Effective Negative Diffusion of Singlet Excitons in Organic Semiconductors
| Autor: | Alexei Halpin, Jaime Gómez Rivas, Alberto G. Curto, Anton Matthijs Berghuis, Shaojun Wang, T. V. Raziman |
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| Přispěvatelé: | Surface Photonics, Photonics and Semiconductor Nanophysics, Nano-Optics of 2D Semiconductors, Center for Terahertz Science and Technology Eindhoven, ICMS Core |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Physics
Letter Anomalous diffusion Exciton 02 engineering and technology Nanosecond 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 01 natural sciences Molecular physics 0104 chemical sciences Photoexcitation Organic semiconductor chemistry.chemical_compound Condensed Matter::Materials Science Tetracene chemistry General Materials Science Singlet state Physical and Theoretical Chemistry Diffusion (business) 0210 nano-technology |
| Zdroj: | The Journal of Physical Chemistry Letters The Journal of Physical Chemistry Letters, 12(4), 1360-1366. American Chemical Society |
| ISSN: | 1948-7185 |
| Popis: | Using diffraction-limited ultrafast imaging techniques, we investigate the propagation of singlet and triplet excitons in single-crystal tetracene. Instead of an expected broadening, the distribution of singlet excitons narrows on a nanosecond time scale after photoexcitation. This narrowing results in an effective negative diffusion in which singlet excitons migrate toward the high-density region, eventually leading to a singlet exciton distribution that is smaller than the laser excitation spot. Modeling the excited-state dynamics demonstrates that the origin of the anomalous diffusion is rooted in nonlinear triplet–triplet annihilation (TTA). We anticipate that this is a general phenomenon that can be used to study exciton diffusion and nonlinear TTA rates in semiconductors relevant for organic optoelectronics. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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