| dc.description.abstract | Dye-sensitized solar cells (DSCs) have attracted significant attention due to their unique working mechanism, diverse materials, low manufacturing costs, and good efficiency. Bipyridyl ruthenium (Ru)-based sensitizers have received considerable attention for attending high efficiency and stability of the corresponding DSCs. However, to date, their development has not effectively increased the near-infrared light absorption capacity. To breakthrough this limitation, two new bipyridyl Ru complexes (CYC-53 and CYC-55) are designed and synthesized. They have the heterocycles to simultaneously extend the conjugation length of both ancillary and anchoring ligands. Additionally, for the first time, selenophene and thienothiophene moieties are introduced in the anchoring ligands to extent their conjugate length. Compared with CYC-21 (747 nm) using thiophene in the anchoring ligand, CYC-53 and CYC-55 in DMF exhibit a red-shifted (by 19 nm and 14 nm, respectively), and increased absorption intensity. Moreover, all of the three complexes have the same HOMO energy level of +0.84 V (vs. NHE). LUMO energy levels for CYC-53 (-0.78 V vs. NHE) and CYC-55 (-0.79 V vs. NHE) are lower than that of CYC-21 (-0.82 V vs. NHE). Both of CYC-53 and CYC-55 dyed DSCs exhibit higher Jsc values than that based on CYC-21 (11.61 mA·cm-2). CYC-55-sensitized device achieves the highest efficiency of 6.85%. These results indicate that introducing heavy atoms and extending the conjugation length in the anchoring ligands of Ru complexes can effectively reduce the energy gap, broaden the absorption profile, and enhance the absorption coefficient, thereby improving the power conversion efficiency of the correspondry devices. | en_US |