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 Voc by WCM, like DCA, could be correlated with the suppression of electron recombination between the injected electrons and I3 - 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, Jsc of 17.72 mA/cm2, Voc of 720 mV, and a conversion efficiency of 9.28% at 100 mW cm-2, compared to a standard DSSC with Jsc of 15.53 mA/cm2, Voc 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 dyesensitized 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.