2017/05/16 by Roel Tempelaar, Tempelaar, Roel, Thomas L. C. Jansen +3
Chemistry · Physics and Astronomy · #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Semiconductor Quantum Structures and Devices #Spectroscopy and Laser Applications #Spectroscopy and Quantum Chemical Studies
paper · pdf · doi:10.48550/arxiv.1705.05861
openalex publication_date 2017/05/16 · openalex created_date 2022/10/04 · openalex updated_date 2026/07/28
We theoretically demonstrate a strong dependence of the annihilation rate between (singlet) excitons on the sign of dipole-dipole couplings between molecules. For molecular H-aggregates, where this sign is positive, the phase relation of the delocalized two-exciton wavefunctions causes a destructive interference in the annihilation probability. For J-aggregates, where this sign is negative, the interference is constructive instead, as a result of which no such coherent suppression of the annihilation rate occurs. As a consequence, room temperature annihilation rates of typical H- and J-aggregates differ by a factor of ~3, while an order of magnitude difference is found for low-temperature aggregates with a low degree of disorder. These findings, which explain experimental observations, reveal a fundamental principle underlying exciton-exciton annihilation, with major implications for technological devices and experimental studies involving high excitation densities.