| dc.description.abstract | In dye-sensitized solar cells (DSCs), photosensitizer is the most important component affecting significantly power conversion efficiency (PCE) and stability of the devices. Among numerous photosensitizers, ruthenium (Ru) complexes sensitizers are very promising to enhance further the performance of devices, due to their metal–ligand charge transfer (MLCT) transition that extends into the red and near-infrared region. In this research, we designed and synthesized two new ruthenium complexes, coded CYC-36 and CYC-41, respectively. Our designing concept is based on Black dye (N749) which contains a terpyridine anchoring ligand. We replaced one carboxyl group at the fourth position of terpyridine ligand with pyrrole and thieno[3,2‑b]pyrrole, respectively. The maximum absorption wavelength (max) of CYC-41 is 615 nm red-shifted over 15 nm than that of Black dye. The molar absorption coefficient of CYC-41 (8800 M-1 cm-1) is also higher than of Black dye (7500 M-1 cm-1). IPCE results show the devices sensitized with CYC-36 and CYC-41 in conjunction with an iodide-based electrolyte can convert more blue and red light photons into electricity than that of Black dye. Moreover, when the thickness of TiO2 is fune-tuned to 45 µm and 25 µm, the Jsc of devices based on CYC-36 and CYC-41 reaches 17.34 mA cm-2 and 17.64 mA cm-2, yielding respectively the PCE of 8.00% and 7.82%. Under the same conditions, the performance of Black dye-based cell is 8.93% and 8.88%, respectively. In addition to the design of two new dyes, we compared systematically the properties and the device characteristics for the three dyes as well as CYC-37 and CYC-39 we developed previously to provide more clues of designing highly efficient ruthenium photosensitizers. | en_US |