| Autor: |
Lin LC; Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States., Dill RD; Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States., Thorley KJ; Department of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States., Parkin SR; Department of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States., Anthony JE; Department of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States., Johnson JC; National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States.; Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, Colorado 80309, United States., Damrauer NH; Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States.; Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, Colorado 80309, United States. |
| Abstrakt: |
Tetraceno[2,3- b ]thiophene is regarded as a strong candidate for singlet fission-based solar cell applications due to its mixed characteristics of tetracene and pentacene that balance exothermicity and triplet energy. An electronically weakly coupled tetraceno[2,3- b ]thiophene dimer (Et 2 Si(TIPSTT) 2 ) with a single silicon atom bridge has been synthesized, providing a new platform to investigate the singlet fission mechanism involving the two acene chromophores. We study the excited state dynamics of Et 2 Si(TIPSTT) 2 by monitoring the evolution of multiexciton coupled triplet states, 1 TT to 5 TT to 3 TT to T 1 + S 0 , upon photoexcitation with transient absorption, temperature-dependent transient absorption, and transient/pulsed electron paramagnetic resonance spectroscopies. We find that the photoexcited singlet lifetime is 107 ps, with 90% evolving to form the TT state, and the complicated evolution between the multiexciton states is unraveled, which can be an important reference for future efforts toward tetraceno[2,3- b ]thiophene-based singlet fission solar cells. |
