Nondestructive Characterization of ZnSe/GaAs Heterostructure Using Transverse Acoustoelectric Voltage Spectroscopy

1992 ◽  
Vol 261 ◽  
Author(s):  
K. J. Han ◽  
A. Abbate ◽  
I. B. Bhat ◽  
S. Akram ◽  
P. Das
Keyword(s):  
Gaas Substrate ◽  
Energy Levels ◽  
Surface Recombination ◽  
High Resistivity ◽  
Misfit Dislocations ◽  
Trap States ◽  
Electrical And Optical Properties ◽  
Relative Change ◽  
Nondestructive Characterization

ABSTRACTThe electrical and optical properties of the heterostructure interface between high resistivity ZnSe and the semi-insulating GaAs substrate have been investigated using Transverse Acoustoelectric Voltage (TAV) spectroscopy. From the TAV spectra and the relative change of the TAV amplitude (ΔTAV/TAV), we have found the carrier type and concentration of ZnSe as well as the energy levels of various trap states at the heterostructure interface. The spectral behavior of the ΔTAV/TAV curves varied for samples of different ZnSe epilayer thickness. From the measurements, the surface recombination velocities (SRV's) were calculated. For the pseudomorphic ZnSe films on GaAs, a reduction in the SRV's was measured. As the thickness of the ZnSe film was increased, the various ΔTAV/TAV indicated presence of a large number of interface states due to the introduction of misfit dislocations.

scholarly journals InAs/GaSb Superlattice Based Mid-Infrared Interband Cascade Photodetectors Grown on Both Native GaSb and Lattice-Mismatched GaAs Substrates

Proceedings ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 38
Author(s):  
Hackiewicz ◽  
Kopytko ◽  
Rutkowski ◽  
Martyniuk ◽  
Ciura
Keyword(s):  
Gaas Substrate ◽  
Room Temperature ◽  
Device Performance ◽  
Misfit Dislocations ◽  
Type Ii ◽  
Electrical And Optical Properties ◽  
Mid Infrared ◽  
Type Ii Superlattice ◽  
Gaas Substrates ◽  
Optical Immersion

Electrical and optical properties of interband cascade infrared photodetectors with InAs/GaSb type-II superlattice absorbers are investigated in this work. We compare the detection parameters of detectors grown on the native GaSb substrate and lattice-mismatched GaAs substrate and seek solutions to enhance device performance, specifically with using an optical immersion. The detectors grown on GaAs have better detection parameters at room temperature, but at lower temperatures the misfit dislocations become more important and detectors grown on GaSb become better.

Structural properties of GaAs/InGaAs/GaAs (001) and InGaAs/GaAs (001) heterostructures and correlation with electronic properties

1990 ◽  
Vol 48 (4) ◽  
pp. 602-603
Author(s):  
J.M. Bonar ◽  
R. Hull ◽  
R. Malik ◽  
R. Ryan ◽  
J.F. Walker
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Gaas Substrate ◽  
Critical Thickness ◽  
Lattice Mismatch ◽  
Band Offset ◽  
Misfit Dislocations ◽  
Gaas Substrates ◽  
Gaas Structure ◽  
Low X

In this study we have examined a series of strained heteropeitaxial GaAs/InGaAs/GaAs and InGaAs/GaAs structures, both on (001) GaAs substrates. These heterostructures are potentially very interesting from a device standpoint because of improved band gap properties (InAs has a much smaller band gap than GaAs so there is a large band offset at the InGaAs/GaAs interface), and because of the much higher mobility of InAs. However, there is a 7.2% lattice mismatch between InAs and GaAs, so an InxGa1-xAs layer in a GaAs structure with even relatively low x will have a large amount of strain, and misfit dislocations are expected to form above some critical thickness. We attempt here to correlate the effect of misfit dislocations on the electronic properties of this material.The samples we examined consisted of 200Å InxGa1-xAs layered in a hetero-junction bipolar transistor (HBT) structure (InxGa1-xAs on top of a (001) GaAs buffer, followed by more GaAs, then a layer of AlGaAs and a GaAs cap), and a series consisting of a 200Å layer of InxGa1-xAs on a (001) GaAs substrate.

A Possible Basis for Nondestructive Characterization of Ropes of Nylon 6

1997 ◽  
Vol 503 ◽  
Author(s):  
H. Jiang ◽  
M. K. Davis ◽  
R. K. Eby ◽  
P. Arsenovic
Keyword(s):  
Tensile Strength ◽  
Service Life ◽  
Fiber Diameter ◽  
Structural Parameters ◽  
Crystal Form ◽  
Nylon 6 ◽  
Remaining Service Life ◽  
Nondestructive Characterization ◽  
Fractional Content

ABSTRACTPhysical properties and structural parameters have been measured for ropes of nylon 6 as a function of the number of use operations. The fractional content of the α crystal form, sound velocity, birefringence, tensile strength and length all increase systematically and significantly with increasing the number of use operations. The fractional content of the γ crystal form and fiber diameter decrease with use. These trends indicate that the measurement of such properties and structural parameters, especially the length, provide a possible basis for establishing a reliable, rapid, and convenient nondestructive characterization method to predict the remaining service life of nylon 6 ropes.

scholarly journals A New Piano-Stool Ruthenium(II) P-Cymene-Based Complex: Crystallographic, Hirshfeld Surface, DFT, and Luminescent Studies

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Mohd. Muddassir ◽  
Abdullah Alarifi ◽  
Mohd. Afzal
Keyword(s):  
Density Functional ◽  
Weak Interactions ◽  
Energy Levels ◽  
Hirshfeld Surface ◽  
Binding Energies ◽  
Orbital Energy ◽  
Aminosalicylic Acid ◽  
Full Characterization

A new complex (Ru(η6-p-cymene)(5-ASA)Cl2) (1) where 5-ASA is 5-aminosalicylic acid has been prepared by reacting the ruthenium arene precursors ((η6-arene)Ru(μ-Cl)Cl)2, with the 5-ASA ligands in a 1:1 ratio. Full characterization of complex 1 was accomplished by elemental analysis, IR, and TGA following the structure obtained from a single-crystal X-ray pattern. The structural analysis revealed that complex 1 shows a “piano-stool” geometry with Ru-C (2.160(5)- 2.208(5)Å), Ru-N (2.159(4) Å) distances, which is similar to equivalents sister complex. Density functional theory (DFT) was used to calculate the significant molecular orbital energy levels, binding energies, bond angles, bond lengths, and spectral data (FTIR, NMR, and UV–VIS) of complex 1, consistent with the experimental results. The IR and UV–VIS spectra of complex 1 were computed using all of the methods and choose the most appropriate way to discuss. Hirshfeld surface analysis was also executed to understand the role of weak interactions such as H⋯H, C⋯H, C-H⋯π, and vdW interactions, which play a significant role in the crystal environment’s stability. Moreover, the luminescence results at room temperature show that complex 1 gives a more intense emission band positioned at 465 nm upon excitation at 330 nm makes it a suitable candidate for the building of photoluminescent material.

Sign in / Sign up

Export Citation Format

Share Document