Molecular Design of Sensitizers for Dye-Sensitized Solar Cells

Abstract

In this chapter, we focus on the detailed molecular design of sensitizers, such as metal complexes, porphyrins, and metal-free organic dyes, for dye-sensitized solar cells (DSSCs), which is one of promising unconventional solar cells. Over the last decade, interest in DSSCs has increased because these unconventional solar cells exhibit high solar-energy-to-electricity conversion efficiencies of up to 11% and have the potential for low-cost production. The main components of a DSSC are a nanocrystalline oxide semiconductor electrode, a sensitizer, an electrolyte containing redox ions, and a counter electrode. The sensitizer determines the photoresponse range of the solar cell and mediates the primary steps of photon absorption and the subsequent electron-transfer process. The relationship between the solar-cell performance of DSSCs and the properties of sensitizer in terms of the structures, photophysical, photoelectrochemical, and electrochemical properties are discussed.