High‐Performance Aqueous/Organic Dye‐Sensitized Solar Cells Based on Sensitizers Containing Triethylene Oxide Methyl Ether

Metal-free dyes (EO1 to EO4) containing the hydrophilic triethylene oxide methyl ether (TEOME) unit in the spacer have been synthesized and used in dye-sensitized solar cells (DSSCs). Efficient lithium-ion trapping by TEOME results in improved open-circuit voltage (VOC), leading to excellent conversion efficiency of the cells, ranging from 9.02 to 9.98 % with I−/I3− electrolyte in acetonitrile under AM 1.5 illumination. The TEOME unit also enhances the wettability of the dye molecules for application in aqueous-based DSSCs. Aqueous-based DSSCs with a dual TEMPO/iodide electrolyte exhibit high VOC values (0.80–0.88 V) and very promising cell performances of up to 5.97 %.