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 16 of 16 for “"triplet-triplet annihilation"”.
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Triplet-Triplet Annihilation Upconversion in Solid-State Organic-Inorganic Ureasil Polymer Hosts
Triplet–triplet-annihilation upconversion (TTA-UC) has attracted significant attention as an approach to harvest low energy solar photons that cannot be captured by conventional photovoltaic devices. However, device integration requires the design of solid-state TTA-UC materials that combine high …
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Development in utilizing singlet fission and triplet-triplet annihilation to improve solar cell efficiency
… warming. In this thesis, singlet fission and triplet-triplet annihilation would be discussed and studied to increase solar cell power conversion efficiency. Singlet fission splits a singlet exciton into two lower energy triplet excitons. This energy down conversion is efficient and have shown …
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Thiol-Ene Click Chemistry for Solid State Triplet-Triplet Annihilation Upconversion and Parts-Per-Billion Pyrophosphate Sensing in Artificial Seawater
… click photopolymerization. The advancement of triplet-triplet annihilation based upconversion (TTA-UC) in emerging technologies necessitates the development of solid-state systems that are readily accessible and broadly applicable. We demonstrate that thiol-ene click chemistry can be used as a …
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Spectroscopic Study of Triplet Exciton Dynamics at the Hybrid Organic-Inorganic Interface
The control and utilisation of spin-triplet excitons in organic semiconductors is highly sought after for the next generation of Optoelectronic applications. Of particular interest is the utilisation of these photoexcited states in the singlet-fission photon-multiplier and triplet-triplet …
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Materials, photophysics and device designs for high efficiency photovoltaics
… singlet fission sensitized solar cells and (iii) triplet-triplet annihilation assisted upconversion. Following a review of the relevant background theory for organic semiconductors, colloidal quantum dot (CQD) semiconductors and perovskite semiconductors, we discuss their applications in …
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Infrared-to-visible upconversion in hybrid thin films of colloidal nanocrystals and organic molecules
… DBP molecules. Upconversion is realized via triplet-triplet annihilation (TTA) in rubrene sensitized by the NCs. We demonstrate that compared to the previous all-molecular upconverting systems, the use of inorganic NCs helps extend the excitation wavelength into the infrared and offers simple …
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Molekulinių spinduolių optimizacija naujos kartos organiniams šviestukams /
… fluorescent emitters, especially those utilising triplet-triplet annihilation, has efficiencies comparable to those of phosphorescent OLEDs. Few years ago, a new class of molecular emitters was offered, where the thermal activation of triplet excitons are used for the reversible intersystem …
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Optimization of molecular emitters for new generation OLEDs /
… fluorescent emitters, especially those utilising triplet-triplet annihilation, has efficiencies comparable to those of phosphorescent OLEDs. Few years ago, a new class of molecular emitters was offered, where the thermal activation of triplet excitons are used for the reversible intersystem …
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Strategies for High-Performance Solid-State Photon Upconversion
… fundamental limit from the upconverting process—triplet-triplet annihilation (TTA)—itself. In this thesis, we investigate strategies to tackle the limitations in solid-state photon upconversion. First, optical absorption is enhanced via embedding an archetypical solid-state infrared-to-visible …
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Developing microwave probes for investigating opto-electronic processes in photovoltaic materials
… processes, such as Singlet-Fission, Triplet-Triplet annihilation, and spin-dependent recombination in organic semiconductors. We investigate the charge carrier mobilities and lifetimes of CH3NH3PbI3 lead halide perovskite thin films using TRMC. The spectrally resolved TRMC apparatus …
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I. Kinetic Modeling of Surface Reactions II. Computational Design of Organic Semiconductors
… activated delayed fluorescence (TADF) and triplet-triplet annihilation (TTA), which convert the nonemissive triplet excitons into emissive singlet excitons. First, we introduce a simple four-state model of TADF. The model predicts that it is possible to realize adiabatic singlet (S₁) and …
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Excitonic spin engineering in optoelectronic devices
… turn to the reverse process of singlet fission: triplet-triplet annihilation. We utilize colloidal nanocrystals as the sensitizer and rubrene as the annihilator. The use of colloidal nanocrystals as the sensitizer allows us to minimize energetic loss and extend deeper into the infrared as …
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Photophysical Studies of Active Layer Compositions in Organic Solar Cells
… material. OSCs also have a high tendency to form triplet states which contribute to non-radiative voltage losses and limit charge extraction in working solar cells. We finally propose integrating photon upconversion via triplet-triplet annihilation (TTA-UC) into an OSC to recycle the low-energy …
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Design and Synthesis of Photoactive Metal-Organic Frameworks for Photon Upconversion and Energy Transfer Studies
… for photon upconversion through sensitized triplet-triplet annihilation (TTA-UC) was probed in the three anthracene-based MOFs. The MOFs were surface-modified with Pd(II) mesoporphyrin IX (PdMP) as the triplet sensitizer. Upconverted emission from the 9,10-MOF was observed, with a quantum …
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The effects of strain on the electronic and optical properties of rubrene single crystals
… is explained in terms of the singlet fission and triplet-triplet annihilation processes that are responsible for a majority of the emission in rubrene. By altering the proportion of singlets that undergo fission and subsequent fusion the overall intensity can be drastically changed. Again, the …
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The spectroscopy and the photophysics of 1,2-benzazulene, a derivative of azulene.
The photophysics and the spectroscopy of 1,2-benzazulene were studied both in the liquid and solid phase using azulene for comparison, with the interest of investigating its quenching mechanism from the S2 state and the possibility of it undergoing singlet fission via S2 + S0 → 2T1. To understand …