Co-adsorption of complementary pyridyl and carboxylic acid based dyes in dye-sensitized solar cells.

Abstract

The harnessing of sunlight to convert it to electrical energy is the basic idea of a solar cell, and has been a subject of interest to scientists for decades. One of the so-called third generation solar cells, is what is commonly known as the dye sensitized solar cell (DSSC), is based on a thin film of mesoporous TiO2 that is sensitized with either an organic or inorganic dye. Our line of research has focused mainly on the synthesis of dyes and the study of the structure-function relationship and their effects on the DSSC’s efficiency. Many attempts were made to improve the performance of organic based DSSCs, by either changing the anchoring group of the dye, the dye molecular structure (such as with different middle electron-acceptor groups), electrolyte system, counter electrode, etc. We are currently working on the synthesis of three novel organic dyes of the form donor-π-acceptor-π- with a pyridine moiety as the terminal anchoring group. The middle acceptor group will be varied, in order to shift the dyes’ absorption more towards the red depending on its electron-accepting ability and hence increase their light harvesting efficiencies. In addition, we will study the effect of co-sensitization of the above mentioned dyes with complementary carboxylic-acid based ones, where both classes of dyes adsorb at different sites of titania, in order to enhance the overall efficiencies of the cells in particular the photo-current.