A5069621921- Strong Light-Matter Interactions
- Perovskite Materials and Applications
- Molecular Junctions and Nanostructures
- Spectroscopy and Quantum Chemical Studies
- Organic Electronics and Photovoltaics
- Luminescence and Fluorescent Materials
- Photoreceptor and optogenetics research
- Thermal Radiation and Cooling Technologies
- Photochemistry and Electron Transfer Studies
- Quantum Dots Synthesis And Properties
- Synthesis and Properties of Aromatic Compounds
- Advanced Chemical Physics Studies
- Plasmonic and Surface Plasmon Research
- Organic Light-Emitting Diodes Research
- X-ray Diffraction in Crystallography
- Mechanical and Optical Resonators
- Metal-Organic Frameworks: Synthesis and Applications
- Advanced biosensing and bioanalysis techniques
- Crystallization and Solubility Studies
- Quantum, superfluid, helium dynamics
- Supramolecular Self-Assembly in Materials
- Quantum and electron transport phenomena
- Conducting polymers and applications
- Porphyrin and Phthalocyanine Chemistry
- Nanopore and Nanochannel Transport Studies
Cornell University
2019-2025
Ithaca College
2023
University of Sheffield
2016-2021
University of Cambridge
2013-2021
University of Cyprus
2021
Hangzhou Normal University
2021
Nanjing University
2021
Centre National de la Recherche Scientifique
2020
University of Mons
2020
École Nationale Supérieure de Chimie de Rennes
2020
Abstract Entanglement of states is one the most surprising and counter-intuitive consequences quantum mechanics, with potent applications in cryptography computing. In organic materials, particularly significant manifestation spin-entangled triplet-pair state, which mediates spin-conserving fission spin-0 singlet exciton into two spin-1 triplet excitons. Despite long theoretical experimental exploration, nature state inter-triplet interactions have proved elusive. Here we use a range...
Fast and highly efficient intramolecular singlet exciton fission in a pentacene dimer, consisting of two covalently attached, nearly orthogonal units is reported. Fission to triplet excitons from this ground state geometry occurs within 1 ps isolated molecules solution dispersed solid matrices. The process exhibits sensitivity environmental polarity competes with geometric relaxation the state, while subsequent decay strongly dependent on conformational freedom. near arrangement unlike any...
Singlet exciton fission is the spin-conserving transformation of one spin-singlet into two spin-triplet excitons. This multiplication mechanism offers an attractive route to solar cells that circumvent single-junction Shockley-Queisser limit. Most theoretical descriptions singlet invoke intermediate state a pair excitons coupled overall configuration, but such has never been optically observed. In solution, we show dynamics are diffusion limited and enable isolation species. concentrated...
Abstract Understanding the mechanism of singlet exciton fission, in which a separates into pair triplet excitons, is crucial to development new chromophores for efficient fission-sensitized solar cells. The challenge controlling molecular packing and energy levels solid state precludes clear determination fission pathway. Here, we circumvent this difficulty by utilizing covalent dimers pentacene with two types side groups. We report rapid intramolecular both molecules, one case via virtual...
Singlet exciton fission allows the fast and efficient generation of two spin triplet states from one photoexcited singlet. It has potential to improve organic photovoltaics, enabling coupling blue ultraviolet region solar spectrum capture energy generally lost as waste heat. However, many questions remain about underlying mechanism. The relation between intermolecular geometry singlet rate yield is poorly understood remains most significant barriers design new sensitizers. Here we explore...
Abstract While there have been numerous reports of long‐range polariton transport at room‐temperature in organic cavities, the spatiotemporal evolution propagation is scarcely reported, particularly initial coherent sub‐ps regime, where photon and exciton wavefunctions are inextricably mixed. Hence detailed process exciton‐polariton and, particular, role dark states has remained poorly understood. Here, femtosecond transient absorption microscopy used to directly image motion microcavities...
Singlet exciton fission is a spin-allowed process to generate two triplet excitons from single absorbed photon. This phenomenon offers great potential in organic photovoltaics, but the mechanism remains poorly understood. Most reports date have addressed intermolecular within small-molecular crystals. However, through appropriate chemical design chromophores capable of intramolecular can also be produced. Here we directly observe sub-100 fs activated singlet semiconducting...
Singlet fission offers the potential to overcome thermodynamic limits in solar cells by converting energy of a single absorbed photon into two distinct triplet excitons. However, progress is limited small family suitable materials, and new chromophore design principles are needed. Here, we experimentally vindicate concept diradical stabilization tunable functionalized zethrenes. All molecules series exhibit rapid formation bound, spin-entangled triplet-pair state TT. It can be dissociated...
Entanglement of states is one the most surprising and counterintuitive consequences quantum mechanics, with potent applications in cryptography computing. In organic semiconductor materials, particularly significant manifestation spin-entangled triplet-pair state, which consists a pair localized triplet excitons coupled into an overall spin-0, -1, or -2 configuration. The widely analyzed these spin-0 pair, denoted 1 (TT), was initially invoked 1960s to explain delayed fluorescence acene...
DNA amphiphile particles template formation of virus capsids and enable their loading.
Singlet fission, the process of forming two triplet excitons from one singlet exciton, is a characteristic reserved for only handful organic molecules due to atypical energetic requirement low energy excited states. The predominant strategy achieving such trait by increasing ground state diradical character; however, this greatly reduces ambient stability. Herein, we exploit Baird's rule aromaticity manipulate singlet-triplet gap and create novel fission candidates. We achieve through...
Exciton-polaritons are quasiparticles with mixed photon and exciton character that demonstrate rich quantum phenomena, novel optoelectronic devices the potential to modify chemical properties of materials. Organic materials current interest as active for their ability sustain exciton-polaritons even at room temperature. However, within organic devices, it is often 'dark' spin-1 triplet excitons dominate operation. These triplets have been largely ignored in treatments polaritons, which...
Abstract The simulation of open quantum dynamics is a critical tool for understanding how the non-classical properties matter might be functionalised in future devices. However, unlocking enormous potential molecular processes highly challenging due to very strong and non-Markovian coupling ‘environmental’ vibrations electronic ‘system’ degrees freedom. Here, we present an advanced but general computational strategy that allows tensor network methods effectively compute non-perturbative,...
The presence of energetically low-lying triplet states is a hallmark organic semiconductors. Even though they present wealth interesting photophysical properties, these optically dark significantly limit optoelectronic device performance. Recent advances in emissive charge-transfer molecules have pioneered routes to reduce the energy gap between triplets and "bright" singlets, allowing thermal population exchange them eliminating significant loss channel devices. In conjugated polymers, this...
Singlet fission in organic semiconductors causes a singlet exciton to decay into pair of triplet excitons and holds potential for increasing the efficiency photovoltaic devices. In this combined experimental theoretical study, we reveal that covalent dimer semiconductor tetracene undergoes activated by qualitatively different mechanisms depending on solvent environment. We show intramolecular vibrations are an integral part mechanism, giving rise mixing between charge transfer excitations....
The optical properties of a series strongly coupled microcavities containing the fluorescent molecular dye BODIPY‐Br (bromine‐substituted boron‐dipyrromethene) dispersed into transparent dielectric matrix are explored, with each cavity having different exciton–photon detuning. Using temperature dependent emission, time‐resolved spectroscopy, white‐light reflectivity, and measurements fluorescence quantum yield, population polaritons is explored along lower polariton branch. It found that...
The crystal packing of organic chromophores has a profound impact on their photophysical properties. Molecular engineering is generally incapable producing precisely spaced arrays molecules for use in photovoltaics, light-emitting diodes, and sensors. A promising alternative strategy the incorporation into crystalline metal–organic frameworks (MOFs), leading to matrix coordination-induced emission (MCIE) upon confinement. However, it remains unclear how precise arrangement defects dictates...
Covalent dimers, particularly pentacenes, are the dominant platform for developing a mechanistic understanding of intramolecular singlet fission (iSF). Numerous studies have demonstrated that photoexcited state in these structures can rapidly and efficiently undergo exciton multiplication to form correlated pair triplets within single molecule, with potential applications from photovoltaics quantum information science. One most significant barriers limiting such dimers is fast recombination...
Abstract Exciton polaritons, arising from the interaction of electronic transitions with confined electromagnetic fields, have emerged as a powerful tool to manipulate properties organic materials. However, standard experimental and theoretical approaches overlook significant energetic disorder present in most materials now studied. Using conjugated polymer P3HT model platform, degree is systematically tuned corresponding redistribution photonic character within polariton manifold observed....
Abstract Organic light‐emitting diodes (OLEDs) have redefined lighting with their environment‐friendliness and flexibility. However, only 25% of the electronic states organic molecules can emit light upon electrical excitation, limiting overall efficiency OLEDs. Strong light–matter coupling, achieved by confining within OLEDs using mirrors, creates hybrid light‐matter known as polaritons, which could “activate” remaining 75% triplet states. Here, triplet‐to‐polariton transition is studied...