We report a straightforward synthesis toward conjugated rod-spacer-rod type block copolymer with both poly(2,7-carbazoles) (PCz) electron-donor (D) and perylene tetracarboxydiimide (PDI) electron-acceptor blocks. Two chromophores are covalently connected through sebacate units as saturated spacer. The resulting donor-spacer-acceptor type block copolymer (PCz-S-PDI) can be favorable way to limit charge recombination between donor-acceptor interfaces and to control the scale length of nanostructure formation. The PCz-S-PDI was used to produce a solar cell with the power conversion efficiency of 0.004%.