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Showing 1 to 20 of 375 for “"singlet"”.
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Singlet fission photovoltaics
… than the bandgap lose energy by thermalization. Singlet exciton fission splits a high-energy molecular excitation ("singlet" exciton) into a pair of lowenergy ones ("triplet" excitons). In solar cells, it promises to generate two electrons per photon, potentially overcoming the singlet junction …
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Study of Singlet-Delta Molecular Oxygen
Made available in DSpace on 2017-07-06T18:55:43Z (GMT). No. of bitstreams: 2 Ottinger_Catherine_A_MS.pdf: 20663206 bytes, checksum: a3022176843d2c08f46a2823faa9ad74 (MD5) license.txt: 4813 bytes, checksum: 715c4321821a960fa1a1e91d2ac7ebce (MD5) Previous issue date: 1983
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Microchemical systems for singlet oxygen generation
… of iodine atoms is collisionally pumped by singlet delta oxygen molecules, which are created through the catalyzed multiphase reaction of hydrogen peroxide and chlorine. Currently the use of COIL technology is limited by size and efficiency issues. This thesis seeks to use MEMS technology …
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Quantum State Singlet-Triplet Character Control in 7Li2
… in each state being a mixture of the pure singlet and pure triplet states. The initial mixing coefficients are governed by the strength of the spin-orbit coupling between the two levels. In lithium dimer, this mixing is very weak; the nominal singlet (triplet) state is initially 87% singlet …
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Singlet Fission in Pechmann Dyes and Molecular Oligomers
Singlet fission is an ultrafast photophysical process in organic systems whereby a high-energy photoexcited singlet exciton converts to two low-energy triplet excitons through a spin-conserving pathway. When integrated into photovoltaics, singlet fission offers the opportunity to mitigate …
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Singlet exciton fission : applications to solar energy harvesting
Singlet exciton fission transforms a single molecular excited state into two excited states of half the energy. When used in solar cells it can double the photocurrent from high energy photons increasing the maximum theoretical power efficiency to greater than 40%. The steady state singlet fission …
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Electronic Structure Modelling of Singlet Fission in Organic Photovoltaics
Singlet fission is a multiple-exciton-generation process found in organic materials that could help to enhance the efficiency of future photovoltaic devices, by overcoming the Shockley-Queisser limit. In spite of considerable experimental and theoretical attention, different aspects of the process …
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Singlet Exciton Fission in Acene Dimer and Diradicaloid Molecules
… of triplet excitons following photoexcitation, singlet exciton fission, in three different acene dimers and diradicaloids. In pentacene and tetracene dimers, we investigate their mechanism of singlet fission. In a series of diradicaloids, we study the relation between molecular structure, …
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Oxidation of waxes using microwave-generated singlet molecular oxygen
… then takes place via a free radical process. Singlet molecular oxygen is a higher-energy state species of oxygen, in which the two electrons in the π* 2p antibonding molecular orbitals, while remaining unpaired, are excited to antiparallel spin. Reactions of singlet oxygen are very …
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Designing Planar Silicon Solar Cells for Singlet Fission Sensitization
Singlet fission (SF)-sensitized silicon (Si) solar cells offer a path towards surpassing the Shockley-Queisser efficiency limit for single-junction solar cells. However, realizing efficient charge transfer from the SF material to Si remains a significant challenge that requires careful interface …
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Investigating the Photophysics of New and Stable Singlet Fission Materials
… our investigations into the mechanism of singlet exciton fission, examining the effects of morphology, aromaticity, and photoluminescence yield on the fission process, and developing generalised principles to aid the design of new materials. Singlet fission is the process of forming two …
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Singlet Oxygen Production and Its Kinetics in Nanoparticle-Photosensitizer Hybrid Systems
… know it. However, in its lowest excited state, singlet oxygen is a powerful cytotoxic agent capable of damaging DNA, proteins, and cell membranes. In medicinal context, production of singlet oxygen from light-activated drugs (photosensitizers) has been used to various degrees in photodynamic …
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Efficient Organic Light-emitting Diodes with Singlet, Triplet and Doublet Excitons
… are determined by the spin state including singlets, triplets and doublets. Triplet excitons are regarded as dark states due to their spin-forbidden decay process, whereas effective triplet harvesting or triplet circumvention can help to improve the OLED performance. In this thesis, methods …
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Synthesis and Optical Characterisation of Diphenylhexatriene Derived Intramolecular Singlet Fission Materials
… of the semiconductor is lost to thermalisation. Singlet fission (SF) is a physical process in certain organic materials that enables the production of two excited states, each with triplet multiplicity, from a lone photoexcited singlet state. It has been widely recognised that integration of an …
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Light-activated materials for singlet oxygen generation and the degradation of pollutants
… these doped membranes generate the ROS singlet oxygen (SO), and through spectrofluorometric and chromatographic measurements, it was determined that propranolol and several pollutants were degraded. This work demonstrates that practical light-activated PS-doped membranes can be used to …
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Design of Singlet Fission Chromophores through the Introduction of N-Oxyl Fragments.
Singlet fission is a highly desired phenomenon in photovoltaics. In the fission process, one short-lived singlet exciton splits to two long-lived triplet excitons. Generating a larger number of longer-lived excitons, singlet fission has the potential to enhance the photoelectric conversion …
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Quantum error modelling and correction in long distance teleportation using singlet states
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.
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Part One: Ozonolysis of Diphenylvinylene Carbonate. Synthesis and Thermolysis of Dibenzoyl Monoperoxycarbonate. Part Two: Singlet Oxygen: The Lifetime of Singlet Oxygen in Solution and Its Reaction With Ene-Type Olefins
The reaction of ozone and diphenylvinylene carbonate is found to give dibenzoyl monoperoxycarbonate in good yield. A mechanism for the formation of this peroxide is proposed and is consistent with the Criegee mechanism for ozonolysis of most olefins. The thermolysis of dibenzoyl monoperoxycarbonate …
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Singlet oxygen generating luminescent lanthanide complexes with naphthalimide-based and oligothiophene-based sensitizers
… lanthanide (LnIII) complexes that also generate singlet oxygen (1O2) are of interest to medical, biological, and analytical fields, as they can provide cytotoxicity and luminescence using light excitation. Because of the interest in these compounds, systematic studies were used to help understand …
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