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

Abstract

We demonstrate that employing long alkyl chains perpendicular to the π-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–π–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 π-conjugated plane produced a high photovoltage of 0.801 V and a high conversion efficiency over 8%.