OMVPE Growth of GalnAs/InP Quantum Well Structures

1987 ◽  
Vol 102 ◽  
Author(s):  
G. B. Stringfellow
Keyword(s):  
Binding Energy ◽  
Quantum Well ◽  
Quantum Wells ◽  
Vapor Phase ◽  
Atmospheric Pressure ◽  
Growth Conditions ◽  
Binding Energies ◽  
Optimum Conditions ◽  
Quantum Well Structures ◽  
Maximum Value

ABSTRACTInP/GalnAs/InP quantum well structures have been grown using atmospheric pressure organometallic vapor phase epitaxy (AP-OMVPE). The optimum conditions for growth of extremely abrupt interfaces were studied. The optimum orientation was exactly (100). The growth had to be interrupted for 40 seconds at the first interface and 2 minutes at the 2nd interface to obtain the most abrupt interfaces. The narrowest photoluminescence half widths were obtained at the lowest values (31) of V/III ratio in the input vapor phase. These growth conditions allow the growth of wells as thin as <10Å with photoluminescence (PL) spectra consisting of doublets or triplets. The extremely narrow peaks correspond to regions of the quantum well differing in thickness by a single monolayer. The energy separations of the neighboring peaks are found to increase with decreasing well width until, at a thickness of approximately 12 Å, the separation begins to decrease rapidly with decreasing well width. The exciton binding energies in the quantum wells have also been measured using thermally modulated PL. The binding energy is found to increase with decreasing well width until a maximum value of approximately 17 meV is measured for a nominal well width of approximately 13 Å. For thinner wells the exciton binding energy is found to decrease with decreasing well width.

SHALLOW DONORS IN A COUPLED TRIPLE GRADED QUANTUM WELL UNDER THE ELECTRIC AND MAGNETIC FIELDS

2006 ◽  
Vol 13 (04) ◽  
pp. 397-401 ◽  
Author(s):  
E. KASAPOGLU ◽  
H. SARI ◽  
I. SÖKMEN
Keyword(s):  
Binding Energy ◽  
Quantum Well ◽  
Quantum Wells ◽  
Electric Fields ◽  
Growth Direction ◽  
Physical Parameters ◽  
Donor Impurity ◽  
Quantum Well Structures ◽  
Hydrogenic Donor Impurity ◽  
Electric And Magnetic Fields

The binding energy of the donor in three different shaped triple graded GaAs -( Ga , Al ) As quantum wells which is obtained by changing the depth of the central-well potential (Vo) is calculated by using a variational approach. The results have been obtained in the presence of uniform magnetic and electric fields applied along the growth direction as a function of the impurity position. In addition, we also give the binding energy of the hydrogenic donor impurity for triple square quantum wells having the same physical parameters with triple graded quantum well structures in order to see the effect of different geometric confinements on the donor impurity binding energy.

Emission Mechanisms in UV Emitting GaN/AlN Multiple Quantum Well Structures

2003 ◽  
Vol 798 ◽  
Author(s):  
Madalina Furis ◽  
Alexander N. Cartwright ◽  
Hong Wu ◽  
William J. Schaff
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Temperature Dependence ◽  
Multiple Quantum Well ◽  
Activation Energies ◽  
Inhomogeneous Broadening ◽  
Binding Energies ◽  
Multiple Quantum ◽  
Quantum Well Structures ◽  
Donor And Acceptor

ABSTRACTThe need for efficient UV emitting semiconductor sources has prompted the study of a number of heterostructures of III-N materials. In this work, the temperature dependence of the photoluminescence (PL) properties of UV-emitting GaN/AlN multiple quantum well (MQW) heterostructures were investigated in detail. In all samples studied, the structure consisted of 20 GaN quantum wells, with well widths varying between 7 and 15 Å, clad by 6nm AlN barriers, grown on top of a thick AlN buffer that was deposited on sapphire by molecular beam epitaxy. The observed energy corresponding to the peak of the emission spectrum is in agreement with a model that includes the strong confinement present in these structures and the existence of the large built-in piezoelectric field and spontaneous polarization present inside the wells. The observed emission varies from 3.5 eV (15 Å well) to 4.4 eV (7 Å well). Two activation energies associated with the photoluminescence quenching are extracted from the temperature dependence of the time-integrated PL intensity. These activation energies are consistent with donor and acceptor binding energies and the PL is dominated by recombination involving carriers localized on donor and/or acceptor states.Moreover, the temperature dependence of the full width at half-maximum (FWHM) of the PL feature indicates that inhomogeneous broadening dominates the spectrum at all temperatures. For the 15 and 13 Å wells, we estimate that the electron-phonon interaction is responsible for less than 30% of the broadening at room temperature. This broadening is negligible in the 9 Å wells over the entire temperature range studied. Well width fluctuations are primarily responsible for the inhomogeneous broadening, estimated to be of the order of 250meV for one monolayer fluctuation in well width.

-ORIENTED GaAs/AlGaAs AND InGaAs/GaAs QUANTUM WELL STRUCTURES FABRICATED BY MOVPE AND THEIR OPTICAL AND STRAIN-INDUCED PIEZOELECTRIC PROPERTIES

2000 ◽  
Vol 10 (01) ◽  
pp. 93-101
Author(s):  
SOOHAENG CHO ◽  
A. SANZ-HERVÁS ◽  
JONGSEOK KIM ◽  
A. MAJERFELD ◽  
B. W. KIM
Keyword(s):  
Quantum Well ◽  
Electric Fields ◽  
Vapor Phase ◽  
Atmospheric Pressure ◽  
Piezoelectric Properties ◽  
Single Quantum ◽  
Single Quantum Well ◽  
Quantum Well Structures ◽  
Gaas Substrates ◽  
Pl Emission

We report our recent results on the growth and properties of GaAs/AlGaAs and strained InGaAs/GaAs quantum well (QW) structures grown on (111)A GaAs substrates by atmospheric-pressure metalorganic vapor phase epitaxy. We have fabricated 25-period GaAs/AlGaAs multiquantum well structures with good crystal quality, high photoluminescence (PL) emission intensity and monolayer (ML) well width fluctuation. We also present the optical and piezoelectric properties of strained InGaAs/GaAs single quantum well structures grown on (111)A GaAs. Photoreflectance spectroscopy has been performed to analyze not only the excitonic transitions, but also the Franz-Keldysh oscillations to obtain the electric fields in the well and barriers, which are necessary to determine the actual QW potential profile and, thereby, to properly interpret the properties of the structures. A PL linewidth of 9.7 meV has been also achieved, which corresponds to a 1 ML interfacial roughness for an In0.14Ga0.86As well with a 40 Å width.

Luminescence Studies of MBE Grown SI/SIGE Quantum Wells

1993 ◽  
Vol 298 ◽  
Author(s):  
M. Gail ◽  
J. Brunner ◽  
U. Menczigar ◽  
A. Zrenner ◽  
G. Abstreiter
Keyword(s):  
Binding Energy ◽  
Quantum Well ◽  
Quantum Wells ◽  
Elevated Temperatures ◽  
Variational Calculation ◽  
Exciton Binding Energy ◽  
Quantum Well Structures ◽  
Mass Approximation ◽  
Wide Range ◽  
Good Agreement

AbstractWe report on detailed luminescence studies of MBE grown Si/Si1-xGex quantum well structures. Both well width and composition is varied over a wide range. Bandgap photoluminescence is observed for all samples grown at elevated temperatures. The measured bandgap energies are in good agreement with subband calculations based on effective mass approximation and taking into account the segregation of Ge atoms during growth. Diffusion is found to limit quantum well (QW) growth with Ge-contents above 35% at high temperatures. The photoluminescence signals are detected up to about 100K and can be attributed to interband transitions of free excitons. We also present investigations of the exciton binding energy as a function of well width and composition. The observed shift of the exciton binding energy is compared with results of a variational calculation. A distinct onset in photocurrent and electroluminescence up to 200 K are observed in quantum well diodes.

Optical Properties of AlGaN Quantum Well Structures

1999 ◽  
Vol 595 ◽  
Author(s):  
Hideki Hirayama ◽  
Yasushi Enomoto ◽  
Atsuhiro Kinoshita ◽  
Akira Hirata ◽  
Yoshinobu Aoyagi
Keyword(s):  
Optical Properties ◽  
Quantum Well ◽  
Quantum Wells ◽  
Vapor Phase ◽  
Wide Bandgap ◽  
Near Band Edge ◽  
Quantum Well Structures ◽  
Al Content ◽  
Pl Emission ◽  
High Al Content

AbstractWe demonstrate 230-250 nm efficient ultraviolet (UV) photoluminescence (PL) from AlN(AlGaN)/AlGaN multi-quantum-wells (MQWs) fabricated by metalorganic vapor-phase-epitaxy (MOVPE). Firstly, we show the PL properties of high Al content AlGaN bulk (Al content: 85-95%) emitting from near band-edge. We systematically investigated the PL properties of AlGaN-MQWs consisting of wide bandgap AlGaN (Al content: 53-100%) barrier. We obtained efficient PL emission of 234 and 245 nm from AlN/Al0.18Ga0.82N and Al0.8Ga0.2N/Al0.18Ga0.82N MQWs, respectively, at 77 K. The optimum value of well thickness was approximately 1.5 nm. The emission from the AlGaN MQWs were several tens of times stronger than that of bulk AlGaN. We found that the most efficient PL is obtained at around 240 nm from AlGaN MQWs with Al0.8Ga0.2N barriers. Also, we found that the PL from AlGaN MQW is as efficient as that of InGaN QWs at 77 K.

Highly Strained InAsxPl-X/InP Quantum wells Prepared by Flow Modulation Epitaxy

1989 ◽  
Vol 145 ◽  
Author(s):  
R. P. Schneider ◽  
B. W. Wessels
Keyword(s):  
Quantum Wells ◽  
Atmospheric Pressure ◽  
Growth Conditions ◽  
Photoluminescence Spectra ◽  
Quantum Well Structures ◽  
Flow Modulation ◽  
Modulation Techniques ◽  
Lateral Extent ◽  
Highly Strained ◽  
Lattice Matched

AbstractFlow modulation techniques have been used to prepare highly strained InAsxPl-x/InP quantum well structures in an atmospheric pressure organometallic vapor phase epitaxial reactor. The compositions of the pseudomorphic wells ranged from x=0.40 to 0.74, corresponding to biaxial compressive strains of 1.3-2.4%. Well thicknesses ranged from 2 to 26 monolayers. The flow modulation growth conditions were found to have a strong influence on interface formation in the wells. For wells grown under optimized modulation conditions, low-temperature photoluminescence spectra revealed peak-splitting of the emission from the thinnest wells. This splitting is attributed to emission from regions in the wells with atomically smooth interfaces over areas greater in lateral extent than the exciton diameter. The full-width at half-maximum of the peaks is in the 6-15 meV range, comparable to the best reported values for lattice- matched InGaAs(P)/InP quantum wells grown by any technique, and is independent of well thickness or composition.

Doping effect on exciton binding energy in semiconductor quantum well

2017 ◽  
Vol 31 (03) ◽  
pp. 1750004
Author(s):  
Yongkai Li ◽  
Shuangbo Yang
Keyword(s):  
Binding Energy ◽  
Quantum Well ◽  
Quantum Wells ◽  
Doping Concentration ◽  
Binding Energies ◽  
The Self ◽  
Mass Approximation ◽  
Self Consistent ◽  
Semiconductor Quantum Well ◽  
Si Doped

By solving the Schrödinger equation and Poisson’s equation self-consistently, we have calculated the electronic structure for Si-doped GaAs/Al[Formula: see text]Ga[Formula: see text]As quantum well system at [Formula: see text] K in the effective mass approximation. We obtain the self-consistent potentials, eigen-envelope functions and the subband energies for different doping concentrations and for different thicknesses of the doping layer. The binding energies of exciton in GaAs/Al[Formula: see text]Ga[Formula: see text]As quantum wells under different doping conditions are calculated by using a variational method. And the variation of the binding energy with the thickness of the doped layer and the doping concentration is analyzed. It is found that at a given doping concentration, with the increase of thickness of the doping layer, the self-consistent potential becomes wider and more shallow, the binding energy of exciton decreases. At a given thickness of the doping layer, with the increase of the doping concentration, the self-consistent potential becomes narrower and deeper, the binding energy of exciton increases.

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