Design, engineering, and evaluation of porphyrins for dye-sensitized solar cells

Abstract

Dye-sensitized solar cells (DSCs) have attracted worldwide attention due to their low cost and versatility. Porphyrins have broad and intense absorption in the visible region, versatility in tuning the molecular structure. Early porphyrin dyes are generally Β-functionalized meso-teraarylporphyrins. In the late 2000s, several groups began to pay their attention to meso-functionalized porphyrins. In 2010, the meso- functionalized porphyrin dye with donor-p-acceptor structure, achieved an efficiency of 11%. Since then, dozens of donor-p-acceptor porphyrin dyes with >10% efficiency have been reported. In 2014, the energy conversion efficiency of 13% was reached. However, some challenges still exist including inefficient photon capture in the regions around 520 nm and > 700 nm, severe aggregation because of porphyrin’s planar structure and rich π electrons, and poor long-term stability resulting from the weak binding capability of the anchoring group. In this chapter, we will provide readers the operation principles of DSC, an evolution of porphyrin dyes as the best candidates for DSCs, and challenges facing porphyrin dyes for DSCs. Different design strategies, synthetic protocols, as well as their photovoltaic performance of representative dyes will be discussed.