Submicron Scale Interface Roughness in Quantum Wells Observed by High-Resolution Cathodoluminescence Microscopy

1992 ◽  
Vol 280 ◽  
Author(s):  
Tom Murashita ◽  
Kazumi Wada ◽  
Kiyoshi Kanisawa ◽  
Naohisa Inoue
Keyword(s):  
Growth Rate ◽  
High Resolution ◽  
Quantum Wells ◽  
High Substrate Temperature ◽  
Interface Roughness ◽  
Thickness Variation ◽  
Single Quantum ◽  
Single Quantum Well ◽  
Smooth Interface ◽  
Submicron Scale

ABSTRACTA single quantum well (SQW) is grown at a high substrate temperature and low growth rate (HTLR growth) in order to reduce interface roughness. The lateral well thickness variation in the SQW is characterized by the cathodolumincscence microscopy. It is clarified that HTLR growth can be applied to make a smooth interface for advanced devices.

Single Quantum Well Heterostructures of MgZnO/ZnO/MgZnO on C-Plane Sapphire

2000 ◽  
Vol 623 ◽  
Author(s):  
S. Choopun ◽  
D. M. Chalk ◽  
W. Yang ◽  
R. D. Vispute ◽  
S. B. Ogale ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Reference Sample ◽  
Blue Shift ◽  
Growth Conditions ◽  
Interface Roughness ◽  
Single Quantum ◽  
Single Quantum Well ◽  
Quantum Size ◽  
Well Model

AbstractThe single quantum well heterostructures of MgZnO/ZnO/MgZnO were grown on c-plane sapphire substrate by pulsed laser deposition. The well width was varied from 10 nm to 40 nm by controlling the deposition rate via number of laser pulsed on ZnO target. Using photoluminescence spectroscopy, we have observed a blue shift with respect to a thick ZnO reference sample when the well width was decreased. These results were fitted with calculations based on the simple square well model using the appropriate electron and holes effective masses. The quantized-energy and band offset as a function of well width, growth conditions, interface roughness, and possible quantum size effects on the quantum wells are discussed.

Spontaneous Lateral Modulations in InAlAs Buffer Layers Grown by MBE on InP Substrates

1995 ◽  
Vol 417 ◽  
Author(s):  
F. Peiró ◽  
A. Cornet ◽  
J. C. Ferrer ◽  
J. R. Morante ◽  
G. Halkias ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Molecular Beam ◽  
Buffer Layers ◽  
Single Quantum ◽  
X Ray Diffraction ◽  
Single Quantum Well ◽  
Quantum Well Structures ◽  
X Ray ◽  
Transmission Electron ◽  
Inp Substrates

AbstractTransmission Electron Microscopy (TEM) and X-ray Diffraction (XRD) have been used to analyze the spontaneous appearance of lateral composition modulations in InyAl1−yAs (yIn.≅ 50%) buffer layers of single quantum well structures grown by molecular beam epitaxy on exact and vicinal (100) InP substrates, at growth temperatures in the range of 530°C–580°C. The influence of the growth temperature, substrate misorientation and epilayer mismatch on the InAlAs lateral modulation is discussed. The development of a self-induced quantum-wire like morphology in the In0.53Ga0.47As single quantum wells grown over the modulated buffers is also commented on.

InGaAs/GaAs strained single quantum well characterization by high resolution X-ray diffraction

1993 ◽  
Vol 126 (1) ◽  
pp. 144-150 ◽  
Author(s):  
C. Ferrari ◽  
M.R. Bruni ◽  
F. Martelli ◽  
M.G. Simeone
Keyword(s):  
High Resolution ◽  
Quantum Well ◽  
Single Quantum ◽  
X Ray Diffraction ◽  
Single Quantum Well ◽  
X Ray

scholarly journals Strain state in single quantum well GaAs/1ML-InAs/GaAs(100) analysed by high-resolution X-ray diffraction

1998 ◽  
Vol 41 (6) ◽  
pp. 623-628 ◽  
Author(s):  
Y Zheng ◽  
J. C Boulliard ◽  
B Capelle ◽  
A Lifchitz ◽  
S.
Keyword(s):  
High Resolution ◽  
Quantum Well ◽  
Strain State ◽  
Single Quantum ◽  
X Ray Diffraction ◽  
Single Quantum Well ◽  
X Ray

Grazing Incidence X-Ray Scattering Studies of Single Quantum Wells

1987 ◽  
Vol 31 ◽  
pp. 155-160
Author(s):  
S. Bates ◽  
P.D. Hatton ◽  
C.A. Lucas ◽  
T.W. Ryan ◽  
S.J. Miles ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Lattice Mismatch ◽  
Thick Layer ◽  
Grazing Incidence ◽  
Single Quantum ◽  
Individual Layer ◽  
Single Quantum Well ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

AbstractX-ray scattering techniques at grazing incidence have been used to characterize single quantum well hetero–structures. Double–and triple-axis diffractometry has been used to determine lattice mismatch and layer thickness of a 250Å thick layer of AlInAs grown by MBE on an InP substrate and capped by a 45Å GaAs layer. Reflectivity measurements in the triple – crystal mode permit accurate measurement of individual layer thicknesses, relative electron density and interface roughnesses on the Angstrom level.

INSIGHTS ON THE BOUND STATES IN THE STRAINED CdSe–ZnSe SINGLE-QUANTUM WELLS

2008 ◽  
Vol 22 (13) ◽  
pp. 2055-2069 ◽  
Author(s):  
NACIR TIT ◽  
IHAB M. OBAIDAT
Keyword(s):  
Quantum Wells ◽  
Valence Band ◽  
Quantum Confinement ◽  
Bound States ◽  
Axial Strain ◽  
Bound State ◽  
Band Offset ◽  
Single Quantum ◽  
Valence Band Offset ◽  
Single Quantum Well

The bound states in the (CdSe) Nw– ZnSe (001) single quantum well are investigated versus the well width (Nw monolayers) and the valence-band offset (VBO). The calculation, based on the sp3s* tight-binding method which includes the spin-orbit interactions, is employed to calculate the band-gap energy (Eg), quantum-confinement energy (EQ), and band structures. It is found that the studied systems possess a vanishing valence-band offset ( VBO ≃ 0) in consistency with the common-anion rule, and a large conduction band offset of about ( CBO ≃ 1 eV ); both of which made the electronic confinement become predominant. The bi-axial strain, on the other hand, remains to control the hole states. Namely, the two highest (spin-degenerate) hole states are found to localize at the two interfaces due to the formation of two similar strain-induced potential dips at these interfaces, each of depth equal to the strain energy ~35 meV. More importantly, the ultrathin CdSe wells (with Nw ≤ 4 monolayers) are found to contain only a single (spin-degenerate) bound state; but by increasing the well width further, a new (spin-degenerate) bound state falls into the well every time Nw hits a multiple of 4 monolayers (more specifically, for 4n+1 ≤ Nw ≤ 4 (n+1), the number of bound states is (n+1), where n is an integer). The rule governing the variation of the quantum-confinement energy EQ versus the well width Nw has been derived. Our theoretical results are in excellent agreement with the available experimental photoluminescence data.

Quantitative characterization of the interface roughness of (GaIn)As quantum wells by high resolution STEM

Micron ◽  
2015 ◽  
Vol 79 ◽  
pp. 1-7 ◽  
Author(s):  
H. Han ◽  
A. Beyer ◽  
K. Jandieri ◽  
K.I. Gries ◽  
L. Duschek ◽  
...  
Keyword(s):  
High Resolution ◽  
Quantum Wells ◽  
Interface Roughness ◽  
Quantitative Characterization

Low Temperature Growth of Gaas Quantum Well Lasers by Modulated Beam Epitaxy

1991 ◽  
Vol 228 ◽  
Author(s):  
S. Xin ◽  
K. F. Longenbach ◽  
C. Schwartz ◽  
Y. Jiang ◽  
W. I. Wang
Keyword(s):  
Low Temperature ◽  
Quantum Well ◽  
Substrate Temperature ◽  
Quantum Wells ◽  
High Growth ◽  
Quantum Well Lasers ◽  
Single Quantum ◽  
Single Quantum Well ◽  
Temperature Growth ◽  
Low Temperature Growth

ABSTRACTGaAs single quantum well lasers have been successfully grown at low temperatures by a modulated beam epitaxy process in which the Al/Ga flux is held constant while the As flux is periodically shut off to produce a metal-rich surface. Devices grown at a substrate temperature of 500 °C exhibit threshold current densities below 1 kA/cm2. This value is lower than normally grown low temperature lasers and is the lowest achieved by any low substrate temperature growth technique. In addition, low temperature (10 K) photoluminescence of single quantum wells grown with this technique exhibit full-width half maximum values, comparable to that attainable by higher temperature growth techniques. The improved quality of these low temperature grown quantum structures is attributed to both a smoothing of the growth front and a reduction of excess As during the modulated beam epitaxy process. The high growth rates and less frequent shutter operation of this technique make it a more practical than migration enhanced epitaxy or atomic layer epitaxy for low temperature growth.

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