YD2: A Green Porphyrin Dye for Dye-sensitized Solar Cells

YD2 is a green zinc-centered porphyrin dye used as a sensitizer for dye-sensitized solar cells (DSSCs).¹⁾ Although ruthenium-based dyes such as N719 dye and N749 black dye are well known as efficient sensitizers, ruthenium-free sensitizers including porphyrin dyes have also been developed as they do not need to contain any noble metals, which can reduce material cost. YD2 is a promising material whose power conversion efficiencies attain up to 11% in a device including reflecting particles, and 8.8% in a device without the reflecting layer.²⁾ The material shows a wide bathochromic-shifted Soret band and Q band due to its electron-donating diphenylamino moiety, and an electron-withdrawing carboxyphenylethynyl at the meso-positions of the porphyrin ring.