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 18 of 18 for “"UV LEDs"”.
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Torsion Pendulum Testing of the LISA Charge Management System
… were mercury-vapor lamps emitting photons in the UV range. In this thesis, we will present our on-ground testing campaign of a prototype Charge Management System for LISA, which relies on UV-LEDs as light sources. LEDs, compared to mercury-vapor lamps, can emit short pulses of UV light (~10 ns), …
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Preparation and characterization of AlGaN structures for UVA LEDs
Visible / UV LEDs are developed from the same III-Nitride compounds semiconductor materials and share many design and technological aspects. However, the efficiency difference between the two types is quite significant, where the latter lags. Recent advancements in material technology such as the …
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HIGH POWER ALGAN BASED DEEP UV LED LAMPS: DESIGN, FABRICATION AND CHARACTERIZATION
… and emerging medical instrumentation. Current UV-LEDs are limited in the market penetration due to the relatively low output power and quantum efficiency despite their inherent benefits of low cost, small size, and low power consumption.</p>
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Structural and Morphological Analyses of Aln and Algan Layers
<p>III-nitride semiconductors based Deep UV LEDs are the prospective candidates to replace the traditional UV sources, such as mercury vapor lamps, used in the applications of water and air purification, germicidal and biomedical instrumentation systems and others. Due to the lack of native …
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Analysis of Light Extraction Efficiency Enhancement for Deep Ultraviolet and Visible Light-Emitting Diodes with III-Nitride Micro-Domes
… of lighting technology such as ultraviolet (UV) / visible light-emitting diodes and laser diodes. The limitation occurred in light extraction efficiency of III-nitride LEDs is attributed to the large refractive index difference between III-nitride semiconductor and free space, which leads to …
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Ultravioletinės srities šviesos diodų žemadažnio triukšmo tyrimas /
… low-frequency noise characteristics of UV LEDs, evaluate simultaneous cross-correlation coefficient between electrical and optical fluctuations and apply correlation method for InGaN-based LEDs. Two AlGaN-based LEDs (275 nm) and two InGaN-based LEDs (370 and 385 nm) were investigated. …
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MOVPE growth and characterization of Al(Ga)N and InAlN/AlGaN quantum wells for UV LED applications
… in the production light emitting diodes (LEDs) and laser diodes (LDs) over the past two decades. Last year, the Nobel Prize in Physics was awarded jointly to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for inventing a new energy efficient and environmental friendly light source: blue …
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Packaging designs for ultraviolet light emitting diodes
… / Gallium Nitride (GaN) based deep ultraviolet (DUV) light emitting didoes (LEDs) with emission wavelengths between 200-280 nm enable key emerging technologies such as water/air purification and sterilization, covert communications and portable bio-agent detection/identification systems for …
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Mechanical design of optics bench for UV-LED based liquid chromatography detector
… that uses Ultraviolet Light Emitting Diodes (UV-LEDs) as the light source as opposed to currently used deuterium lamps required new design of the mechanical and structural components associated with it. The optics bench assembly is the heart of the detector system on which the detector optical …
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Quantifying the stimuli of photorheological fluids
… for use in combination with commercial UV LEDs if the speed of transition is a constraint. However, we suggest features of a fluid ideal for this application and illustrate how techniques such as decreasing film thickness are effective in accelerating the reaction only for fluids with …
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The development of steady State and lifetime fluorescence instruments for real time in situ aquatic chemistry measurements
… (called LEDIF) employs a novel flowcell, 6 UV LEDs as excitation sources, a wideband lamp, and a spectrometer to measure steady state chemical fluorescence and absorbance. The instrument is packaged aboard an autonomous underwater vehicle (AUV) and demonstrates the ability to map chemical …
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Aluminium nitride (AlN) as buffer layer for deposition of gallium nitride (GaN) thin films on silicon substrates using magnetron sputtering technique
… of GaN-based ultraviolet light-emitting diodes (UV-LEDs) are difficult to achieve highly crystalline GaN because lack of suitable substrates available and needed for high-temperature deposition process. Hence, the present research is focused on the enhancement of AlN as a buffer layer for the …
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UV Laser and LED Induced Fluorescence Spectroscopy for Detection of Trace Amounts of Organics in Drinking Water and Water Sources
A UV Laser Induced Fluorescence (LIF) system, previously developed in our laboratory, was modified and used for a series of applications related to the development and optimization of UV LIF spectroscopic measurements of trace contaminants in drinking water and other water sources. Fluorescence …
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Investigation of novel methods to remove the cyanotoxin, Cylindrospermopsin, from drinking water.
… were extended to investigate the application of UV-LEDs in the photocatalysis reaction to show better efficiency.
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III-nitride nanowire light-emitting diodes: design and characterization
… relaxation. Nanowire light-emitting diodes (LEDs) with emission in the ultraviolet to visible wavelength range have recently been studied for applications in solid-state lighting, flat-panel displays, and solar-blind detectors. In this thesis, investigation of the systematic process flow of …
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Design, fabrication and characterisation of ultraviolet light-emitting diodes for biomedical applications
The efficiencies of ultraviolet (UV) light-emitting diodes (LEDs) significantly lag behind those of their blue counterparts, owing to a variety of electrical and optical challenges. There is a marked dip in performance in the wavelength range ∼320 − 340 nm, due to the difficulty in realising a high …
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Synthesis and Characterization of Luminescent Nanostructured SiOC Thin Films
… be tuned across the visible spectral range from UV-blue to red by controlling film composition. A further advantage of this method is that the thin films can be formed on Si or quartz wafers and this can serve as starting material to process more complex photonic devices such as waveguides or …
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Overcoming Longstanding Synthesis Challenges Toward Realizing the Full Device Potential of III-Nitride Semiconductors
… solar cells (InGaN), RGB LEDs (InGaN), UV LEDs and lasers (AlGaN), and high-power diodes and transistors (AlGaN). However, many of these applications remain unrealized due to challenges in growing high-quality material by traditional growth techniques like metalorganic …