NOVELTY - Random conjugated copolymer (I) comprising one or more different donor (D) repeating units and at least one acceptor (A) repeating unit, is claimed, where: at least one of the D units has a solubilizing substituent; statistically a portion of the A repeating units are separated from each other by only one of the D units; and the A unit are adjacent to the D units having the solubilizing substituents.    USE - USE -. (I) is useful as a component of: electrochromic windows, mirrors, or displays; polymer photovoltaics to harvest solar energy and generate electricity; other photovoltaic devices; electronic paper; antistat conductors and transparent conductors; field effect transistors, super capacitors, batteries, and other electronic components; and near IR detectors. (I) is useful for reflective and transmissive electrochromic devices. (I) is useful as active layers in bulk heterojunction solar cells, active light absorbing layer in dye sensitized solar cells, and charge transport layer in field-effect transistor devices.    ADVANTAGE - (I) is black or colored in the neutral state and are highly transmissive in the oxidized state. (I) displays high optical contrasts in the visible region, and possesses improved switching speeds and switching stability. (I) exhibits improved: solubility, which allows lower fabrication costs and good scalability; and physical properties that allow improved electro-optic and mechanical properties compared to traditional colored-to-transmissive electrochromic polymer counterparts.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for preparing (I) comprising: providing at least two monomer comprising a D unit, where at least one of the monomers includes a substituted D unit comprising a 3,4-alkylenedioxythiophene substituted on the alkylene bridge, a 3,4-dialkoxythiophene, a 3,6-dialkoxytheino(3,2-b)thiophene, 3,5-dialkoxy-dithieno(3,2-b:2',3'-d)thiophene or an alkyl substituted thiophene, one or more first D unit comprising monomer have a pair of first reactive groups and at least one of the first D unit comprising monomers is a substituted D unit, and one or more second D units comprising monomers have a pair of second reactive groups that are complementary to the first reactive group; providing at least one monomer comprising an A unit comprising benzo(c)(1,2,5)thiadiazole, benzo(c)(1,2,5)oxadiazole, quinoxaline, benzo(d)(1,2,3)triazole, pyrido(3,4-b)pyrazine, cyanovinylene, thiazolo(5,4-d)thiazole, 1,3,4-thiadiazole, pyrrolo(3,4-c)pyrrole-1,4-dione, 2,2'-bithiazole, (1,2,5)thiadiazolo(3,4-c)pyridine, thieno(3,4-b)pyrazine, (1,2,5)oxadiazolo(3,4-c)pyridine, dicyanovinylene, (1,2,5)thiadiazolo(3,4-g)quinoxaline, 4-dicyanomethylenecyclopentadithiolene, benzo(c)thiophene or their derivatives, where the A unit has a pair of the second reactive groups; and polymerizing the D units with the A units, where the resulting random conjugated copolymer has the structures of formula -((D)x-A)n- or -((DA)x-(D1aA)y)n-.    x, y = greater than 1,where n(x+1) and 2n(x+y) are greater than or equal to 10;    D = first D units; and    D1a = other D units.