Improving the photovoltaic performance by employing alkyl chains perpendicular to the π-conjugated plane of an organic dye in dye-sensitized solar cells

We demonstrate that employing long alkyl chains perpendicular to the pi-conjugated plane of the backbone is a promising strategy to construct efficient organic sensitizers for dye-sensitized solar cells (DSSCs) with efficient photovoltaic performance. The perpendicular alkyl chains have been suggested as superior alternatives to parallel alkyl chains for preventing intermolecular interactions in D-pi-A dyes, and therefore co-adsorption with deoxycholic acid (DCA) can be avoided. DSSCs employing iodine/iodide electrolytes and an organic dye LJ-8 with long alkyl chains perpendicular to its pi-conjugated plane produced a high photovoltage of 0.801 V and a high conversion efficiency over 8%.