An efficient and simple method for synthesizing all-conjugated diblock copolymers is reported, using the Stillepolycondensation of A−A (dithienosilole) and B−B (diketopyrrolopyrrole) monomers with a macro end-capping agent P3HT.Diblock and triblock copolymers were produced with a molar composition that was tuned via the macromonomer molar mass andfeed ratio. The molar mass and topology of the macromolecules obtained are discussed on the basis of the Carothers equation,conversion, and monomer ratio. Spectrophotometry and cyclic voltammetry were used to highlight the complementarity of blockabsorption and the donor−acceptor nature of copolymers. Finally, integration in solar cells has been successfully performed withefficiencies reaching 2%. Performances of the devices were molar composition dependent and revealed that the performanceenhancement provided by low-band-gap block absorption was balanced by the copolymer nanostructuration that shrinks the chargecollection at electrodes.