NOVELTY - Article comprises: a first electrode; a second electrode; and a photoactive material disposed between the first and second electrodes, in which the photoactive material comprises a polymer including a first comonomer repeat unit and a second comonomer repeat unit different from the first comonomer repeat unit.    USE - Used as article such as photovoltaic cell (claimed). The polymer is useful in systems and organic semiconductive devices, such as field effect transistors, photodetectors (e.g. infrared detectors), photovoltaic detectors, imaging devices (e.g. red, green, and blue imaging device for cameras or medical imaging systems), light emitting diodes (LEDs) (e.g. organic LEDs or infrared or near IR LEDs), lasing devices, conversion layers (e.g. layers that convert visible emission into infrared emission), amplifiers and emitters for telecommunication (e.g. dopants for fibers), storage elements (e.g. holographic storage elements), and electrochromic devices (e.g. electrochromic displays).    ADVANTAGE - The polymer has improved solubility in organic solvents, and provides photoactive layer with improved morphology and an electron donor material with improved semiconductive properties. The polymer is capable of absorbing the light at long wavelength.    DETAILED DESCRIPTION - Article comprises: a first electrode; a second electrode; and a photoactive material disposed between the first and second electrodes, in which the photoactive material comprises a polymer including a first comonomer repeat unit and a second comonomer repeat unit different from the first comonomer repeat unit, where: the first comonomer repeat unit comprises a silacyclopentadithiophene moiety of formula (I); and the second comonomer repeat unit comprises a thiophene moiety substituted with 1-20C alkyl, 1-20C alkoxy, 3-20C cycloalkyl, 1-20C heterocycloalkyl, aryl, heteroaryl, halo, CN, OR1a, C(O)R1a, C(O)OR or SO2R1a, or fused with a 1,4-dioxane moiety.    R1-R4 = H, 1-20C alkyl, 1-20C alkoxy, 3-20C cycloalkyl, 1-20C heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR or SO2R; and    R, R1a = H, 1-20C alkyl, 1-20C alkoxy, aryl, heteroaryl, 3-20C cycloalkyl or 1-20C heterocycloalkyl.    An INDEPENDENT CLAIM is included for a polymer comprising a first comonomer repeat unit comprising (I).    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a photovoltaic cell.    Photovoltaic cell (100)    Substrate (110)    Cathode (120)    Carrier layer (130)    Active layer. (140)