An article (100; 200), comprising: a first electrode (120; 220; 240); a second electrode (160; 240; 260); and a photoactive material (140; 230; 350) disposed between the first (120; 220; 240) and second electrodes (160; 240; 260), the photoactive material (140; 230; 350) comprising a polymer including a first comonomer repeat unit and a second comonomer repeat unit different from the first comonomer repeat unit; characterized in that the first comonomer repeat unit comprises a silacyclopentadithiophene moiety of formula: in which each of R 1, R 2, R 3, and R 4, independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C R, C OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl; the second comonomer repeat unit comprises a silacyclopentadithiophene moiety of formula, a benzothiadiazole moiety, a thiadiazoloquinoxaline moiety, a cyclopentadithiophene moiety, a cyclopentadithiophene oxide moiety, a benzoisothiazole moiety, a benzothiazole moiety, a thiophene oxide moiety, a thienothiophene moiety, a thienothiophene oxide moiety, a dithienothiophene moiety, a dithienothiophene oxide moiety, a tetrahydroisoindole moiety, a fluorenone moiety, a thiazole moiety, a selenophene moiety, a silole moiety, a thiazolothiazole moiety, a cyclopentadithiazole moiety, a naphthothiadiazole moiety, a thienopyrazine moiety, an oxazole moiety, an imidazole moiety, a pyrimidine moiety, a benzoxazole moiety, or a benzimidazole moiety; and the article is configured as a photovoltaic cell. a first electrode (120; 220; 240); a second electrode (160; 240; 260); and a photoactive material (140; 230; 350) disposed between the first (120; 220; 240) and second electrodes (160; 240; 260), the photoactive material (140; 230; 350) comprising a polymer including a first comonomer repeat unit and a second comonomer repeat unit different from the first comonomer repeat unit; characterized in that the first comonomer repeat unit comprises a silacyclopentadithiophene moiety of formula: in which each of R 1, R 2, R 3, and R 4, independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C R, C OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl; the second comonomer repeat unit comprises a silacyclopentadithiophene moiety of formula, a benzothiadiazole moiety, a thiadiazoloquinoxaline moiety, a cyclopentadithiophene moiety, a cyclopentadithiophene oxide moiety, a benzoisothiazole moiety, a benzothiazole moiety, a thiophene oxide moiety, a thienothiophene moiety, a thienothiophene oxide moiety, a dithienothiophene moiety, a dithienothiophene oxide moiety, a tetrahydroisoindole moiety, a fluorenone moiety, a thiazole moiety, a selenophene moiety, a silole moiety, a thiazolothiazole moiety, a cyclopentadithiazole moiety, a naphthothiadiazole moiety, a thienopyrazine moiety, an oxazole moiety, an imidazole moiety, a pyrimidine moiety, a benzoxazole moiety, or a benzimidazole moiety; and the article is configured as a photovoltaic cell.