Abstracts Book - IMRC 2018

• SC4-O004
A HIGH OPEN CIRCUIT VOLTAGE DYE-SENSITIZED SOLAR CELL
BASED ON TiO2 IN THE BROOKITE PHASE
Dena Pourjafari 1 , David Reyes Coronado 2 , Alberto Gabriel Vega Poot 1 , Renan Andres Escalante
Quijano 1 , Gerko Oskam 1
1
CINVESTAV-Mérida, Física Aplicada, Mexico. 2 Universidad de Quintana Roo, Unidad Académica
Playa del Carmen, Mexico.
After the breakthrough report of O’Regan and Grätzel in 1991 1 introducing the
dye-sensitized solar cell (DSSCs), intensive investigation has been performed
worldwide to improve the performance. DSSCs are easy to fabricate using
inexpensive and reproducible techniques. In addition, their transparency,
lightweight and flexibility, and good performance at low light intensity and small
angles of incidence, make them a suitable candidate for indoor applications. 2
Although the most studied semiconductor used in DSSCs is TiO2 in the anatase
phase, brookite can be considered a promising alternative. However, there are
not many reports on brookite DSSCs due to the challenges in synthesis of phasepure
brookite nanomaterials. In this work, synthesis of brookite nanoparticles is
reported using amorphous titania as starting material which is converted to
brookite by a hydrothermal treatment. Brookite-based solar cells (0.5 cm 2 active
area) were fabricated using different dyes and redox pairs. Brookite electrodes
were sensibilized with N719 (ruthenium-based dye) and LEG4 (metalfree/organic
dye). Different electrolytes were used, containing I - /I3 - , Co +2 /Co +3
and Cu +1 /Cu 2+ complexes as redox mediators. The cell performance parameters
have been obtained and the internal cell parameters such as chemical
capacitance, charge transfer resistance, electron lifetime and electron diffusion
coefficient have been calculated from electrochemical impedance
electrochemical spectroscopy (EIS), intensity-modulated photocurrent
spectroscopy (IMPS) and intensity-modulated photovoltage spectroscopy
(IMVS). By comparing these parameters we explain which system is more
appropriate to achieve better performance under indoor lighting conditions.
References
1 B. O’Regan and M. Gratzel, Nature 353(6346), 737–740 (1991).
2 M. A. Green, Physica E 14(1–2), 65–70 (2002).