Band Offsets of InAsxP1−X/InP Strained Layer Quantum Wells Grown by Lp-Movpe Using TBAs

1994 ◽  
Vol 358 ◽  
Author(s):  
M. Beaudoin ◽  
R.A. Masut ◽  
L. Isnard ◽  
P. Desjardins ◽  
A. Bensaada ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Absorption Spectra ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Energy Position ◽  
Band Offsets ◽  
Quantum Well Structures ◽  
Strained Layer ◽  
Transmission Electron ◽  
Metal Organic

ABSTRACTLow temperature optical absorption spectra are presented for a series of InAsxP1-x/InP strained layer multiple quantum well structures (0 < x = 0.35) grown by low pressure metal organic vapor phase epitaxy (LP-MOVPE) using trimethylindium (TMIn), tertiarybutylarsine (TBAs) and phosphine as precursors. The well widths and compositions in these structures are determined from high resolution x-ray diffraction and transmission electron microscopy. The absorption spectra are then analyzed by fitting the excitonic peak energy position with transition energies determined from a solution to the Schrödinger equation. We used the envelope function formalism with the Kane bands as the basis wavefunctions and included corrections for non parabolicity. From these fits and elasticity theory, both the bandgap of unstrained InAsxP1-x and the band offsets of these heterostructures are deduced self-consistently. The conduction band offsets are found between 72% and 75% of the total strained bandgap differences.

Approaches Toward Chemically Prepared Multiple Quantum Well Structures

1998 ◽  
Vol 545 ◽  
Author(s):  
S. B. Cronin ◽  
T. Koga ◽  
X. Sun ◽  
Z. Ding ◽  
S.-C. Huang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Well ◽  
Quantum Wells ◽  
Self Assembly ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Quantum Well Structures ◽  
Transmission Electron ◽  
2D System

AbstractAn enhanced thermoelectric figure of merit, ZT, has been predicted for Bi2Te3 in the form of 2-dimensional quantum wells. A new approach to making multiple quantum well (MQW) structures for thermoelectric applications utilizing a chemical intercalation technique is proposed and investigated. It is proposed that by starting from Li intercalated Bi2Te3 and Bi2Se3, the layers of these materials can be separated by chemical means. The layers of Bi2Te3 or Bi2 Se3 can then be restacked, by self-assembly, forming a non-periodic array of quantum wells. These chemically prepared MQWs are characterized by X-ray diffraction, SEM (scanning electron microscopy) and TEM (transmission electron microscopy) at various stages in the sample preparation to assess the degree to which the actual samples match the proposal. Experimental measurements of the Seebeck coefficient (S) and the electrical conductivity (σ) were performed over a range of temperatures for the initial bulk materials. It is found that some of the steps in the proposed fabrication have been achieved but still much improvement is needed before any practical thermoelectric 2D-system can be provided.

scholarly journals Luminescent Characteristics of InGaAsP/InP Multiple Quantum Well Structures by Impurity-Free Vacancy Disordering

2001 ◽  
Vol 692 ◽  
Author(s):  
J. Zhao ◽  
X. D. Zhang ◽  
Z. C. Feng ◽  
J. C. Deng ◽  
P. Jin ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Band Gap ◽  
Annealing Temperature ◽  
Multiple Quantum Well ◽  
Blue Shift ◽  
Multiple Quantum ◽  
Quantum Well Structures ◽  
Cladding Layer ◽  
Cap Layer ◽  
Free Vacancy

AbstractInGaAsP/InP multiple quantum wells have been prepared by Impurity-Free Vacancy Disordering (IFVD). The luminescent characteristics was investigated using photoluminescence (PL) and photoreflectance (PR), from which the band gap blue shift was observed. Si3N4, SiO2 and SOG were used for the dielectric layer to create the vacancies. All samples were annealed by rapid thermal anne aling (RTA). The results indicate that the band gap blue shift varies with the dielectric layers and annealing temperature. The SiO2 capping was successfully used with an InGaAs cladding layer to cause larger band tuning effect in the InGaAs/InP MQWs than the Si3N4 capping with an InGaAs cladding layer. On the other hand, samples with the Si3N4-InP cap layer combination also show larger energy shifts than that with SiO2-InP cap layer combination.

Composition and Strain Analysis of Semiconductor Heterostructures Using Thickness Fringes on Tem Images

1994 ◽  
Vol 332 ◽  
Author(s):  
H. Kakibayashi ◽  
R. Tsuneta ◽  
F. Nagata
Keyword(s):  
Multiple Quantum Well ◽  
Strain Analysis ◽  
Dynamical Theory ◽  
Multiple Quantum ◽  
Strained Layers ◽  
Quantum Well Structures ◽  
Depth Profiles ◽  
Transmission Electron ◽  
The Difference ◽  
Induced Defects

ABSTRACTComposition and strain depth profiles in heterostructures such as AlGaAs/GaAs, InGaAs/InP and SiGe/Si have been analyzed with a high resolution of 0.5 nm by using the thickness fringes in a transmission electron microscope image. This diagnostic method is found to successfully evaluate the compositional disordering caused by annealing multiple quantum well structures with abrupt interfaces, and determine the difference in strain distribution in the strained-layers with various lattice mismatches. Both the composition and strain depth-profiles are analyzed quantitatively by the image simulation based on the dynamical theory of electron diffraction. This method is also useful for sensitively detecting ion-implantation-induced defects.

scholarly journals Luminescent Characteristics of InGaAsP/InP Multiple Quantum Well Structures by Impurity-Free Vacancy Disordering

2001 ◽  
Vol 693 ◽  
Author(s):  
J. Zhao ◽  
X. D. Zhang ◽  
Z. C. Feng ◽  
J. C. Deng ◽  
P. Jin ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Band Gap ◽  
Annealing Temperature ◽  
Multiple Quantum Well ◽  
Blue Shift ◽  
Multiple Quantum ◽  
Quantum Well Structures ◽  
Cladding Layer ◽  
Cap Layer ◽  
Free Vacancy

AbstractInGaAsP/InP multiple quantum wells have been prepared by Impurity-Free Vacancy Disordering (IFVD). The luminescent characteristics was investigated using photoluminescence (PL) and photoreflectance (PR), from which the band gap blue shift was observed. Si3N4, SiO2 and SOG were used for the dielectric layer to create the vacancies. All samples were annealed by rapid thermal anne aling (RTA). The results indicate that the band gap blue shift varies with the dielectric layers and annealing temperature. The SiO2 capping was successfully used with an InGaAs cladding layer to cause larger band tuning effect in the InGaAs/InP MQWs than the Si3N4 capping with an InGaAs cladding layer. On the other hand, samples with the Si3N4-InP cap layer combination also show larger energy shifts than that with SiO2-InP cap layer combination.

Characterization of Nano-size Indium Cluster in InGaN/GaN Multiple QuantumWells with High Indium Composition

2003 ◽  
Vol 775 ◽  
Author(s):  
Hyung Koun Cho ◽  
Jeong Yong Lee
Keyword(s):  
Quantum Wells ◽  
Multiple Quantum Well ◽  
Localized States ◽  
Multiple Quantum ◽  
Emission Properties ◽  
Indium Composition ◽  
Transmission Electron ◽  
Integrated Intensity ◽  
Nano Size

AbstractWe report the effect of strain-induced indium clustering on the emission properties of InGaN/GaN multiple quantum wells grown with high indium composition by MOCVD. Nanosize indium clustering confirmed by high-resolution transmission electron microscopy results in the redshift of the emission peak and the increase of the integrated photoluminescence (PL) intensity. We found that strong carrier localization in indium clustering induces the increases of the activation energy of PL integrated intensity and the temperature independence of PL decay profiles. All these observations suggest structurally and optically that the improved emission properties in the InGaN/GaN multiple quantum well with high indium composition are associated with the localized states in the nano-size indium cluster.

Ion-channeling studies of InyGa1−yAs/GaAs strained-layer single and multiple quantum-well structures

1994 ◽  
Vol 143 (1-2) ◽  
pp. 29-39 ◽  
Author(s):  
G.W. Flemig ◽  
R. Brenn ◽  
E.C. Larkins ◽  
S. Bürkner ◽  
G. Bender ◽  
...  
Keyword(s):  
Quantum Well ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Quantum Well Structures ◽  
Strained Layer ◽  
Ion Channeling

High-Resolution X-ray Diffraction Analysis of p-Type Strained InGaAs/AlGaAs Multiple Quantum Well Structures

1999 ◽  
Vol 607 ◽  
Author(s):  
W. Shi ◽  
D. H. Zhang ◽  
T. Osotchan ◽  
P.H. Zhang ◽  
S. F. Yoon ◽  
...  
Keyword(s):  
Quantum Well ◽  
Doping Concentration ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Doping Density ◽  
Quantum Well Structures ◽  
As Doping ◽  
Transmission Electron ◽  
P Type

AbstractBe-doped InGaAs/AIGaAs multiple quantum well (MQW) structures, grown by solid-source molecular beam epitaxy with different doping concentration in the wells, were investigated by xray diffraction and transmission electron microscopy (TEM). Some features have been observed. (1) The MQW mean mismatch increases from 1.176 × 10−3 to 1.195 × 10−3 and 1.29 × 10−3 for the structures with doping concentration of 1 × 1017 cm−3, 1 × 1018cm−3and 2 × 1019 cm−3 in the wells, respectively. (2) The period of the MQW also increases with doping density. (3) The intensity of the first order satellite in the rocking curves decreases as the Be concentration is increased, indicating that indium diffusion in the heavily doped wells is likely more significant than that in the lightly doped ones. (4) The full width at half maximum of the zero-order satellite peak becomes widened as doping concentration increases, indicating that high Be-doping in the well likely deteriorates the interfaces of the multiple quantum well stacks. In addition, TEM measurement is conducted and clear pictures on well and barrier layers of the structures are observed. The information obtained is of great value for the design of p-doped quantum well infrared photodetectors.

Design and Optical Characterization of Novel InGaN/GaN Multiple Quantum Well Structures by Metal Organic Vapor Phase Epitaxy

2013 ◽  
Vol 52 (8S) ◽  
pp. 08JL10 ◽  
Author(s):  
Liyang Zhang ◽  
Ruben R. Lieten ◽  
Magdalena Latkowska ◽  
Michał Baranowski ◽  
Robert Kudrawiec ◽  
...  
Keyword(s):  
Quantum Well ◽  
Vapor Phase ◽  
Multiple Quantum Well ◽  
Optical Characterization ◽  
Vapor Phase Epitaxy ◽  
Multiple Quantum ◽  
Quantum Well Structures ◽  
Organic Vapor ◽  
Metal Organic

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.

Sign in / Sign up

Export Citation Format

Share Document