High spectral response heteroleptic ruthenium (II) complexes as sensitizers for dye sensitized solar cells

• Published in: Journal of chemical sciences (Bangalore, India) India), 2011, Vol.123 (1), p.37-46
• Main Authors: CHANDRASEKHARAM, M, SRINIVASARAO, C, SURESH, T, REDDY, M ANIL, RAGHAVENDER, M, RAJKUMAR, G, SRINIVASU, M, REDDY, P YELLA
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry/Food Science
• ISSN: 0974-3626; 0973-7103
• DOI: 10.1007/s12039-011-0066-7

Heteroleptic ruthenium(II) bipyridyl complex, cis -Ru(II)(4,4’- bis (4- tert -butylstyryl)-2,2’-bipyridyl) (4,4’-dicarboxy-2,2’-bipyridyl) (NCS 2 ) ( H 112) was synthesized and characterized by 1 H-NMR, MASS, Spectrofluorometer and UV-Vis spectroscopes. The photo-voltaic performance of the sensitizer was evaluated in Dye Sensitized Solar Cell (DSSC) under irradiation of AM 1·5G solar light and the photovoltaic characteristics were compared with those of reference cells of HRS 1 and N 719 fabricated under comparable conditions. Compared to N 719, H 112 sensitizer showed enhanced molar extinction coefficient and relatively better monochromatic incident photon-to-current conversion efficiency (IPCE) across the spectral range of 400 to 800nm with solar energy-to-electrical conversion efficiency ( η ) of 2·43% [open circuit photovoltage ( V OC )=0·631V, short-circuit photocurrent density (J SC )=8·96mA/cm 2 , fill factor (ff)=0·430], while η values of 2·51% ( V OC =0·651V, J SC =9·41 mA/cm 2 , ff=0·410) and 2·74% ( V OC =0·705V, J SC =8·62mA/cm 2 , ff=0·455) were obtained for HRS 1 and N 719 sensitized solar cells respectively. The introduction of 4,4’- bis (4- tert -butylstyryl) moieties on one of the bipyridine moieties of N 719 complex shows higher light absorption abilities, IPCE and J SC . Graphical Abstract A new Heteroleptic ruthenium(II) bipyridyl complex, cis -Ru(II) (4,4'- bis (4- tert -butylstyryl)-2,2'-bipyridyl) (4,4’-dicarboxy-2,2’-bipyridyl) (NCS 2 ) (H112) was synthesized and the photo-voltaic performance of the sensitizer was evaluated in Dye Sensitized Solar Cell ( DSSC ) under irradiation of AM 1.5G solar light. The introduction of 4,4'- bis (4- tert -butylstyryl) moieties on one of the bipyridine moieties of the ruthenium (II) complex enhances light absorption abilities, IPCE and J SC .