho-alfiqar A. Zaker ◽  
A.K. Hafiz ◽  
...  
Keyword(s):  
Quantum Well ◽  
Low Power ◽  
Band Gap ◽  
Characteristic Temperature ◽  
Multiple Quantum Well ◽  
Laser Diodes ◽  
Threshold Current ◽  
Multiple Quantum ◽  
Spectral Shifts ◽  
Band Gap Narrowing

We report on the temperature-dependent spectral shifts in low power 670 nm AlGaInP multiple quantum well red laser diodes due to band gap narrowing at room temperatures (5–45 °C). The spectral shift mechanism is explored with a threshold current density of 11.41 kA/cm2 and a good characteristic temperature of 114 K. The photoluminescence peak intensity shifts towards higher wavelengths and the full width at half maximum increases with increase in temperature from 5 to 45 °C. We use a Hamiltonian system considering the effective mass approximation to formulate the carrier concentrations. The band gap narrowing value determined by a simple formula amounts to 59.15 meV and displays N1/3 dependence at higher densities. The carrier density dependence conveys that the redshift of the spectral emission is due to band gap narrowing.

PHOTOCONDUCTIVITY, PHOTOREFLECTANCE AND PHOTOLUMINESCENCE OF GaAs-AlAs MULTIPLE QUANTUM WELLS

1985 ◽  
Vol 56 ◽  
Author(s):  
H. NEFF ◽  
K. J. BACHMANN ◽  
W. D. LAIDIG
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Heavy Hole ◽  
Multiple Quantum Well ◽  
Light Hole ◽  
Multiple Quantum ◽  
Indirect Transition ◽  
Temperature Dependent ◽  
Direct Inter ◽  
Phonon Absorption

AbstractEmploying temperature dependent photoconductivity, photoluminescence and photoreflectivity measurements, we have analyzed a GaAs-AlAs multiple quantum well. The above optical techniques clearly resolve the fundamental inter-subband transitions, including heavy hole-light hole splittings. At T < 60K an anomalously high photoconductivity was discovered below the direct inter-subband transitions and is attributed tentatively to the presence of extrinsic interface states within the bandgap. For T > l00K the fundamental indirect transition was discovered and associated with LO (L) - phonon absorption.

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