Triplet-Triplet Annihilation Based Energy Upconversion Mechanism: Cyanine7 Dye Doped with Super Yellow and Rubrene Hosts

Year 2020, Volume: 24 Issue: 1, 55 - 59, 01.02.2020

Murat Aydemir

https://doi.org/10.16984/saufenbilder.538797

Abstract

In this work, two case studies for
energy upconversion mechanisms are presented; one via two photon absorption and the other one via triplet fusion mechanism. These are strongly required
photophysical mechanisms in conjugated organic molecules, due to showing
ability to enhance the efficiency of organic electronic devices. During the
investigations, Cyanine7 (Cye7) molecule is used as a sensitizer and for the
host molecules rubrene and super yellow molecules are preferred due to their comparatively
close locally excited triplet energy levels. The results show that upconverted
delayed fluorescence arises from triplet-triplet annihilation mechanism in those
particular sensitizer-host systems which gives rise to enhance the internal
quantum efficiencies by populating the locally excited singlet states.
Consequentially, for the first time Cye7 (near infrared) dye is used as a
sensitizer in an energy upconversion experiment, and also two photon absorption
mechanism is reported in ppv based 'super yellow' polymer which has two photon
absorption cross-section at 780 nm

Keywords

Cyanine7 dye, delayed fluorescence, energy up-conversion, rubrene, super yellow

References

• Dr. Figen TÜRKSOY; TUBİTAK-MAM; email: [e-mail]
• Prof. Dr. Canan VARLIKLI; İYTE; email: [e-mail]
• Prof. Dr. Ali ÇIRPAN; ODTÜ; email: [e-mail]