Wavelength Conversion Lanthanide(III)-cored Complex for Highly Efficient Dye-sensitized Solar Cells

Abstract

Lanthanide(III)-cored complex as a wavelength conversion material has been successfully designed and synthesized for highly efficient dye-sensitized solar cells, for the first time, since light with a short wavelength has not been effectively used for generating electric power owing to the limited absorption of these DSSCs in the UV region. A black dye (BD) was chosen and used as a sensitizer, because BD has a relatively weak light absorption at shorter wavelengths. The overall conversion efficiency of the BD/WCM device was remarkably increased, even with the relatively small amount of WCM added to the device. The enhancement in V-oc by WCM, like DCA, could be correlated with the suppression of electron recombination between the injected electrons and I-3(-) ions. Furthermore, the short-circuit current density was significantly increased by WCM with a strong UV light-harvesting effect. The energy transfer from the Eu(III)-cored complex to the TiO2 film occurred via the dye, so the number of electrons injected into the TiO2 surface increased, i.e., the short-circuit current density was increased. As a result, BD/WCM-sensitized solar cells exhibit superior device performance with the enhanced conversion efficiency by a factor of 1.22 under AM 1.5 sunlight: The photovoltaic performance of the BD/WCM-based DSSC exhibited remarkably high values, J(sc) of 17.72 mA/cm(2), V-oc of 720 mV, and a conversion efficiency of 9.28% at 100 mW cm(-2), compared to a standard DSSC with J(sc) of 15.53 mA/cm(2), V-oc of 689 mV, and a conversion efficiency of 7.58% at 100 mW cm(-2). Therefore, the Eu(III)-cored complex is a promising candidate as a new wavelength conversion coadsorbent for highly efficient dye-sensitized solar cells to improve UV light harvesting through energy transfer processes. The abstract should be a single paragraph which summaries the content of the article