Opposite Anisotropy Effects of Singlet and Triplet Exciton Diffusion in Tetracene Crystal

• Published in: ChemistryOpen (Weinheim) Vol. 5; no. 3; pp. 201 - 205
• Main Authors: Xie, Xiaoyu, Ma, Haibo
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01.06.2016; John Wiley and Sons Inc
• Subjects: Anisotropy; Communication; Communications; Coulomb friction; Couplings; Diffusion; Exchange; exciton diffusion; Excitons; News; Optoelectronics; Organic crystals; organic solar cells; tetracene; organic solar cells; exciton diffusion; tetracene; optoelectronics; anisotropy
• ISSN: 2191-1363; 2191-1363
• DOI: 10.1002/open.201500214

We observe the diffusion anisotropy difference between singlet and triplet excitons in organic crystals; that is, singlet and triplet excitons may have completely different spatial direction preference for diffusion. This phenomenon can be ascribed to the distinct dependence of different excitonic couplings (Coulomb Förster vs. exchange Dexter) existing in singlet and triplet excitons on their intermolecular distance and intermolecular orientation. Such a discovery provides insights for understanding the fundamental photophysical process in a vast range of organic condensed‐phase systems and optimizing the efficiency of organic optoelectronic materials. Some exciton news! Anisotropy difference for singlet and triplet excitons is shown to occur in organic crystals, ascribed to their distinct excitonic coupling mechanisms (Coulomb Förster vs. exchange Dexter). Such a finding provides a new framework to understand a vast range of photophysical problems and optimize the energy transfer efficiency of organic optoelectronic materials.