A new terpyridine cobalt complex redox shuttle for dye-sensitized solar cells

• Published in: Inorganica Chimica Acta 2013-09, Vol.406, p.106-112
• Main Authors: Salvatori, Paolo, Marotta, Gabriele, Cinti, Antonio, Mosconi, Edoardo, Panigrahi, Mallika, Giribabu, Lingamallu, Nazeeruddin, Mohammad K., De Angelis, Filippo
• Format: Article
• Language: English
• Subjects: Chenodeoxycholic acid; Cobalt complex; Dye-sensitized solar cells (DSCs); Electrolyte; Terpyridine
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2013.07.003

A new cobalt-terpyridine redox shuttle based on a substituted terpyridine ligand, has been synthesized, characterized, computationally investigated and tested in photovoltaic devices. The new redox shuttle is compared to the reference [Co(bpy)3]2+/3+, analyzing the effect of different counterions. •Synthesis and characterization of a [Co(Cl-phenyl-terpy)2]2+/3+ redox couple.•Good agreement between experimental and calculated redox potentials.•Photovoltaic efficiency compared to the [Co(bpy)3]2+/3+ electrolyte with different counterions.•Improvement of the photovoltaic performances by using the CDCA additive. A new cobalt-terpyridine redox shuttle ([Co(Cl-phenyl-terpyridine)2]2+/3+) has been synthesized, characterized, computationally investigated and then tested in photovoltaic devices, in conjunction with the prototypical N719 and Z907 ruthenium dyes. Lower efficiencies compared to the reference [Co(bpy)3]2+/3+ redox couple were obtained, probably due to increased recombination processes. Improvements in the devices performances were obtained by using chenodeoxycholic acid as surface co-adsorbent and as an electrolyte additive. Moreover, to better rationalize the photovoltaic results, the effect of two different counterions (TFSI and PF6) has been investigated for the reference [Co(bpy)3]2+/3+ electrolyte, finding a reduced efficiency for the TFSI-based electrolyte.