Growth and Characterization Of GexSi1−x/ Si Multiple Quantum Well Structures

1992 ◽  
Vol 263 ◽  
Author(s):  
D.W. Greve ◽  
R. Misra ◽  
M.A. Capano ◽  
T.E. Schlesinger
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Multiple Quantum Well ◽  
Small Variation ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
High Quality ◽  
Quantum Well Structures ◽  
X Ray

ABSTRACTWe report on the growth and characterization of multiple quantum well structures by UHV/ CVD epitaxy. X- ray diffraction is used to verify the expected layer periodicity and to determine the quantum well thickness. Photoluminescence measurements show peaks which we associate with recombination of excitons in the quantum wells. The measurements are consistent with high quality layers with small variation in quantum well thickness across a wafer.

High Resolution X-ray Diffraction Characterization of [111]B Oriented InGaAs/GaAs Mqw Structures

1995 ◽  
Vol 39 ◽  
pp. 439-448
Author(s):  
A Sanz-Hervas ◽  
A Sacedón ◽  
E.J Abril ◽  
J.L Sanchez-Rojas ◽  
C. Villar ◽  
...  
Keyword(s):  
High Resolution ◽  
Quantum Well ◽  
Structural Information ◽  
Multiple Quantum Well ◽  
Growth Conditions ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Quantum Well Structures ◽  
X Ray

In this work we apply high-resolution X-ray diffractometry to the study of InGaAs/GaAs multiple quantum well structures on (001) and(lll)B GaAs substrates. The samples consisted of p-i-n diodes with a multiple quantum well embedded in the i-region and were simultaneously grown on (001) and (111)B substrates by molecular beam epitaxy. For the characterization we have used symmetric and asymmetric reflections at different azimuthal positions. The interpretation of the diffraction profiles has been possible thanks to our recently developed simulation model, which allows the calculation of any reflection regardless of the substrate orientation. X-ray results about composition and thickness are very similar in the samples simultaneously grown on both orientations as expected from our specific growth conditions. The information obtained from X-ray characterization is consistent with the results of photoluminescence and photocurrent measurements within the experimental uncertainty of the techniques. In (lll)B samples, X-ray diffractometry provides structural information which cannot be easily obtained from optical characterization techniques.

MBE growth and characterization of high-quality strained multiple quantum well structures

1997 ◽  
Vol 175-176 ◽  
pp. 873-876 ◽  
Author(s):  
A.Z. Li ◽  
Y. Zhao ◽  
Y.L. Zheng ◽  
G.T. Chen ◽  
G.P. Ru ◽  
...  
Keyword(s):  
Quantum Well ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
High Quality ◽  
Mbe Growth ◽  
Quantum Well Structures

X-Ray Scattering (Modeling and Experiment) of InxGa1-xAs/GaAs Multiple Quantum Wells

1987 ◽  
Vol 103 ◽  
Author(s):  
Jichai Jeong ◽  
J. C. Lee ◽  
M. A. Shahid ◽  
T. E. Schlesinger ◽  
A. G. Milnes
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Quantum Well Structures ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Good Agreement

ABSTRACTX-ray diffraction, transmission electron microscopy (TEM), and photoluminescence measurements have been made on strained InxGa1-xAs/GaAs quantum well structures. The well widths measured from TEM are 187, 115 and 69 Å for an interrupted growth, and 218, 126, 60 Å for a non-interrupted growth. In the measured x-ray diffraction patterns, the Pendellosung fringes due to GaAs barriers are modulated by a broad weak peak mostly coming from the thickest InxGa1-xAs well layer and is fairly symmetric for the noninterrupted sample. For the interrupted quantum well, the x-ray diffraction pattern is less symmetric, since there is further modulation by another broader and weaker peak. This results show that the In content in the InxGa1-xAs well layers are not well controlled for the interrupted quantum well. Using actual thickness measured from TEM, x-ray diffraction patterns are calculated and good agreement is obtained between the measured and the calculated x-ray diffraction patterns. The three strained InxGa1-xAs/Gaks quantum wells grown without interruption produce high intensity and narrow full-width at half-maximum (FWHIM) of 2.9 meV of the photoluminescence peak. The photoluminescence peaks for the interrupted quantum well are relatively broad and asymmetric, and have lower intensities, indicating that better quality InxGa1-xAs/GaAs quantum wells can be grown without interruption.

Laser-Modified Chemical Beam Epitaxy of InGaAs/GaAs Multiple Quantum Wells Using Tris-Dimethylaminoarsenic

1994 ◽  
Vol 354 ◽  
Author(s):  
H.K. Dong ◽  
N.Y. Li ◽  
C.W. Tu
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Laser Irradiation ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Chemical Beam Epitaxy ◽  
Quantum Well Structures ◽  
X Ray ◽  
Strained Quantum Well ◽  
First Time

AbstractWe report for the first time laser-modified chemical beam epitaxy (CBE) of InGaAs/GaAs multiple quantum well (MQW) structures using trimethylindium (TMIn), triethylgallium (TEGa), and tris-dimethylaminoarsenic (TDMAAs), a safer alternative to arsine. X-ray rocking curve (XRC) and low-temperature photoluminescence (PL) measurements were used to characterize the pseudomorphic strained quantum well structures. As determined by the X-ray simulation, laser irradiation during the InGaAs well growth was found to enhance the InGaAs growth rate and reduce the indium concentration in the substrate temperature range studied, 440-S00°C, where good interfaces can be achieved. We attribute these changes to laser-enhanced decomposition of TEGa and laser-enhanced desorption of TDMAAs. With laser irradiation, lateral variation of PL exciton peaks was observed, and the PL peaks became narrower.

Characterization of Doped GexSi1−x Multiple Quantum well Structures for far- IR Detectors

1994 ◽  
Vol 299 ◽  
Author(s):  
D. W. Greve ◽  
R. Misra ◽  
R. Strong ◽  
T.E. Schlesinger
Keyword(s):  
Quantum Well ◽  
Multiple Quantum Well ◽  
Normal Incidence ◽  
Multiple Quantum ◽  
Free Carrier Absorption ◽  
Ir Detectors ◽  
Quantum Well Structures ◽  
X Ray ◽  
Carrier Absorption

AbstractDoped GexSi1−x/Si multiple quantum well structures have been grown by UHV/CVD and characterized by various techniques. SIMS and X- ray confirm the intended modulation of germanium and boron concentrations, and photoluminescence has been used to assess material quality. Strong free- carrier absorption has been observed at normal incidence in some samples. The results suggest that doping intermediate between 4 × 1018 cm−3 and 4 × 1019 cm−3 is necessary for useful detectors.

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.

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