Growth and Characterization of Zn1-xMnxSe1-ySy Epilayers and Related Heterostructures

1996 ◽  
Vol 452 ◽  
Author(s):  
F. S. Flack ◽  
N. Samarth ◽  
F. Semendy
Keyword(s):  
Quantum Wells ◽  
Energy Gap ◽  
Spin Fluctuations ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Double Crystal ◽  
Wide Range ◽  
Confining Layers

AbstractWe describe the growth of (Zn,Mn)(S,Se) epitaxial layers of high structural quality on (100) GaAs substrates. Double crystal x-ray diffraction (DCXRD) measurements indicate that quaternary epilayers nearly lattice-matched with GaAs are characterized by DCXRD curves with a foil width at half maximum in the range 30 – 60 arc seconds. Photoluminescence (PL) spectroscopy is employed to map the variation of the energy gap of the quartenary alloys over a wide range of alloy compositions. Finally, temperature dependent PL is used to examine the viability of (Zn,Mn)(S,Se) alloys as confining layers for ZnSe and (Zn,Cd)Se quantum wells. While efficient exciton confinement is demonstrated through the observation of robust PL from such quantum wells up to high temperatures, the renormalization of the quartenary band gap by spin fluctuations leads to a rapid decrease in confinement with increase in temperature.

scholarly journals Photoreflectance Spectroscopy Characterization of Ge/Si0.16Ge0.84Multiple Quantum Wells on Ge Virtual Substrate

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Hung-Pin Hsu ◽  
Pong-Hong Yang ◽  
Jeng-Kuang Huang ◽  
Po-Hung Wu ◽  
Ying-Sheng Huang ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Interband Transition ◽  
Multiple Quantum Well ◽  
Chemical Vapor ◽  
Detailed Comparison ◽  
Multiple Quantum ◽  
Temperature Dependent ◽  
Wide Range ◽  
Quantum Confined

We report a detailed characterization of a Ge/Si0.16Ge0.84multiple quantum well (MQW) structure on Ge-on-Si virtual substrate (VS) grown by ultrahigh vacuum chemical vapor deposition by using temperature-dependent photoreflectance (PR) in the temperature range from 10 to 300 K. The PR spectra revealed a wide range of optical transitions from the MQW region as well as transitions corresponding to the light-hole and heavy-hole splitting energies of Ge-on-Si VS. A detailed comparison of PR spectral line shape fits and theoretical calculation led to the identification of various quantum-confined interband transitions. The temperature-dependent PR spectra of Ge/Si0.16Ge0.84MQW were analyzed using Varshni and Bose-Einstein expressions. The parameters that describe the temperature variations of various quantum-confined interband transition energies were evaluated and discussed.

Strain-Compensation in InAsP/GaInP Multiple Quantum Wells for 1.3 μm Wavelength

1995 ◽  
Vol 379 ◽  
Author(s):  
X. B. Mei ◽  
C.W. Tu
Keyword(s):  
Quantum Wells ◽  
Lattice Mismatch ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Narrow Line Width ◽  
Gas Source ◽  
Wide Range ◽  
Strain Compensation

ABSTRACTWe show that high-quality strain-compensated InAsxP1−x/GayIn1−yP multiple quantum wells (MQWs) can be grown by gas-source molecular beam epitaxy on InP substrates even though the InAsxP1−x quantum wells have a large lattice mismatch (∼ 1.3%) with respect to InP. Very sharp satellite peaks in double-crystal X-ray diffraction and narrow line width in low-temperature photoluminescence (FWHM of 4 meV at 9 K) are obtained from MQWs of up to 50 periods. Strain compensation allows a wide range of the net strain around the ideally compensated point, where the net strain equals zero, without degrading crystalline quality.

MBE Growth and Characterization of InSb/AlxIn1−xSb Strained Layer Structures

1996 ◽  
Vol 450 ◽  
Author(s):  
K. J. Goldammer ◽  
W. K. Liu ◽  
W. Ma ◽  
M. B. Santos ◽  
R. J. Hauenstein ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Mobility ◽  
Structural Quality ◽  
Electron Systems ◽  
X Ray Diffraction ◽  
Mbe Growth ◽  
Gaas Substrates ◽  
Layer Structures

ABSTRACTThree types of structures were fabricated using molecular beam epitaxy. High-resolution x-ray diffraction measurements demonstrated the high structural quality of InSb/AlxIn1−xSb superlattices grown on InSb and GaAs substrates. Hall effect data revealed the effect of substrate temperature on autocompensation in InSb δ-doped with Si. Two-dimensional electron systems with a high mobility were realized in InSb quantum wells with AlxIn1−xSb barriers δ-doped with Si.

Single Crystal Wurtzitic Aluminum Nitride Growth on Silicon Using Supersonic Gas Jets

1995 ◽  
Vol 395 ◽  
Author(s):  
S. A. Ustin ◽  
L. Lauhon ◽  
K. A. Brown ◽  
D. Q. Hu ◽  
W. Ho
Keyword(s):  
Aluminum Nitride ◽  
Growth Rates ◽  
High Energy ◽  
X Ray Diffraction ◽  
Rutherford Back Scattering ◽  
X Ray ◽  
Supersonic Molecular Beam ◽  
Supersonic Beams ◽  
Wide Range

ABSTRACTHighly oriented aluminum nitride (0001) films have been grown on Si(001) and Si (111) substrates at temperatures between 550° C and 775° C with dual supersonic molecular beam sources. Triethylaluminum (TEA;[(C2H5)3Al]) and ammonia (NH3) were used as precursors. Hydrogen, helium, and nitrogen were used as seeding gases for the precursors, providing a wide range of possible kinetic energies for the supersonic beams due to the disparate masses of the seed gases. Growth rates of AIN were found to depend strongly on the substrate orientation and the kinetic energy of the incident precursor; a significant increase in growth rate is seen when seeding in hydrogen or helium as opposed to nitrogen. Growth rates were 2–3 times greater on Si(001) than on Si(111). Structural characterization of the films was done by reflection high energy electron diffraction (RHEED) and x-ray diffraction (XRD). X-ray rocking curve (XRC) full-width half-maxima (FWHM) were seen as small as 2.5°. Rutherford back scattering (RBS) was used to determine the thickness of the films and their chemical composition. Films were shown to be nitrogen rich, deviating from perfect stoichiometry by 10%–20%. Surface analysis was performed by Auger electron spectroscopy (AES).

Epitaxial Growth and Characterization of Nonpolar A-Plane AlGaN-Based Multiple Quantum Wells

2018 ◽  
Vol 934 ◽  
pp. 8-12
Author(s):  
Jian Guo Zhao ◽  
Xiong Zhang ◽  
Jia Qi He ◽  
Shuai Chen ◽  
Zi Li Wu ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Chemical Vapor ◽  
Multiple Quantum Wells ◽  
Modulation Method ◽  
Duty Ratio ◽  
Organic Chemical ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Metal Organic

A serious of non-polar a-plane AlGaN-based multiple quantum wells (MQWs) were successfully grown on the semi-polar r-plane sapphire substrate with metal organic chemical vapor deposition technology. Intense MQWs-related emission peaks at an emission wavelength covered from 277-294 nm were observed based on the photoluminescence measurement. It was found that the employment of the trimethyl-aluminum (TMAl) flow duty-ratio modulation method which was developed based on the two-way pulsed-flows growth technique played a crucial role to control the Al composition of the non-polar a-plane AlGaN epi-layers. The non-polar a-plane AlGaN-based MQWs were deposited with the new developed TMAl flow duty-ratio modulation technique. Evident-3th order X-ray diffraction (XRD) satellite peak was observed from the high resolution-XRD measurement, proving the successful growth of non-polar a-plane AlGaN-based MQWs with abrupt hetero-interfaces.

scholarly journals Synthesis and Crystallographic Characterization of X-Substituted 2,4-Dinitrophenyl-4′-phenylbenzenesulfonates

Chemistry ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 591-599
Author(s):  
Brock A. Stenfors ◽  
Richard J. Staples ◽  
Shannon M. Biros ◽  
Felix N. Ngassa
Keyword(s):  
Diffraction Data ◽  
Pyridinium Salt ◽  
Environmentally Benign ◽  
Pyridinium Salts ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Aqueous Environments ◽  
Aqueous Base

Treatment of 2,4-dinitrophenol with sulfonyl chlorides in the presence of pyridine results in the formation of undesired pyridinium salts. In non-aqueous environments, the formation of the insoluble pyridinium salt greatly affects the formation of the desired product. A facile method of producing the desired sulfonate involves the use of an aqueous base with a water-miscible solvent. Herein, we present the optimization of methods for the formation of sulfonates and its application in the production of desired x-substituted 2,4-dinitrophenyl-4′-phenylbenzenesulfonates. This strategy is environmentally benign and supports a wide range of starting materials. Additionally, the intermolecular interactions of these sulfonate compounds were investigated using single-crystal x-ray diffraction data.

Photoreflectance Characterization of InGaAs Lattice Matched to InP

1993 ◽  
Vol 324 ◽  
Author(s):  
V. Bellani ◽  
M. Amiotti ◽  
M. Geddo ◽  
G. Guizzetti ◽  
G. Landgren
Keyword(s):  
Energy Gap ◽  
Lattice Mismatch ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Interfacial Strain ◽  
Valence Bands ◽  
Lattice Matched

AbstractWe measured photoreflectance (PR) spectra at different temperatures between 80 and 300 K, and optical absorption (OA) at 3 K on MOVPE grown Inl-xGaxAs nearly lattice-matched to InP. x-ray diffraction measurements gave a lattice mismatch δa/ao = -0.9.10−3 between ternary alloy and InP, corresponding to × = 0.485. We obtained the energy gap dependence on T from PR spectra. The blue shift of the gap was accounted for in terms of compositional difference with respect to the perfectly lattice matched alloy (× = 0.472), and elastic strain; moreover PR and OA showed evidence of the valence bands splitting at k = 0 due to interfacial strain, in fine agreement with theory.

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