| dc.description.abstract | Dye-sensitized solar cells (DSCs) are the new-generation photovoltaic technologies, which have the advantages such as easy fabrication and low cost. In this study, we optimized the device fabrication conditions to improve power conversion efficiency (PCE) for our new ruthenium complexes sensitizers coded CYC-37 and CYC-39, respectively. In addition to utilizing chenodeoxycholic acid (CDCA) as a co-adsorbent for decreasing dye aggregation and reducing uncovered surface of TiO2 film, we changed the electrolyte composition based on iodide/triiodide (I-/I3-) redox couple, including different imidazolium iodide (BMII, DMII and EMII) as well as different concentration of LiI and tBP. Moreover, we optimized TiO2 thickness, adsorption tempareture and time, as well as the co-sensitization based on CYC-37 and an organic dye (SBT6-A). The best device sensitized with CYC-39 reaches Jsc, Voc and FF of 18.92 mA cm-2, 0.694 V and 70.56%, respectively, yielding PCE of 9.27%. Another device based on CYC-37 also provide the same PCE (the corresponding Jsc, Voc and FF is 18.74 mA cm-2, 0.688 V and 71.84%, respectively), both superior to that of Black dye (8.93%). In the co-sensitized device based on CYC-37 and SBT6-A, the latter dye increases device response in the region of 400 ~ 550 nm, yielding the highest Jsc of 20.27 mA cm-2 and PCE of 9.76%. The corresponding electron diffusion coefficient (D) estimated from the intensity- modulated photocurrent spectroscopy (IMPS) is also the highest among the devices sensitized with single dye molecule. | en_US |