Aggregation-induced intersystem crossing: a novel strategy for efficient molecular phosphorescence

• DOI: 10.1039/c6nr03656b
• Publication Date: 2016-08-12T15:01:19Z
• Authors: Li Yang; Xijun Wang; Guozhen Zhang; Xiaofeng Chen; Guoqing Zhang; Jun Jiang
• Keywords: Intersystem crossing; Singlet fission

"Aggregation-caused quenching" (ACQ) and "aggregation-induced emission" (AIE) are two well-known mechanisms for polymer luminescence. Here we proposed an alternative mechanism termed intersystem crossing" (AI-ISC). By aggregating certain fluorescent dye molecules, one can improve the energy matches between excited singlet triplet states so as to promote crossing (ISC) rate, consequently prolong lifetime of electrons by steering them into states. First-principles calculations suggested that enhanced ISC rate could substantially molecular phosphorescence in aggregated systems originally later validated experimental measurement. Meanwhile, emission spectra experience a red shift along with aggregation, providing convenient knob tune wavelength. The AI-ISC may open up new design approach emerging luminescent material applications.