Title:Modification of Optical and Electrical Characteristics of PEDOT:PSS by Umbelliferone Addition: Optical and Electrical Characterization of Umbelliferone Doped PEDOT:PSS for Photovoltaic Applications
Volume: 14
Issue: 5
Author(s): Leonardo Schneider Berlim, Fabiano Thomazi, Ezequiel Burkarter, Claudia Eliana Bruno Marino, Cyro Ketzer Saul , Amando Siuiti Ito and Cesar Augusto Dartora*
Affiliation:
- Programa de Pos-Graduacao em Engenharia e Ciencia dos Materiais, Universidade Federal do Parana, Centro Politecnico, Jardim das Americas, 81531-980 Curitiba, Parana,Brazil
Keywords:
Photovoltaic, umbelliferone, charge transfer, PEDOT:PSS, absorption, fluorescence, lifetime, cyclic voltammetry.
Abstract: Background: In the last 40 years, scientific efforts were focused on the efficiency improvement
in organic photovoltaic devices. Bleaching agents were used to absorb UV light and
convert it into lower energy radiation appear as potential candidates for further improvements. The
present contribution investigated the effect of adding umbelliferone to poly(3,4-ethylenedioxythiophene)
polystyrene sulfonate (PEDOT:PSS) on its optical and electrical properties.
Methods: Characterizations were performed under various umbelliferone concentrations. Fluorescence
decay lifetimes were obtained using a MicroTime 200 system (PicoQuant). The UV–vis absorption
spectra were obtained with a GE Healthcare Ultrospec 2100 pro Spectrometer. The electrical
conductivity measurements as a function of temperature using a cryostat model ARS
CS202AE-DMX-1AL.
Results: The absorbance increases around 325 nm and decreases in the near infrared s the umbelliferone
concentration is increased. It also decreases the absorption in the visible spectrum, concomitantly
with a significant increase in the UV region. The electrical conductivity for the umbelliferone
doped PEDOT:PSS films display an increase with increasing temperature, but does not follow
a linear behavior with the increase of umbelliferone concentration in the films.
Conclusion: It was shown that the absorbance displays a redshift in doped samples, while photoluminescence
experiments demonstrated that UV light is converted to the visible spectrum more
efficiently, which is a desirable feature for photovoltaic devices. Also, the electrical conductivity of
PEDOT:PSS is increased for moderate umbelliferone concentrations.