| Autor: |
Margulies EA; Department of Chemistry and Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States., Logsdon JL; Department of Chemistry and Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States., Miller CE; Department of Chemistry and Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States., Ma L; Department of Chemistry and Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States., Simonoff E; Department of Chemistry and Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States., Young RM; Department of Chemistry and Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States., Schatz GC; Department of Chemistry and Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States., Wasielewski MR; Department of Chemistry and Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States. |
| Abstrakt: |
Singlet exciton fission (SF) in organic chromophore assemblies results in the conversion of one singlet exciton (S 1 ) into two triplet excitons (T 1 ), provided that the overall process is exoergic, i.e., E(S 1 ) > 2E(T 1 ). We report on SF in thin polycrystalline films of two terrylene-3,4:11,12-bis(dicarboximide) (TDI) derivatives 1 and 2, which crystallize into two distinct π-stacked structures. Femtosecond transient absorption spectroscopy (fsTA) reveals a charge-transfer state preceding a 190% T 1 yield in films of 1, where the π-stacked TDI molecules are rotated by 23° along an axis perpendicular to their π systems. In contrast, when the TDI molecules are slip-stacked along their N-N axes in films of 2, fsTA shows excimer formation, followed by a 50% T 1 yield. |
