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 30 for “"Colloidal quantum dot"”.
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All inorganic colloidal quantum dot LEDs
This thesis presents the first colloidal quantum dot light emitting devices (QD-LEDs) with metal oxide charge transport layers. Colloidally synthesized quantum dots (QDs) have shown promise as the active material in optoelectronic devices because of their tunable, narrow band emission. To date, the …
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Nanostructured architectures for colloidal quantum dot solar cells
… ordered bulk heterojunction architecture for colloidal quantum dot (QD) solar cells. Quantum dots are solution-processed nanocrystals whose tunable bandgap energies make them a promising active-layer candidate for next-generation optoelectronic devices, including solar cells and light-emitting …
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Temperature Characterization of Colloidal Quantum Dot Light Emitting Diodes
Colloidal quantum dot light emitting diodes reveal to be promising candidates for the next generation of display technologies. Their brighter emissions, greater color purity, and higher efficiency make them highly desirable in consumer electronics. As such, research into the performance and …
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Energy level engineering in colloidal quantum dot solar cells
Lead sulfide colloidal quantum dots (PbS QDs) possess a uniquely tunable set of electronic properties that has generated considerable interest in their use as active materials in lightweight, flexible, solution-processed photovoltaics. The bandgap of PbS QDs can be tuned across the entire range …
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Charge transport in nanopatterned PbS colloidal quantum dot arrays
… charge transport in nanopatterned arrays of PbS colloidal quantum dots using conventional two-probe measurements and an integrated charge sensor. PbS dots are synthesized in solution with an organic ligand or cap that serves to passivate the surface of the dot, provide a tunnel barrier as well as …
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Colloidal quantum dot based light emitting devices on silicon substrate
… of light sources within CMOS circuitry. Colloidal semiconductor nanocrystals have narrow emission spectra which makes them an excellent choice for active media in optoelectronic applications. Moreover, solution processability of colloidal quantum dots makes processing and integration on …
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Transfer printing based microassembly and colloidal quantum dot film integration
… photolithography. Delicate nanomaterials such as colloidal quantum dots cannot be processed via monolithic microfabrication. In this context, transfer printing has emerged as a method to transfer heterogeneous material pieces from their mother substrates to a foreign substrate utilizing a …
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Efficiency loss mechanisms in colloidal quantum-dot light-emitting diodes
Saturated and tunable emission colors make colloidal quantum-dot light-emitting diodes (QD-LEDs) interesting for the next generation of display and lighting technologies. However, there still remain various hurdles to the commercialization of QD-LEDs, including their relatively low external quantum …
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Architecting the Optics, Energetics and Geometry of Colloidal Quantum Dot Photovoltaics
… a low cost solution to global energy concerns. Colloidal quantum dots are one material that can be easily synthesized in and deposited from solution. These nanoparticles also offer the unique ability to select the desired optical and electrical characteristics, all within the same materials …
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Understanding colloidal quantum dot excitation with solution photon correlation fourier spectroscopy
Colloidal quantum dots (CQDs) have useful absorption and emission properties but exist in inhomogenous batches. Solution photon correlation fourier spectroscopy (S-PCFS) combines interferometry with fluorescence correlation spectroscopy (FCS) to measure the spectral correlation of the average …
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Theoretical characterisation of spheroidal PbSe/PbS Core/Shell colloidal quantum dot heterostructures
Nanocrystal quantum dots (NQDs) show great promise in the advancement of the field of photovoltaics. While the maximum efficiency of conventional solar cell (SC) devices is limited to ∼ 31% (Shockley-Queisser limit), devices based on NQDs may attain a maximal thermodynamic efficiency of 42% through …
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Exploring the mechanism of interfacial self-assembly of colloidal quantum dot nanoparticles
Colloidal nanoparticles at the interface of two immiscible fluids experience certain restrictions on their position and orientation. This property is exploited to create long-range, coherent assemblies of quasi-2D super-structures that are known to possess strong correlations between their packing …
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Development of low-temperature solution-processed colloidal quantum dot-based solar cells
… organic semiconductors and inorganic colloidal quantum dots (QDs) are potential alternatives to conventional solar cells fabricated via vacuum or high-temperature sintering processes for large-area, high-throughput, and low-cost manufacturing. In this work, we explored two types of …
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Performance limits for colloidal quantum dot and emerging thin-film solar cells
… for most emerging PV technologies-including colloidal quantum dots (QDs), perovskites, and organics-power conversion eciency and stability remain major obstacles to commercial development. In this thesis, we evaluate the long-term potential of emerging thin-film PV technologies, focusing on …
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Development of colloidal quantum dot and lead halide perovskite light emitting devices
… semiconductors, such as organic molecules, colloidal quantum dots (QDs) and lead halide perovskites, have emerged as top candidates for light emitting materials. One key feature of these materials is their bandgap tunability, e.g. via size or chemical composition, allowing for their emission …
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Design and optimization of colloidal quantum dot solids for enhanced charge transport and photovoltaics
Colloidal quantum dots (CQDs) have attracted much attention due to their distinctive optical properties such as wide spectral responses and tunable absorption spectra with simple size control. These properties, together with the advantages of solution processing and superior robustness to organic …
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High open-circuit voltage in heterojunction photovoltaics containing a printed colloidal quantum-dot photosensitive layer
… Using printing methods, we deposit a layer of colloidal cadmium selenide (CdSe) quantum dots (QDs) onto a wide band-gap organic hole-transporting thin film of N,N'-bis(3-methylphenyl)-N,N'-bis-(phenyl)-9,9-spirobiuorene (spiro-TPD) in order to form a unique planar heterojunction photovoltaic …
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First-principles studies of defects in colloidal nanocrystals
… lead halide perovskite PV, organic PV and colloidal quantum dot (CQD) PV. Colloidal quantum dots are semiconducting nanocrystals that exhibit size tunable electronic and optical properties.
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Solution-processable, mechanically-flexible lasers
… materials are used: organic semiconductors and colloidal quantum dots. Encapsulation schemes compatible with the mechanical flexibility of the final devices, e.g. using transparent polymers or flexible glass membranes, are proposed and studied in order to extend the operational lifetime of the …
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Colloidal Semiconductor Nanocrystals: A Study of the Syntheses of and Capping Structures for CdSe
Luminescent quantum dots (QDs) or rods are semiconductor nano-particles that may be used for a wide array of applications such as in electro-optical devices, spectral bar coding, tagging and light filtering. In the case under investigation, the nano-particles are cadmium-selenide (CdSe), though …
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