Near IR to Red Up-Conversion in Tetracene/Pentacene Host/Guest Cocrystals Enhanced by Energy Transfer from Host to Guest
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- 作者：Teresa Gatti ; Luigi Brambilla ; Matteo Tommasini ; Francesca Villafiorita-Monteleone ; Chiara Botta ; Valerio Sarritzu ; Andrea Mura ; Giovanni Bongiovanni ; Mirella Del Zoppo
- 刊名：Journal of Physical Chemistry C
- 出版年：2015
- 出版时间：August 6, 2015
- 年：2015
- 卷：119
- 期：31
- 页码：17495-17501
- 全文大小：401K
- ISSN：1932-7455
文摘
Solid-state materials with up-conversion activity at low power excitation are highly desirable for several optoelectronic applications. In this work we show that a host/guest cocrystal of tetracene/pentacene (Tc/Pc) exhibits a near-infrared (NIR) excited up-conversion process. F枚rster resonant energy transfer (FRET) from Tc to Pc is enhanced by NIR excitation with respect to visible excitation. A triplet鈥搕riplet annihilation mechanism activated by the pentacene molecules acting as traps in the host crystal is proposed and confirmed by time-resolved fluorescence spectra. TDDFT calculations on model molecular clusters support this hypothesis, highlighting the existence of strong excitonic interactions which is a necessary prerequisite for good transport of photogenerated excitons in Pc-doped Tc crystals.