A new donor/acceptor (D–A) spiro dye (SCPDT1) featuring two bithiophene units, connected through an sp3-hybridized carbon atom, was prepared by a multistep synthetic sequence involving the convenient assembly of the spiro system under mild catalytic conditions. The photocurrent spectrum of dye-sensitized solar cells incorporating SCPDT1 covers the spectral region ranging from 350 to 700 nm and reaches a wide maximum of∼ 80% in the ...