Title:Is it Photodegradation or other Electronic Mechanisms Responsible for
Photoluminescence Quenching under Nonenvironmental Conditions in
Poly(3-octyltiophene) Electrochemically Synthesised?
Volume: 2
Issue: 6
Author(s): Júlio Goulart dos Santos, Lenner Santos Rodrigues, Romildo Jerônimo Ramos, Alexandre Marletta and Eralci Moreira Therézio*
Affiliation:
- Institute of Physics, Federal University of Mato Grosso, Cuiabá, Brazil
Keywords:
P3OT, photodegradation, photoluminescence, energy transfer, quenching luminescence, electrochemically synthesis, photophysics.
Abstract:
Aims: This work investigates the photoluminescence properties of poly(3-
octylthiophene), namely P3OT films, under excitation power and time light expositions. When
exposed to monochromatic illumination, the degradation mechanism of P3OT films is precise in
environmental conditions. However, in some environmental controlled or non-environmental conditions,
the quenching luminescence of P3OT subject to monochromatic light excitation is not fully
understood. In this context, it is necessary to understand what causes quenching luminescence
of P3OT films under environmental conditions.
Methods: The P3OT was synthesized by chronocoulometry, using tetraethylammonium tetrafluoroborate
and lithium perchlorate as supporting electrolytes, and after it is deposited on a conductive
substrate of fluoride-doped tin oxide (FTO). The films were synthesized and maintained
under an argon atmosphere, and their thickness is dependent on the charge. The characterisation
was achieved by applying techniques like UV-Vis absorption spectroscopy, photoluminescence,
and emission ellipsometry.
Results: The UV-Vis absorption measurements demonstrated a different interaction of polymer/
dopant due to the polaronic band. The results showed that photoluminescence quenching with
time is a behaviour caused by energy transfer between quinone chains and pristine chains of the
P3OT. The polarised emission measurements corroborate the hypothesis of energy transfer between
chains. The emission ellipsometry technique was used to understand energy transfer processes
and other properties. The self-absorption phenomenon and integrated PL investigation of
the P3OT emission elucidated the mechanism involved in the observed properties.
Conclusion: Besides that, the results show that photoluminescence quenching happens in nonenvironmental
and environmental conditions, corroborating the hypothesis that PL quenching occurs
because self-absorption phenomena influence the energy transfer mechanism.