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.
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Showing 1 to 20 of 218 for “"Photodetectors"”.
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Integrated Heteroepitaxial Photodetectors
… high performance. In this work, Ge-on-Si p-i-n photodetectors illuminated under normal incidence have demonstrated comparable responsivity and dark current density to devices processed at high temperatures. Relatively low temperature anneals (500°C) increased performance, but as-grown diodes …
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Ge photodetectors for Si microphotonics
… the integration of pure Ge near-infrared photodetectors on Si. Ge epilayers were grown directly on Si by a two-step ultra-high-vacuum/chemical-vapor-deposition (UHV/CVD) process. This work conclusively proves that threading-dislocation densities in the Ge epilayers, measured both by …
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Engineered quantum dots for infrared photodetectors
Quantum Dot Infrared Photodetector (QDIP) Focal Plane Arrays (FPAs) have been proposed as an alternative technology for the 3rd generation FPAs. QDIPs are emerging as a competitive technology for infrared detection and imaging especially in the midwave infrared (MWIR) and longwave infrared (LWIR) …
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Fabrication and characterization of avalanche photodetectors
Avalanche photodetectors are important for imaging applications because of their high sensitivity and low noise levels. For imaging applications, however, a two-dimensional array of APDs is required, and there are many fabrication issues involved in making such an array over a large area. In this …
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Photodetectors for graphene-based integrated photonics
… First, I show plasmonic enhanced graphene photodetectors (GPDs) on silicon nitride waveguides, which generate a voltage from optically generated hot-carrier distributions in SLG via the photo-thermoelectric (PTE) effect. Then, I demonstrate PTE-GPDs—fabricated from layered material …
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Design of quantum well infrared photodetectors
QWIPs which respond to normally incident radiation without the need for an optical grating are of particular interest because they can be fabricated with fewer process steps and increased expected yield. An important contribution of this work is the demonstration of the first n-type QWIP (n-QWIP) …
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Photodetectors based on colloidal quantum dots
… we set out to develop thin-film, layered photodetectors in which the active layer is a chemically annealed QD solid. This thesis reports initial steps in this development. Chapters 1 and 2 contain introductory material. In Chapter 3, we demonstrate a layered QD photodetector (QD-PD) in …
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Strain-engineered CMOS-compatible Ge photodetectors
The development of CMOS-compatible photodetectors capable of operating throughout the entire telecommunications wavelength spectrum will aid in the integration of photodetectors with Si microelectronics, thus offering a low cost platform for high performance photoreceivers. This thesis demonstrates …
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Synthesis of CsPbBr3 Quantum Dots for Photodetectors
… conjugate polymer to fabricate nanocomposite photodetectors. We found that the size and optical properties of CsPbBr3 QDs are affected by varying the amount of precursor injected into antisolvent, ligands in precursor or antisolvent, and centrifugation speed. Besides, we have fabricated the …
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Novel structures for lattice-mismatched infrared photodetectors
… of nBn detector structures as lattice mismatched photodetectors. Using a design based on an InAsSb bulk-material absorber, a comparison was again drawn between two samples, one grown on mismatched GaAs and a second grown on native GaSb. This time, device dark current densities were found to be …
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Investigation of silicon-cadmium sulphide heterojunction photodetectors
Abstract available p. 4
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Indium-Gallium-Arsenide Quantum Wire Infrared Photodetectors
… 0.24As quantum wire infrared photodetectors (QRIPs) grown on semi-insulating (001) on-axis InP substrates via solid-source molecular beam epitaxy (MBE) have been fabricated and characterized. The quantum wires (QWRs) were formed using an in situ on-step strain-induced …
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Resonant Cavity Enhanced Photodetectors and Optoelectronic Switches
Described in this thesis is an investigation of novel structures consisting of optoelectronic devices integrated into Fabry-Perot resonant cavities. The photosensitivity of conventional detectors is governed by the optical properties of the semiconductor material requiring thick absorption regions …
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Material processing of quantum well infrared photodetectors
… multiple quantum well (MQW) infrared (IR) photodetectors (QWIPs) epitaxially grown on GaAs and Si substrates is presented. The advances in epitaxial growth allow the precise control of the dimensions, doping, and matrix concentration of the MQW. Therefore, the design of a QWIP with …
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Demonstrating visibly transparent solar cells and photodetectors
… devices, such as silicon solar cells and photodetectors, is despite significant research still expensive and energy intensive. Especially for solar cells, high upfront costs are a limiting factor for large-scale fabrication and implementation. Organic semiconductors have attracted …
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Nanostructures for Coherent Light Sources and Photodetectors
… lack of efficient light sources and broadband photodetectors, which could be integrated with the silicon complementary metal-oxide-semiconductor (CMOS) technology. Persistent efforts continue to achieve efficient light emission as well as broadband photodetection from silicon in extending the …
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Surface plasmons for enhanced metal-semiconductor-metal photodetectors
… circuits, optical filters and SPP enhanced photodetectors. In the past decade, there have been several experimental and theoretical research and development activities which reported on the extraordinary optical transmission through subwavelength metallic apertures as well as through …
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Study of quantum dot and quantum well photodetectors
A study of quantum dots-in-well infrared photodetectors (QDIPs) yields results useful for the creation of a two-colour QDIP. Quantum dot infrared photodetectors (QDIPs) have been shown to be a key technology in mid and long wavelength infrared detection due to their potential for normal incidence …
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Plasmonics for On-Chip Photodetectors and Light Sources
<p>Quantum emitters and thermal photodetectors serve as key building blocks for future quantum information and sensing systems. Their properties can be significantly enhanced by integrating them with nanostructured elements, tailoring their interactions with incident optical fields. Quantum …
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