Studies of Recombination Transfer in Alloys and Thin Quantum Wells of Ga0.47In0.53As/InP Using the Optically Detected Impact Ionisation Technique

1991 ◽  
Vol 240 ◽  
Author(s):  
P. OMLING
Keyword(s):  
Experimental Data ◽  
Quantum Well ◽  
Quantum Wells ◽  
Impact Ionisation ◽  
Optically Detected ◽  
Lattice Matched

ABSTRACTThe possibilities of the optically detected impact ionisation (ODII) technique are demonstrated. It is shown how the ODII technique can be used to extract detailed spectroscopie information in thick InGaAs layers where resolved peaks from free excitons, bound excitons, and free-to-acceptor recombinations are obtained. In an investigation of single- and multiple-monolayer quantum wells of lattice-matched GalnAs in InP the experimental data show how the transfer of impact ionised electrons from the InP layers to the different InGaAs quantum wells, where they recombine as free excitons, can be studied. The recombination in a thicker quantum well (18 monolayer) shows a more complicated behaviour, and an explanation based on defect-related recombination, including bound-exciton and free-to-bound recombinations, is suggested.

Quantum Well Shape Modification in Quaternary Quantum Wells

1991 ◽  
Vol 240 ◽  
Author(s):  
Emil S. Köteles ◽  
A. N. M. Masum Choudhury ◽  
A. Levy ◽  
B. Elman ◽  
P. Melman ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Optoelectronic Devices ◽  
Low Energy ◽  
Shape Modification ◽  
Simple Process ◽  
Thermally Driven ◽  
Inp Substrates ◽  
First Time ◽  
Lattice Matched

ABSTRACTQuantum well interdiffusion has been employed, for the First time in the quaternary InGaAsP/InP system (grown lattice matched to InP substrates), in order to modify the as-grown, nominally square, shapes of single quantum wells so as to increase their bandgap energies. This was accomplished, in a spatially selective manner, by using low energy ion implantation through a mask to generate vacancies. Subsequent rapid thermal annealing drove these vacancies down to the quantum wells where their presence enhanced the thermally driven interdiffusion of atoms between the well and barrier layers. The goal of this work is to develop a simple process for the integration of optoelectronic devices with differing functions.

scholarly journals Influence of phonon confinement on the optically detected electrophonon resonance linewidth in parabolic quantum wells

2017 ◽  
Vol 126 (1B) ◽  
Author(s):  
Nguyen Dinh Hien
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Optical Phonon ◽  
Large Range ◽  
Phonon Confinement ◽  
Resonance Linewidth ◽  
Numerical Result ◽  
Optically Detected ◽  
Parabolic Quantum Wells

We investigate the influence of optical phonon confinement described by Huang-Zhu (HZ) model on the optically detected electrophonon resonance (ODEPR) effect and ODEPR linewidth (ODEPRLW) in parabolic quantum wells (PQW) by using the operator projection. The obtained numerical result for the GaAs/AlAs parabolic quantum well shows that the ODEPR linewidths depend on the well's confinement frequency. Besides, in the two cases of confined and bulk phonons, the linewidth (LW) increases with the increase of confinement frequency. Furthermore, in the large range of the confinement frequency, the influence of phonon confinement plays an important role and cannot be neglected in considering the ODEPR linewidth.

X-ray Rocking Curve Analysis of Strained Heterointerfaces and Quantum Wells

1994 ◽  
Vol 38 ◽  
pp. 165-174
Author(s):  
C. R. Wie
Keyword(s):  
Experimental Data ◽  
Quantum Well ◽  
Quantum Wells ◽  
Quantum Effect ◽  
Multiple Quantum Well ◽  
Curve Analysis ◽  
Multiple Quantum ◽  
Rocking Curve ◽  
X Ray ◽  
Strained Quantum Wells

Abstract A detailed discussion is given for the x-ray rocking curve analysis of semiconductor heterointerfaces and strained quantum wells using x-ray interferometry. It is shown that for a single heteroepitaxiai layer sample and a multiple quantum well sample, the heterointerface where the composition changes in both anion and cation sublattices can be studied with a half monolayer sensitivity by analyzing the x-ray rocking curve profile. Such sample systems include GaInAs/InR InAs/GaSb, GalnP/GaAs, ZnSe/GaAs, etc. A simple kinematical diffraction principle involved in the x-ray analysis is explained. Namely, the relative phase difference between the reflection amplitudes of any two layers depends on the total sum of strain (or mismatch)-thickness products over the intervening layers and interfaces. The x-ray interferometry is also effective in measuring the strain-thickness product of strained quantum wells. Experimental data and analysis results are presented for a series of functional device structures having a strained quantum well. For a more complicated sampie structure which involves both a (strained) quantum-effect layer and strained interfaces, it is shown that the x-ray interferometry is only capable of providing the total strain-thickness product over the quantum layer and the surrounding interfaces, but no detailed information about the interface grading can be gained from the rocking curve analysis alone if onhy one isolated sample is measured. An experimental data of such a sample, 0.3μm-GaAs/100Å-GaInP/ GaAs(001), is analyzed.

scholarly journals XXIII Международный симпозиум Нанофизика и наноэлектроника", Нижний Новгород, 11-14 марта 2019 г. Гетероструктуры с GaAs/GaP-квантовыми ямами, выращенные на Si-подложках

2019 ◽  
Vol 53 (9) ◽  
pp. 1167
Author(s):  
Д.С. Абрамкин ◽  
М.О. Петрушков ◽  
М.А. Путято ◽  
Б.Р. Семягин ◽  
Е.А. Емельянов ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Temperature Stability ◽  
Nonradiative Recombination ◽  
High Concentration ◽  
Light Emitting ◽  
Highly Efficient ◽  
Hybrid Substrates ◽  
Recombination Centers ◽  
Lattice Matched

AbstractMolecular-beam epitaxy is used to produce GaP/Si hybrid substrates that allow the growth of highly efficient light-emitting heterostructures with GaAs/GaP quantum wells. Despite the relatively high concentration of nonradiative-recombination centers in GaP/Si layers, GaAs/GaP quantum-well heterostructures grown on GaP/Si hybrid substrates are highly competitive in terms of efficiency and temperature stability of luminescence to similar heterostructures grown on lattice-matched GaP substrates.

Strained Quantum Wells for P-channel InGaAs CMOS

2008 ◽  
Vol 1108 ◽  
Author(s):  
Padmaja Nagaiah ◽  
Vadim Tokranov ◽  
Michael Yakimov ◽  
Serge Oktyabrsky
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Room Temperature ◽  
Indium Content ◽  
Hole Transport ◽  
Scattering Mechanism ◽  
Almost All ◽  
20 Nm ◽  
Lattice Matched ◽  
Ingaas Quantum Well

AbstractWe present experimental results on the effect of strain on hole transport in InGaAs quantum well (QW) structures. Indium content was varied from lattice matched to high compressive stress in InGaAs/InP QW and the transport properties were analyzed at various temperatures (T = 77-300 K) using Hall measurements. The effect of QW thickness (4-20 nm) on hole transport is also presented. The current best results include room temperature mobility and sheet resistance of 390 cm2/V-s and 8500 Ω/sq., respectively. It was observed that the mobility had a T-1.8 dependence indicating similar scattering mechanism in almost all of the samples with prominent mechanism being due to interface and barrier scattering. Further optimization of p-channel for InGaAs CMOS needs to be performed using the above results as guidelines.

scholarly journals Influence of phonon confinement on the optically detected electrophonon resonance linewidth in parabolic quantum wells

2017 ◽  
Vol 126 (1B) ◽  
pp. 5
Author(s):  
Nguyen Dinh Hien
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Optical Phonon ◽  
Large Range ◽  
Phonon Confinement ◽  
Resonance Linewidth ◽  
Numerical Result ◽  
Optically Detected ◽  
Parabolic Quantum Wells

We investigate the influence of optical phonon confinement described by Huang-Zhu (HZ) model on the optically detected electrophonon resonance (ODEPR) effect and ODEPR linewidth (ODEPRLW) in parabolic quantum wells (PQW) by using the operator projection. The obtained numerical result for the GaAs/AlAs parabolic quantum well shows that the ODEPR linewidths depend on the well's confinement frequency. Besides, in the two cases of confined and bulk phonons, the linewidth (LW) increases with the increase of confinement frequency. Furthermore, in the large range of the confinement frequency, the influence of phonon confinement plays an important role and cannot be neglected in considering the ODEPR linewidth.

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.

Characterisation of multilayer materials using a position-sensitive atom probe

1990 ◽  
Vol 48 (4) ◽  
pp. 624-625
Author(s):  
RAD Mackenzie ◽  
G D W Smith ◽  
A. Cerezo ◽  
J A Liddle ◽  
CRM Grovenor ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Spatial Information ◽  
Chemical Vapour ◽  
Atom Probe ◽  
Organic Chemical ◽  
Growth Stages ◽  
Multiple Quantum ◽  
Quartz Wool ◽  
Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

scholarly journals Asymmetric Ge/SiGe coupled quantum well modulators

Nanophotonics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1765-1773
Author(s):  
Yi Zhang ◽  
Jianfeng Gao ◽  
Senbiao Qin ◽  
Ming Cheng ◽  
Kang Wang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Quantum Well ◽  
Quantum Wells ◽  
High Speed ◽  
Low Voltage ◽  
Extinction Ratio ◽  
High Frequency Response ◽  
Modulation Format ◽  
Silicon Photonic ◽  
Coupled Quantum Well

Abstract We design and demonstrate an asymmetric Ge/SiGe coupled quantum well (CQW) waveguide modulator for both intensity and phase modulation with a low bias voltage in silicon photonic integration. The asymmetric CQWs consisting of two quantum wells with different widths are employed as the active region to enhance the electro-optical characteristics of the device by controlling the coupling of the wave functions. The fabricated device can realize 5 dB extinction ratio at 1446 nm and 1.4 × 10−3 electrorefractive index variation at 1530 nm with the associated modulation efficiency V π L π of 0.055 V cm under 1 V reverse bias. The 3 dB bandwidth for high frequency response is 27 GHz under 1 V bias and the energy consumption per bit is less than 100 fJ/bit. The proposed device offers a pathway towards a low voltage, low energy consumption, high speed and compact modulator for silicon photonic integrated devices, as well as opens possibilities for achieving advanced modulation format in a more compact and simple frame.

Light Emission Properties of GaN-Based Double Heterostructures and Quantum Wells

1995 ◽  
Vol 395 ◽  
Author(s):  
D.A.S. Loeber ◽  
J.M. Redwing ◽  
N.G. Anderson ◽  
M.A. Tischler
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Stimulated Emission ◽  
Pump Light ◽  
Band Edge Emission ◽  
Emission Characteristics ◽  
Nitrogen Laser ◽  
Edge Emission ◽  
Edge Luminescence ◽  
Double Heterostructures

ABSTRACTEdge emission characteristics of optically pumped GaN-AlGaN double heterostructures and quantum wells are examined. The samples, which were grown by metalorganic vapor phase epitaxy, are photoexcited with light from a pulsed nitrogen laser. The pump light is focused to a narrow stripe on the sample surface, oriented perpendicular to a cleaved edge, and the edge luminescence is collected and analyzed. We first compare emission characteristics of highly excited GaN-AlGaN double heterostructures grown simultaneously on SiC and sapphire substrates. Polarization resolved spectral properties of edge luminescence from both structures is studied as a function of pump intensity and excitation stripe length. Characteristics indicative of stimulated emission are observed, particularly in the sample grown on SiC. We then present results demonstrating laser emission from a GaN-AlGaN separate-confinement quantum-well heterostructure. At high pump intensities, band edge emission from the quantum well exhibits five narrow (∼1 Å) modes which are evenly spaced by 10Å to within the resolution of the spectrometer. This represents the first demonstration of laser action in a GaN-based quantum-well structure.

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