title: A triazine di(carboxy)porphyrin dyad versus a triazine di(carboxy)porphyrin triad for sensitizers in DSSCs.
abstract: Two porphyrin-chromophores, i.e. triad PorZn-(PorCOOH)(2)-(piper)2 (GZ-T1) and dyad (PorZn)(2)-NMe2 (GZ-T1), have been synthesized and their photophysical and electrochemical properties have been investigated. The optical properties together with the appropriate electronic energy levels, i.e. the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels, revealed that both porphyrin assemblies can function as sensitizers for dye sensitized solar cells (DSSCs). The and -based DSSCs have been prepared and studied using 20 mM CDCA as coadsorbent and were found to exhibit an overall power conversion efficiency (PCE) of 5.88% and 4.56%, respectively (under an illumination intensity of 100 mW cm(-2) with TiO(2) films of 12 μm). The higher PCE of the -sensitized DSSC, as revealed from the current-voltage characteristic under illumination and the incident photon to current conversion efficiency (IPCE) spectra of the two DSSCs, is mainly attributed to its enhanced short circuit current (J(sc)), although both the open circuit voltage (V(oc)) and the fill factor are improved too. The electrochemical impedance spectra (EIS) demonstrated a shorter electron transport time, longer electron lifetime and higher charge recombination resistance for the DSSC sensitized with the dye as well as a larger dye loading onto the TiO(2) surface.
authors.affiliation: Department of Chemistry, Laboratory of Bioinorganic Chemistry, University of Crete, Voutes Campus, P.O. Box 2208, 71003, Heraklion, Crete, Greece. coutsole@chemistry.uoc.gr.
authors.forename: G E
authors.initials: GE
authors.lastname: Zervaki
authors.forename: Vasilitsa
authors.initials: V
authors.lastname: Tsaka
authors.forename: Alexandra
authors.initials: A
authors.lastname: Vatikioti
authors.forename: Irene
authors.initials: I
authors.lastname: Georgakaki
authors.forename: Vasilis
authors.initials: V
authors.lastname: Nikolaou
authors.forename: G D
authors.initials: GD
authors.lastname: Sharma
authors.forename: A G
authors.initials: AG
authors.lastname: Coutsolelos
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D011211:Electric Power Supplies; D004579:Electron Transport; D008027:Light; D008958:Models, Molecular; D011166:Porphyrins / Q000737:chemistry*; D012993:Solar Energy; D014227:Triazines / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D004396:Coloring Agents; D011166:Porphyrins; D014227:Triazines