Charge transfer excitons in a donor–acceptor amphidynamic crystal: the role of dipole orientational order
| Autor: | Enrico Da Como, Massimiliano Comin, Joshua W. R. Macdonald, Gabriele D'Avino, Gabriele Kociok-Köhn, Pavlos G. Lagoudakis, Christopher R. Bowen, Giacomo Piana, Elizabeth von Hauff |
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| Přispěvatelé: | University of Bath [Bath], School of Physics and Astronomy [Southampton], University of Southampton, Théorie de la Matière Condensée (TMC), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA), Department of Physics and Astronomy [Amsterdam], Vrije Universiteit Amsterdam [Amsterdam] (VU), Photo Conversion Materials, LaserLaB - Energy |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Phase transition
Materials science Photoluminescence Exciton 02 engineering and technology 010402 general chemistry 01 natural sciences Molecular physics Condensed Matter::Materials Science Molecular solid General Materials Science SDG 7 - Affordable and Clean Energy Electrical and Electronic Engineering [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ComputingMilieux_MISCELLANEOUS Process Chemistry and Technology [CHIM.MATE]Chemical Sciences/Material chemistry 021001 nanoscience & nanotechnology Acceptor 0104 chemical sciences Organic semiconductor Dipole Mechanics of Materials Absorption band 0210 nano-technology |
| Zdroj: | Materials Horizons Materials Horizons, cRoyal Society of Chemistry, 2020, 7 (11), pp.2951-2958. ⟨10.1039/d0mh01044h⟩ Macdonald, J W R, Piana, G, Comin, M, Von Hauff, E, Kociok-Köhn, G, Bowen, C, Lagoudakis, P, D'Avino, G & Da Como, E 2020, ' Charge transfer excitons in a donor-acceptor amphidynamic crystal : The role of dipole orientational order ', Materials Horizons, vol. 7, no. 11, pp. 2951-2958 . https://doi.org/10.1039/d0mh01044h Materials Horizons, 7(11), 2951-2958. Royal Society of Chemistry |
| ISSN: | 2051-6347 |
| DOI: | 10.1039/d0mh01044h⟩ |
| Popis: | Large amplitude motions in molecular solids are responsible for anomalous electrical characteristics in amphidynamic crystals. We study the effect of orientational dipolar disorder on charge transfer excitons (CTEs) in a donor-acceptor amphidynamic co-crystal of perylene-tetrabromophthalic anhydride (-TBPA). This co-crystal offers long range positional order of alternating donor and acceptor molecular entities arranged in stacks. Further it has a phase transition at 250 K due to progressive freezing of the dipolar orientational motion in the TBPA permanent dipole. The optical absorption band and photoluminescence at the semiconductor gap consists of at least three energetically separated CTE resonances that cover a spectral range of more than 400 meV. As the temperature is lowered below the phase transition the CTE band remains broad, but shows a shift of ∼150 meV to higher energy. On the basis of optical reflectivity, photoluminescence, and model calculations we interpret the room temperature CTE band as a collection of resonances in which at least one the nearest neighbour dipoles to the CTE is flipped from their lowest energy configuration. This first comprehensive optical investigation on an amphidynamic co-crystal demonstrates the importance of understanding the role of permanent dipoles in the CTE photophysics of organic semiconductors. This journal is |
| Databáze: | OpenAIRE |
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