A novel D–A-π-A organic sensitizer containing a diketopyrrolopyrrole unit with a branched alkyl chain for highly efficient and stable dye-sensitized solar cells

A novel D-A-π-A type organic dye (YCD01) incorporating a diketopyrrolopyrrole unit with a branched alkyl chain was synthesized for dye-sensitized solar cells. YCD01 showed a high conversion efficiency of 7.43% (AM 1.5, 100 mW cm(-2)) with a J(sc) of 13.40 mA cm(-2), a V(oc) of 0.76 V, a FF of 0.73 and an excellent stability.