Seven flavylium salt dyes were employed for the first time as sensitizers for dye-sensitized solar cells (DSSCs). The theoretical and experimental wavelengths of the maximum absorbances, the HOMO and LUMO energy levels, the coefficients, the oscillator strengths and the dipole moments are calculated for these synthetic dyes. The introduction of a donor group in the flavylium molecular structure was investigated. Photophysical and photoelectrochemical measurements showed that some of these synthetic analogues of anthocyanins are very promising for DSSC applications. The best performance was obtained by a DSSC based on the novel compound 7-(N,N-diethylamino)-3',4'-dihydroxyflavylium which produced a 2.15% solar energy-to-electricity conversion efficiency, under AM 1.5 irradiation (100 mW cm(-2)) with a short-circuit current density (J(sc)) of 12.0 mA cm(-2), a fill factor of 0.5 and an open-circuit voltage (V-oc) of 0.355 V; its incident photocurrent efficiency of 51% at the peak of the visible absorption band of the dye is remarkable. Our results demonstrated that the substitution of a hydroxylic group with a diethylamine unit in position 7 of ring A of the flavylium backbone expanded the pi-conjugation in the dye and thus resulted in a higher absorption in the visible region and is advantageous for effective electron injection from the dye into the conduction band of TiO2.
ISI Document Delivery No.: 131WETimes Cited: 3
Cited Reference Count: 57
Calogero, Giuseppe Sinopoli, Alessandro Citro, Ilaria Di Marco, Gaetano Petrov, Vesselin Diniz, Ana M. Jorge Parola, A. Pina, Fernando
Pina, Fernando/C-8161-2011; Parola, A. Jorge/F-4048-2010; Caparica, cqfb_staff/H-2611-2013; REQUIMTE, AL/H-9106-2013
Parola, A. Jorge/0000-0002-1333-9076;
"EFOR" Project; CNR; Project "SAGRO"; Regione Siciliana (Assessorato Regionale Attivita Produttive progetti PO FESR linea d'intervento) [4.1.1.1]; Fundacao para a Ciencia e Tecnologia through the National Portuguese NMR Network [C/EQB/LA0006/2011, PTDC/QUI-QUI/119932/2010]; Programma Operativo Nazionale Ricerca e Competitivita [PON 01_02257 FOTORIDUCO2]
This research was supported by "EFOR" Project financed by CNR and by Project "SAGRO" financed by Regione Siciliana (Assessorato Regionale Attivita Produttive progetti PO FESR 2007/2013 linea d'intervento 4.1.1.1). This work was also supported by Fundacao para a Ciencia e Tecnologia through the National Portuguese NMR Network, grant PEst-C/EQB/LA0006/2011 and project PTDC-QUI-QUI/119932/2010. Furthermore we acknowledge Programma Operativo Nazionale Ricerca e Competitivita 2007-2013-project PON 01_02257 FOTORIDUCO2. We gratefully acknowledge Roberto Caruso and Giuseppe Lupo (IPCF_CNR) for their technical assistance for device assembly.
Royal soc chemistry
Cambridge