Photovoltaic cell with thiazole-containing polymer

A polymer, comprising:

• a first comonomer repeat unit comprising a thiazolothiazole moiety;
• a second comonomer repeat unit comprising a thiophene moiety;
• and
• a third comonomer repeat unit comprising a silacyclopentadithiophene moiety, 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 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.