A Perylene-Based Polycyclic Aromatic Hydrocarbon Electron Donor for a Highly Efficient Solar Cell Dye.

The continuing efforts to develop novel polycyclic aromatic hydrocarbons and exploit them as building blocks to create organic donor-acceptor (D-A) dyes with impressive excited-state features should offer an excellent means by which to improve the power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs). To this end, a nonacyclic aromatic hydrocarbon, N-annulated benzoindenopentaphene (NBIP) was tethered with multiple solubilizing groups, including NBIPs with one 2-hexyldecyl, with one 2-hexyldecyloxy, and with four 4-hexylphenyl substituents. The side- and end-chain-functionalized NBIPs can be conveniently prepared in excellent yield, and further cross-coupled with 4-(7-ethynylbenzo[c][1,2,5]thiadiazol-4-yl)benzoic acid to afford a metal-free D-A dye, which achieves a high power conversion efficiency of 12.6 % under AM1.5G illumination in DSSCs without need for any coadsorbent.