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Showing 1 to 20 of 50 for “"singlet fission"”.
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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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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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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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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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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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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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Coherence and Singlet Fission of TIPS-Pentacene Probed by Two-dimensional Electronic Spectroscopy
… solutions and solids, TIPS-Pn undergoes singlet fission (SF), an exciton multiplicative process that has the potential to increase the efficiency of photovoltaic devices by reducing energy loss through thermalisation. We use dilute solutions of TIPS-Pn to characterise the singlet states …
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DNA Directed Organic Semiconductor Interactions Controlling Excitons, Charge Transfer States, and Singlet Fission
… and electron-acceptor on DNA. Finally, singlet-fission active molecules were attached to DNA. This process generates two triplet excitons from one singlet exciton. The evolution of this process was tracked using time-resolved optical and magnetic spectroscopy. The combined observations …
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Ultrafast Spectroscopy of Organic Semiconductors: Singlet Fission and Nonfullerene Acceptors for Organic Photovoltaics
… The first takes advantage of a process called singlet exciton fission, and the second embodies an exodus from the fullerene electron acceptors prominent in organic solar cells. Indeed, this versatile class of tunable small molecules are aptly termed nonfullerene acceptors. However, both …
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Synthesis and Characterisation of Singlet Fission and Open-Shell Materials for Optoelectronic Application
Indolonaphthyridine materials for singlet fission were systematically investigated. Firstly, cibalackrot was investigated as a singlet fission material. Single crystals of cibalackrot revealed insufficient electronic coupling was inhibiting singlet fission in the solid-state. A synthetically …
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Singlet Fission Organic Solar Cell with Long-Wavelength Absorption Using Non-fullerene Acceptors
Organic solar cells made with singlet exciton fission materials are able to convert a single photon into two charges. Paired with a long-wavelength absorbing acceptor material, singlet fission materials enable solar cells that exhibit the quantum efficiency benefits of a multi-junction solar cell, …
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Modulated Magnetic Field Effects, Molecular Design, and Indigoids: A Mechanistic Study of Singlet Fission
Singlet fission has the potential to significantly enhance the efficiency of photovoltaic light harvesting of silicon solar cells beyond the Shockley-Queisser limit. The progress of this technology has been hindered by the limited selection of suitable molecules that can undergo singlet fission, …
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Development in utilizing singlet fission and triplet-triplet annihilation to improve solar cell efficiency
… gas that causes global 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 …
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Pushing the Boundaries of Endothermic Singlet Fission in Organic Semiconductors through Structure and Energetic Control
Singlet exciton fission (SF) is an exciton multiplication process in organic semiconductors in which a photoexcited singlet exciton is converted to two triplet excitons. SF based solar cells help break the Shockley-Quisser limit as high energy photons are used to generate two electron-hole pairs …
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Interfacial engineering and spectroscopy of spin-triplet excitons for singlet fission sensitization of silicon solar cells
… loss of a third of all incident solar energy. Singlet exciton fission, an energy-splitting process that converts single high-energy photons into multiple lower-energy excited states, has the capability to reduce thermalization losses and boosts the maximum silicon solar cell efficiency from …
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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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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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Singlet exciton fission, a multi-exciton generation process, in organic semiconductor solar cells
… of a multiple exciton generation process, singlet exciton fission, to work around the Shockley-Queisser limit, according to which, all single junctions cells have a theoretical efficiency limit of 33.7%. This is the first implementation of a singlet fission photovoltaic. We measured a …
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Quantum efficiency and fission rate in tetracene
Using singlet fission in a photovoltaic cell, the theoretical energy conversion efficiency limit is larger than the Shockley-Queisser limit due to two excitons produced with one incident photon. In a singlet fission material, an absorbed photon excites a singlet exciton and then split into two …
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