0000000000003258

AUTHOR

Egmont Rohwer

showing 3 related works from this author

Photocycle of Excitons in Nitrogen-Rich Carbon Nanodots: Implications for Photocatalysis and Photovoltaics

2020

Nitrogen-rich carbon nanodots have emerged as promising nanomaterials for a wide range of applications where a highly emissive and photoactive material with low toxicity and cost-effectiveness is required. One of their hallmarks is indeed a bright, tunable fluorescence of excitonic nature. Disentangling the origin of their optical absorption and fluorescence properties and uncovering relaxation channels and interactions with solvents are some of the most debated issues in the field. Uncovering these aspects is essential for targeted applications, especially in the fields of photocatalysis but also photovoltaics and optoelectronics. Here, we present dedicated transient absorption measurement…

Materials sciencecarbon nanodots carbon nitride surface exciton core exciton photocycle ultrafast spectroscopy exciton emission530 Physicsbusiness.industryExcitonNanotechnologyNanomaterialschemistry.chemical_compoundchemistryPhotovoltaics540 ChemistryUltrafast laser spectroscopyPhotocatalysisGeneral Materials ScienceNanodotbusinessAbsorption (electromagnetic radiation)Carbon nitrideACS Applied Nano Materials
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Disentangling size effects and spectral inhomogeneity in carbon nanodots by ultrafast dynamical hole-burning.

2018

Carbon nanodots (CDs) are a novel family of nanomaterials exhibiting unique optical properties. In particular, their bright and tunable fluorescence redefines the paradigm of carbon as a "black" material and is considered very appealing for many applications. While the field keeps growing, understanding CDs fundamental properties and relating them to their variable structures becomes more and more critical. Two crucial problems concern the effect of size on the electronic structure of CDs, and to what extent their optical properties are influenced by structural disorder. Furthermore, it remains largely unclear whether traditional concepts borrowed from the photo-physics of semiconductor qua…

Potential wellMaterials scienceField (physics)530 Physicschemistry.chemical_element02 engineering and technologyElectronic structure010402 general chemistry021001 nanoscience & nanotechnologyCondensed Matter::Mesoscopic Systems and Quantum Hall Effect620 Engineeringcarbon nanodots fluorescent nanomaterials pump probe carbon materials01 natural sciences0104 chemical sciencesNanomaterialsCondensed Matter::Materials SciencechemistryChemical physicsAtomic electron transitionFemtosecond540 ChemistryGeneral Materials Science0210 nano-technologyCarbonUltrashort pulseNanoscale
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The interaction of photoexcited carbon nanodots with metal ions disclosed down to the femtosecond scale

2017

Fluorescent carbon nanodots are a novel family of carbon-based nanoscale materials endowed with an outstanding combination of properties that make them very appealing for applications in nanosensing, photonics, solar energy harvesting and photocatalysis. One of the remarkable properties of carbon dots is their strong sensitivity to the local environment, especially to metal ions in solution. These interactions provide a testing ground for their marked photochemical properties, highlighted by many studies, and frequently driven by charge transfer events. Here we combine several optical techniques, down to femtosecond time resolution, to understand the interplay between carbon nanodots and aq…

Materials scienceQuenching (fluorescence)530 Physicschemistry.chemical_elementNanotechnology02 engineering and technology620 Engineering010402 general chemistry021001 nanoscience & nanotechnologyElementary charge01 natural sciences0104 chemical sciencesIonElectron transferchemistryChemical physicsFemtosecondPhotocatalysisGeneral Materials ScienceMaterials Science (all)0210 nano-technologyGround stateCarbonNanoscale
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