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Showing 1 to 20 of 40 for “"buffer layers"”.
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Metal oxides as buffer layers in polycrystalline CdTe thin-film solar cells
… contact with the CdTe back surface. The use of a buffer layer behind the bare CdTe surface is found to be critical to the device performance. A thin 30-nm layer of Te have become the preferred choice of back buffer layer. Metal oxides like TeOx has been introduced as back buffer between the CdTe …
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Lattice-matched (In,Ga)P buffer layers for ZnSe based visible emitters
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.
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Investigation of CZTSe Solar Cell with ZnS, ZnSe and In2S3 as Buffer Layers
… replacement materials of predominantly used buffer layer CdS such as ZnS, ZnSe and In2S3 are investigated.
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Tradeoffs of the use of SiGe buffer layers in tandem GaAsP/Si solar cells
… routes, the use of a linearly graded SiGe buffer as interfacial layer between the two cells potentially yields the highest quality for the epitaxial GaAsP layer, an essential requirement for realization of high-efficiency solar cells. In this thesis, the impact of the SiGe buffer layer on …
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Numerical Analysis and Optimal Design of Efficient Thin-Film Solar Cells with Novel Buffer Layers
… and lowering the cost. Among other active layers inside the cell, performance enhancement depends on a layer that separate the light absorbing layers from the emitter. Ideally this intermediate layer, also known as buffer layer should be deposited with cost effective techniques, be …
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Microstructural Development and Superconducting Parameters of the YBa2Cu3O7-delta Coated Conductor
… flexible metallic substrate, using intermediate buffer layers to prevent chemical interaction. In order for the superconductor to be capable of carrying a high current density, its grains must have good crystallographic alignment in order to avoid the presence of high angle grain boundaries. This …
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Optical Investigations of Cd Free Cu<sub>2</sub>ZnSnS<sub>4</sub> Solar Cells
… In<sub>2</sub>S<sub>3</sub>, ZnS and ZnSe as buffer layers. The model is parameterized with the complex index of refraction of each layer in the stack. Using optical modeling, the quantum efficiency (QE) of the solar cell is calculated and used to calculate the maximum short circuit current. A …
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Perpendicular magnetic anisotropy in ion beam sputtered Co/Ni multilayers
Co/Ni multilayers display perpendicular magnetic anisotropy and have applications in magnetic devices that could lead to a large increase in the density of magnetic storage. Co/Ni 10-(2 Å Co/ 8Å Ni) and 10-(2 Å Co/ 4 Å Ni) multilayers were deposited with ion beam sputtering on either ion beam …
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Photoluminescence Measurement on Low-temperature Metal Modulation Epitaxy Grown GaN
… the PL signal from high temperature grown GaN buffer layers, and MME grown cap layers on top of the buffer layers, it was found that MME grown GaN cap has a significantly greater defect-related emission. The band edge PL from MME grown GaN found to be 3.51eV at low temperature. The binding …
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Monolithic heteroepitaxial integration of III-V semiconductor lasers on Si substrates
… components are fabricated. Graded Ge/GeSi buffer layers grown on standard Si substrates have been shown to produce near-lattice matched virtual substrates for GaAs integration on Si. This study investigated the crystal growth conditions and device fabrication techniques necessary for …
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Electronic transport and structure of a surface quantum well
… In this work, a structural study of antimonide buffer layers on GaAs substrates was performed. Using in situ diffraction and ex situ microscopy, we examine the lattice transition between GaAs substrates, and the highly mismatched material GaSb. When GaSb grows on GaAs, it follows a complex …
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Phosphorus Incorporation During Silicon(001):phosphorus Gas-Source Molecular Beam Epitaxy: Effects on Film Growth Kinetics, Surface Morphology, and the Self-Organization of Germanium Quantum Dot Overlays
… on three types of starting surfaces: (1) Si(001) buffer layers which serve as a reference, (2) Si(001) layers with predeposited P coverages thetaP ranging from 0 to 1 ML, and (3) P-doped Si(001) with CP = 3.4x1018-8.3x10 18 cm-3, which corresponds to thetaP = 0.5-0.8 ML. Predeposited P passivates …
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A market analysis for high efficiency multi-junction solar cells grown on SiGe
… solar cells built on compositionally graded SiGe buffer layers currently being developed by professors Steven Ringell of Ohio State University and Eugene Fitzgerald of MIT. Potential markets are similar to those currently occupied by high efficiency multi-junction space solar cells grown on a …
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High Quality ZnO Epitaxial Grown By Plasma Assisted Molecular Beam Epitaxy
… and characterization of high quality ZnO epitaxy layers.Zinc oxide (ZnO) epitaxy layers were grown on sapphire and epi-GaN substrates respectively, using plasma assisted molecular beam epitaxy (MBE) . Various growth conditions, such as growth temperature, II/VI ratio, and buffer layers, were …
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Dislocation engineering in InAlGaAs/SiGe alloy systems for heteroepitaxial integration
… that are created in the process and require buffer layers to accommodate such defects and minimize their impact on device performance. One buffer layer scheme that is receiving widespread adoption involves the direct growth of Ge on Si. It produces a threading dislocation density ~2x10⁷ cm⁻² …
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Epitaxial Nd-Fe-B films: Growth, texture, magnetism and the influence of mechanical elongation
… crystal MgO (001) substrates with different buffer layers in order to obtain good textures with different surface morphology. The smooth and continuous epitaxial films were suitable for performing magnetization measurements under stress. Although the magnetostriction is easily neglected in …
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Effects of ion processing and substrate variables on electrical characteristics of GaAs
… are compared. The DLTS response of active layers on Cr-doped GaAs is significantly different from those on undoped GaAs. A viable explanation that accounts for this difference is presented. The effects of furnace annealing on electrical properties of 50 keV, 4 x 10¹³ cm⁻² Si-implanted GaAs …
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Growth and magnetoelastic behavior of b-axis-oriented dysprosium
… Dy have been prepared between YxLu1-x alloy buffer layers, so that strain can be tuned from compressive (x=O) to tensile (x=l) and chosen values in between. The magnetic ordering temperatures, critical fields, and magnetization behavior vary systematically with strain. This behavior is …
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Desarrollo de sustratos de carburo de silicio mediante carburización e implantación iónica de silicio monocristalino
… for using them as templates, compliant, seed or buffer layers in SiC or III-N overgrowth by epitaxial growth techniques. These approaches let the consecution of a crystalline quality enough to the development of devices. Indeed, their use allow a significant reduction of the high defect density …
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Brillouin scattering from single-crystal dysprosium and gadolinium films
… on sapphire substrates with Nb (or Ta) and Y buffer layers. The room temperature data compared very well with the dispersion of acoustic phonon velocities calculated using the bulk elastic constants in the elastic model. We observed modest anomalies in the temperature dependences for the …
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