Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Homo‐ and Heterodimeric Dyes for Dye‐Sensitized Solar Cells: Panchromatic Light Absorption and Modulated Open Circuit Potential

Homo‐ and Heterodimeric Dyes for Dye‐Sensitized Solar Cells: Panchromatic Light Absorption and... The design of dyes for panchromatic light absorption has attracted much attention in the field of dye‐sensitized solar cells (DSSCs). An approach to enhance panchromatic light absorption utilizes mixtures of complementary light‐absorbing dyes as well as dyes with specific anchoring groups that facilitate interfacial charge transfer with TiO2. Dipole‐dipole interactions between the dye molecules on the surface broaden the spectrum, which results in decreased DSSC device performance. However, controlled aggregation of dyes results in broadening the spectral profile along with enhanced photocurrent generation. To control the dye‐dye interaction, dimeric dyes with different dipole lengths D1‐Dsq, Dsq‐Dsqwere systematically designed and synthesized. The photophysical and electrochemical properties were evaluated and the EHOMO and ELUMO levels were determined; these energy levels determines the electron injection from ELUMO of the dye to ECB of TiO2 and regeneration of oxidized dye by the electrolyte, respectively. The absorption spectra of Dsq‐Dsq, D1‐Dsq were broadened in solution compared to model dye Dsq; this indicates that the dye‐dye interaction is prominent in solution. In D1‐Dsq excitation energy transfer between photoexcited D1 and Dsq was explained by using Förster resonance energy transfer (FRET). The homodimeric dye showed a device performace of 2.8 % (Voc 0.607, Jsc 6.62 mA/cm2, ff 69.3 %),whereas the heterodimeric dye D1‐Dsq showed a device performance of 3.9 % (Voc 0.652 V, Jsc 8.89 mA/cm2, ff 68.8 %). The increased photocurrent for D1‐Dsqis due to the panchromatic IPCE response compared to Dsq‐Dsq. The increased Vocis due to the effective passivation of the TiO2 surface by the spirolinker, and the effective dipole moment that shifts the conduction band on TiO2. Hence, the open circuit potential, Voc, for the devices prepared from Dsq, D1‐Dsq and Dsq‐Dsqwere systematically modulated by controlling the intermolecular π‐π and intramolecular dipole‐dipole interactions of the dimeric dyes. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png ChemPlusChem Wiley

Homo‐ and Heterodimeric Dyes for Dye‐Sensitized Solar Cells: Panchromatic Light Absorption and Modulated Open Circuit Potential

Loading next page...
 
/lp/wiley/homo-and-heterodimeric-dyes-for-dye-sensitized-solar-cells-BxWqbcnkZa

References (72)

Publisher
Wiley
Copyright
© 2018 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim
ISSN
2192-6506
eISSN
2192-6506
DOI
10.1002/cplu.201800450
Publisher site
See Article on Publisher Site

Abstract

The design of dyes for panchromatic light absorption has attracted much attention in the field of dye‐sensitized solar cells (DSSCs). An approach to enhance panchromatic light absorption utilizes mixtures of complementary light‐absorbing dyes as well as dyes with specific anchoring groups that facilitate interfacial charge transfer with TiO2. Dipole‐dipole interactions between the dye molecules on the surface broaden the spectrum, which results in decreased DSSC device performance. However, controlled aggregation of dyes results in broadening the spectral profile along with enhanced photocurrent generation. To control the dye‐dye interaction, dimeric dyes with different dipole lengths D1‐Dsq, Dsq‐Dsqwere systematically designed and synthesized. The photophysical and electrochemical properties were evaluated and the EHOMO and ELUMO levels were determined; these energy levels determines the electron injection from ELUMO of the dye to ECB of TiO2 and regeneration of oxidized dye by the electrolyte, respectively. The absorption spectra of Dsq‐Dsq, D1‐Dsq were broadened in solution compared to model dye Dsq; this indicates that the dye‐dye interaction is prominent in solution. In D1‐Dsq excitation energy transfer between photoexcited D1 and Dsq was explained by using Förster resonance energy transfer (FRET). The homodimeric dye showed a device performace of 2.8 % (Voc 0.607, Jsc 6.62 mA/cm2, ff 69.3 %),whereas the heterodimeric dye D1‐Dsq showed a device performance of 3.9 % (Voc 0.652 V, Jsc 8.89 mA/cm2, ff 68.8 %). The increased photocurrent for D1‐Dsqis due to the panchromatic IPCE response compared to Dsq‐Dsq. The increased Vocis due to the effective passivation of the TiO2 surface by the spirolinker, and the effective dipole moment that shifts the conduction band on TiO2. Hence, the open circuit potential, Voc, for the devices prepared from Dsq, D1‐Dsq and Dsq‐Dsqwere systematically modulated by controlling the intermolecular π‐π and intramolecular dipole‐dipole interactions of the dimeric dyes.

Journal

ChemPlusChemWiley

Published: Nov 1, 2018

Keywords: ; ; ; ;

There are no references for this article.