Abstract
The Ru(II) polypyridine complexes SA22 and SA25 consisting of anchoring and light harvesting moieties and possessing broad light absorption spectra were used to fabricate and optimize dye-sensitized solar cells (DSSCs). The highly efficient Z960 electrolyte was used as redox-mediator, and the J-V characteristics and incident photon-to-current conversion efficiency (IPCE) data were measured. The solar cells based on these dyes and electrolyte yielded power conversion efficiencies (PCE) of 7% using SA22 and 5% with SA25. The higher-performance sensitizer SA22 was selected to build solar-cell devices, using either the high-thermal-stability Z946 electrolyte or a gel-electrolyte composed of Z946 electrolyte and 2wt% low-molecular-mass organogelator (LMOG) NME-5. The quasi-solid-state electrolyte produced a DSSC with a PCE of 4.7%, whereas that made using Z946 showed 5% efficiency. The quasi-solid-state DSSC was sealed and a stability study was performed using accelerated thermal aging conditions at 70 degrees C for 7days, by which the cell parameters (including PCE, J(sc), V-oc, and FF) retained more than 90% of their original values.