Characterization of Undoped Pseudomorphic InGaAs/GaAs Quantum Wells by Electron Beam Electroreflectance (EBER) and Photoluminescence (PL)

1989 ◽  
Vol 160 ◽  
Author(s):  
M. H. Herman ◽  
A. Dodabalafur ◽  
I. D. Ward ◽  
B. G. Streetman
Keyword(s):  
Electron Beam ◽  
Quantum Wells ◽  
Heavy Hole ◽  
Interband Transitions ◽  
Conduction Band Offset ◽  
Quantum Transitions ◽  
Heavy Hole Subband ◽  
Rectangular Barrier ◽  
Barrier Model

AbstractWe have investigated the interband optical transitions within undoped pseudomorphic InyGa1-yAs/GaAs quantum wells of a range of thickness from 50Å to 150Å, and y values 0.1 to 0.2. From photoluminescence (PL), we identify the lowest interband transitions. Electron beam electroreflectance (EBER) modulation spectroscopy is utilized to detect the lowest and the higher energy interband transitions within the quantum wells. We compare the measured interband energies to those calculated theoretically.We have observed exciton-like transitions attributable to the heavy hole and light hole levels and most importantly, confined states of the split-off valence band, not reported to date. The multiplicity of observed quantum transitions allows rectangular barrier model parametrization of these wells, using hypothetical strain splitting of the various subbands. For five such quantum wells, we find the estimated indium contents and well widths to be nearly nominal, with consistent values between independent 300K and 100K data. With respect to the heavy hole subband, the conduction band offset Qc is estimated to be 0.586 ±0.024. With suitable values, all of the transitions, including those of the splitoff band, are predicted accurately.

Photoreflectance characterization of interband transitions in GaAs/AlGaAs multiple quantum wells and modulation‐doped heterojunctions

1985 ◽  
Vol 46 (10) ◽  
pp. 970-972 ◽  
Author(s):  
O. J. Glembocki ◽  
B. V. Shanabrook ◽  
N. Bottka ◽  
W. T. Beard ◽  
J. Comas
Keyword(s):  
Quantum Wells ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Interband Transitions

Characterization of III-V Semiconductor Structures Using Electron Beam Electroreflectance (EBER) spectroscopy.

1988 ◽  
Vol 144 ◽  
Author(s):  
M. H. Herman ◽  
I. D. Ward ◽  
S. E. Buttrill ◽  
G. L. Francke
Keyword(s):  
Electron Beam ◽  
Quantum Well ◽  
Quantum Wells ◽  
Sample Surface ◽  
Band Gap Energy ◽  
Quantum Well Structures ◽  
Resonant States

ABSTRACTEBER is a form of modulated reflectance spectroscopy in which a low energy electron beam alters the sample surface potential. For III-V semiconductors, the spectra are characteristic of electroreflectance, including excitonic, interband, and impurity transitions. The study of these transitions provides accurate estimations of band gaps in bulk and thick film samples. Measurements of the band gap energy in compounds such as AlxGa1-xAs provide highly precise evaluations of their composition.Additionally, EBER spectra of quantum well structures and heterojunctions provide useful information about the composition and quality of materials and interfaces. For quantum wells, detected features suggest the presence of allowed, disallowed, and resonant states. In EBER spectra of HEMT structures, peaks are apparent resulting from transitions between the valence band and the states in which the electrons are confined. We present examples of EBER determination of AlGaAs composition, single GaAs/AlGaAs quantum well evaluation, and HEMT characterization.

Growth and Characterization of AlGaN Multiple Quantum Wells for Electron-Beam Target for Deep-Ultraviolet Light Sources

2013 ◽  
Vol 52 (1S) ◽  
pp. 01AF03 ◽  
Author(s):  
Fumitsugu Fukuyo ◽  
Shunsuke Ochiai ◽  
Hideto Miyake ◽  
Kazumasa Hiramatsu ◽  
Harumasa Yoshida ◽  
...  
Keyword(s):  
Electron Beam ◽  
Quantum Wells ◽  
Ultraviolet Light ◽  
Multiple Quantum Wells ◽  
Light Sources ◽  
Multiple Quantum ◽  
Deep Ultraviolet

A very rapid in situ Kikuchi technique to determine relative crystal misorientation

1988 ◽  
Vol 46 ◽  
pp. 830-831
Author(s):  
J. I. Bennetch
Keyword(s):  
Electron Beam ◽  
Analytical Techniques ◽  
Superplastic Forming ◽  
The Other ◽  
Kikuchi Pattern ◽  
Kikuchi Line ◽  
Line Analysis

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.

Characterization of GaAs/AlGaAs quantum wells and quantum wires by chemical lattice imaging

1994 ◽  
Vol 52 ◽  
pp. 736-737
Author(s):  
A. Carlsson ◽  
J.-O. Malm ◽  
A. Gustafsson
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Quantum Wires ◽  
Vapour Phase ◽  
Quantitative Information ◽  
Lattice Imaging ◽  
Vapour Phase Epitaxy ◽  
Metalorganic Vapour Phase Epitaxy ◽  
High Resolution Images

In this study a quantum well/quantum wire (QW/QWR) structure grown on a grating of V-grooves has been characterized by a technique related to chemical lattice imaging. This technique makes it possible to extract quantitative information from high resolution images.The QW/QWR structure was grown on a GaAs substrate patterned with a grating of V-grooves. The growth rate was approximately three monolayers per second without growth interruption at the interfaces. On this substrate a barrier of nominally Al0.35 Ga0.65 As was deposited to a thickness of approximately 300 nm using metalorganic vapour phase epitaxy . On top of the Al0.35Ga0.65As barrier a 3.5 nm GaAs quantum well was deposited and to conclude the structure an additional approximate 300 nm Al0.35Ga0.65 As was deposited. The GaAs QW deposited in this manner turns out to be significantly thicker at the bottom of the grooves giving a QWR running along the grooves. During the growth of the barriers an approximately 30 nm wide Ga-rich region is formed at the bottom of the grooves giving a Ga-rich stripe extending from the bottom of each groove to the surface.

Atomic scale characterization of GaInN/GaN multiple quantum wells in V-shaped pits

2011 ◽  
Vol 98 (18) ◽  
pp. 181904 ◽  
Author(s):  
Shigetaka Tomiya ◽  
Yuya Kanitani ◽  
Shinji Tanaka ◽  
Tadakatsu Ohkubo ◽  
Kazuhiro Hono
Keyword(s):  
Quantum Wells ◽  
Atomic Scale ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Scale Characterization

Characterization of AA7075/AA5356 gradient transition zone in an electron beam wire-feed additive manufactured sample

2021 ◽  
Vol 172 ◽  
pp. 110867
Author(s):  
V. Utyaganova ◽  
A. Filippov ◽  
S. Tarasov ◽  
N. Shamarin ◽  
D. Gurianov ◽  
...  
Keyword(s):  
Electron Beam ◽  
Transition Zone ◽  
Feed Additive ◽  
Wire Feed

scholarly journals Valence Band Mixing in GaAs/AlGaAs Quantum Wells Adjacent to Self-Assembled InAlAs Antidots

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Takuya Kawazu
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Valence Band ◽  
Energy Barrier ◽  
Heavy Hole ◽  
Electronic States ◽  
Light Hole ◽  
Photoluminescence Excitation ◽  
Band Mixing ◽  
Valence Band Mixing

Optical properties of GaAs/AlGaAs quantum wells (QWs) in the vicinity of InAlAs quantum dots (QDs) were studied and compared with a theoretical model to clarify how the QD strain affects the electronic states in the nearby QW. In0.4Al0.6As QDs are embedded at the top of the QWs; the QD layer acts as a source of strain as well as an energy barrier. Photoluminescence excitation (PLE) measurements showed that the QD formation leads to the increase in the ratio Ie-lh/Ie-hh of the PLE intensities for the light hole (lh) and the heavy hole (hh), indicating the presence of the valence band mixing. We also theoretically calculated the hh-lh mixing in the QW due to the nearby QD strain and evaluated the PLE ratio Ie-lh/Ie-hh.

Optical characterization of type-II ZnO/ZnS multiple quantum wells grown by atomic layer deposition

2020 ◽  
Vol 694 ◽  
pp. 137740 ◽  
Author(s):  
Mostafa Afifi Hassan ◽  
Aadil Waseem ◽  
Muhammad Ali Johar ◽  
Sou Young Yu ◽  
June Key Lee ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Quantum Wells ◽  
Atomic Layer ◽  
Optical Characterization ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Type Ii ◽  
Layer Deposition
Sign in / Sign up

Export Citation Format

Share Document