Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 18 of 18 for “"carrier confinement"”.
-
Optical and minority carrier confinement in lead selenide homojunction lasers.
Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.
-
Exploring and exploiting charge-carrier confinement in semiconductor nanostructures : heterodimensionality in sub-monolayer InAs in GaAs and photoelectrolysis using type-II heterojunctions
… and important technologies. Firstly, charge-carrier confinement in stacked sub-monolayer (SML) InAs in GaAs: SML deposition results in the formation of In-rich agglomerations within a lateral InGaAs quantum well (QW) with lower In content. Low-temperature photoluminescence (PL) and magneto-PL …
-
Fabrication and Characterization of Narrow-Stripe Quantum Well Laser Diodes
… techniques, designed to restrict current, carrier, and/or photon flow through the lasing cavity. This work aims to evaluate a non-conventional stripe laser processing technique which has the potential for effective current and possibly carrier confinement at low cost. This technique, …
-
LOW-TEMPERATURE CHARACTERIZATION OF A 1.55-μm MULTIPLE-QUANTUM-WELL LASER DOWN TO 10 K
… semiconductor laser with a multiple-quantum-well carrier confinement structure was characterized from room temperature down to 10 K. The temperature dependence of important laser parameters, such as threshold current, differential efficiency, emission wavelength, and series resistance, extracted …
-
Si-based Germanium-Tin (GeSn) Emitters for Short-Wave Infrared Optoelectronics
… was scrutinized from 10 to 300 K and the carrier confinement was analyzed through band offset calculations in the QW structure. Moreover, the electrical and optical characteristics of n-i-p Ge/Ge0.92Sn0.08/Ge light emitting diodes (LEDs) with surface emitting and edge emitting …
-
3D Electro-thermal Monte Carlo Study of Transport in confined Silicon Devices
… essential. To better capture the influence of carrier confinement, the electrostatically quantum-corrected full-band MC model has the added feature of being able to incorporate subband scattering. The scattering rate selection introduces quantum correction into carrier movement.
-
Lattice Engineering of III-Nitride Heterostructures and Their Applications
… and the composition modulation has impacts on carrier recombination dynamics. We also showed that the controlled relaxation of a very thin AlN buffer (20 ~ 30 nm) or a graded composition InGaN buffer can significantly reduce the defect density of a subsequent epitaxial layer. Finally, we …
-
Development of Compound Semiconductor FET and Integrated Low -Voltage RF MEMS Switch Technology for Reconfigurable MMIC Applications
… here features a binary barrier layer to improve carrier confinement and increase current density. A metal-contact RF MEMS shunt switch has been developed as a low-loss, wide bandwidth passive component, and recent work has focused on achieving good reliability with low actuation voltages. A brief …
-
III-V inverse quantum dots fabrication, characterization and application
The quantum dot offers carrier confinement in three dimensions. It is expected to improve performance of photonic devices. However, quantum dot fabrication still requires significant quality improvement such as high uniformity and location controllability to be commercialized. In this thesis, the …
-
Phonon Spectroscopy and Low-Dimensional Electron Systems
… polarization vector, and the sensitivity to the confinement parameters of the low-dimensional electron systems. We show that screening of the electron-phonon interaction can have a much stronger influence on the results of angle-resolved phonon spectroscopy than expected from transport …
-
Design and Analysis of Whispering Gallery Mode Semiconductor Lasers
… diffraction and scattering losses, current and carrier confinement, and surface recombination on electrical/optical device characteristics. In addition, a methodology has been developed for separating out process optimization work from the task of identifying the best means for directional light …
-
Fabrication and Device Applications of Self Assembled Nanostructures
… confined in 1–2-nm-sized cavities. Because carriers in organic molecules are localized over individual molecules or atoms but the phonons are delocalized, we believe that this feature is caused by a phonon bottleneck effect. Organic fluorophore molecules, electrosprayed within nanometer …
-
Quantum wells on indium gallium arsenic compositionally graded buffers realized by molecular beam epitaxy
… the aluminum-containing barriers necessary for carrier confinement. Furthermore, upon proper ex-situ annealing, it was able to obtain QW emission as strong as, sometimes even stronger than, that from QWs pseudomorphically grown on GaAs.However, when even slight tensile or compressive strain was …
-
The Role of Quantum Dot Size on the Performance of Intermediate Band Solar Cells
… change in the position of the band edge, due to carrier confinement, consistent with a QD size variation as verified by TEM and PL. Measurements demonstrate that the EQE in the NIR range of the spectrum is enhanced in the QD IBSCs devices due to light absorption by the QDs. This work also …
-
Theory and simulation of quantum nanostructures for integrated photonics
… QW, but can in a QD due to the three-dimensional carrier confinement. We undertake theoretical analysis of the lateral-field QCSE in 1.3 μm InGaAs/GaAs QDs. Comparing the QCSE produced by vertical and lateral electric fields for realistic QD morphology a robust lateral field QCSE is demonstrated, …
-
Predictive simulation and design of III-V heterostructures for light emission and detection
… presence of spatially indirect (type-II-like) carrier confinement, are close to that of bulk InAs and compare favourably to those calculated for mid-IR type-I pseudomorphic and metamorphic quantum well structures having comparable emission wavelengths. Our analysis explicitly quantifies the …
-
Semiconductor quantum dots for mid-IR light emission
… QD grown by MBE. We demonstrate strong carrier confinement in, and electroluminescence (EL) from, quantum nanostructures fabricated from epitaxially grown quan- tum wells (QWs) using a top-down nanosphere lithography (NSL), dry-etch, mass-transport, and overgrowth fabrication process. …
-
Desarrollo de dispositivos optoelectrónicos mediante crecimiento por MBE y caracterización de nanoestructuras de punto cuántico basadas en (Ga,In)(As,N)
… show as consequence of their three-dimensional carrier confinement. The material system based on (Ga,In)(As,N) QDs on GaAs substrates offers, on one hand the attractive possibility of developing innovative optoelectronic devices by means of the introduction of nitrogen into their structure; and …