Charge-transfer biexciton annihilation in a donor-acceptor co-crystal yields high-energy long-lived charge carriers.

Autor: Schlesinger I; Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA m-wasielewski@northwestern.edu., Powers-Riggs NE; Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA m-wasielewski@northwestern.edu., Logsdon JL; Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA m-wasielewski@northwestern.edu., Qi Y; Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA m-wasielewski@northwestern.edu., Miller SA; Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA m-wasielewski@northwestern.edu., Tempelaar R; Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA m-wasielewski@northwestern.edu., Young RM; Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA m-wasielewski@northwestern.edu., Wasielewski MR; Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA m-wasielewski@northwestern.edu.
Jazyk: angličtina
Zdroj: Chemical science [Chem Sci] 2020 Aug 13; Vol. 11 (35), pp. 9532-9541. Date of Electronic Publication: 2020 Aug 13.
DOI: 10.1039/d0sc03301d
Abstrakt: Organic donor-acceptor (D-A) co-crystals have attracted much interest due to their important optical and electronic properties. Co-crystals having ⋯DADA⋯ π-stacked morphologies are especially interesting because photoexcitation produces a charge-transfer (CT) exciton, D˙ + -A˙ - , between adjacent D-A molecules. Although several studies have reported on the steady-state optical properties of this type of CT exciton, very few have measured the dynamics of its formation and decay in a single D-A co-crystal. We have co-crystallized a peri -xanthenoxanthene ( PXX ) donor with a N , N -bis(3-pentyl)-2,5,8,11-tetraphenylperylene-3,4:9,10-bis(dicarboximide) ( Ph4PDI ) acceptor to give an orthorhombic PXX - Ph4PDI ⋯DADA⋯ π-stacked co-crystal with a CT transition dipole moment that is perpendicular to the transition moments for S n ← S 0 excitation of PXX and Ph4PDI . Using polarized, broadband, femtosecond pump-probe microscopy, we have determined that selective photoexcitation of Ph4PDI in the single co-crystal results in CT exciton formation within the 300 fs instrument response time. At early times (0.3 ≤ t ≤ 500 ps), the CT excitons decay with a t -1/2 dependence, which is attributed to CT biexciton annihilation within the one-dimensional ⋯DADA⋯ π-stacks producing high-energy, long-lived (>8 ns) electron-hole pairs in the crystal. These energetic charge carriers may prove useful in applications ranging from photovoltaics and opto-electronics to photocatalysis.
Competing Interests: There are no conflicts to declare.
(This journal is © The Royal Society of Chemistry.)
Databáze: MEDLINE
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