Porphyrin Cosensitization for a Photovoltaic Efficiency of 11.5%: A Record for Non-Ruthenium Solar Cells Based on Iodine Electrolyte

Dye-sensitized solar cells (DSSCs) are promising for utilizing solar energy. To achieve high efficiencies, it is vital to synergistically improve the photocurrent (J(sc)) and the photovoltage (V-oc). In this respect, conjugation framework extension and cosensitization are effective for improving the absorption and the J(sc), which, however, is usually accompanied by undesirably decreased V-oc. Herein, based on a rationally optimized porphyrin dye, we develop a targeted coadsorption/cosensitization approach for systematically improving the V-oc from 645 to 727, 746, and 760 mV, with synergistical J(sc) enhancement from 18.83 to 20.33 mA cm(-2). Thus, the efficiency has been dramatically enhanced to 11.5%, which keeps the record for nonruthenium DSSCs using the I-2/I-3(-) electrolyte. These results compose an alternative approach for developing highly efficient DSSCs with relatively high V-oc using traditional iodine electrolyte.