TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The structural units (A) are units whose main divalent structure is ethylene, phenylene, thiophene, pyrrole, fluorene, dithienocyclopentadiene, dithienothiophene, thienothiophene, isothianaphthalene, carbozole, thiazothiazole, optionally substituted with alkyl groups or alkyls functionalized with halogens, preferably fluoride or chloride, or ionic groups, preferably cationic, ammonium or quaternary phosphonium. The conjugated unit A contains phenothiazine divalent unit(s). The ratio between the sum of all the carbon atoms of the alkyl chains present in the repetitive base units of the copolymer and the number of aromatic rings present in the same units is 3.5-12. The structure of the copolymer envisages, in the main chain, conjugated units with six member rings bonded to vinylidene conjugated units or containing only five member rings. The copolymer has a structure which envisages, in the main chain, conjugated units with six member rings bonded to vinylidene conjugated units or containing only five member rings, where a part of the R or R' substituents, present on the monomer units, preferably greater than or equal to 30% comprises a hydrocarbyl group, preferably aliphatic, having 4-24C, substituted with a quaternary ammonium or phosphonium group. Preferred Structure: The structural units (A) are one or more of 21 benzene containing compounds, e.g. formula (i)-(v). The structure of the repetitive base unit is (A-B')n, (A-B'-A)n or (B-C'-A-C')n, or statistical (A-B')v-co-(A-C')z or ((A-B')-v-co-(C'-B')z), where C' is a further conjugated unit of type A. The copolymer of type (B'-C'-A-C')n comprises a conjugated structural unit of type -C'-A-C'. At least one of the radicals R and R' present on one of the monomer units of type (A) or (B'), bears an ionic group, preferably cationic group of the ammonium or quaternary phosphonium type, respectively of formula -R1-N(R2R3R4)+X- (II) and -R1-P(R2R3R4)+ X- (III). The copolymer comprises cationic group(s) including -(CH2)n-N(CH3)3+, -(CH2)n-N(CH2CH3)3+, -(CH2)n-N(CH3)(CH2CH2OCH2CH2)+, -(CH2)n-N(CH2-CH2OH)(CH2CH2OCH2CH2)+, -CH2CH2O-CH2CH2-N(CH3)3+, -(CH2CH2O)2-CH2CH2-N(CH3)3+, -(CH2CH2O)3-CH2CH2-N(CH3)3+, -(CH2)n-(NC5H5)+ (pyridine salt), -(CH2)n-N2C3H4+ (imidazole salt), or -(CH2)n-N(CH2CH2)CH+ (quinuclidine salt), where N belongs to the N-methylmorpholine ring.n=2-1000, preferably 5-1000;v, z=integers different from 0;(v+z)=2-1000, preferably 5-1000;C'=divalent conjugated group of vinylidene type, or heteroaromatic with 5 member rings, preferably thiophene or dithiophene, possibly substituted with R' groups;A=group comprising aromatic or heteroaromatic rings with 6 members, possibly condensed with each other or with 5 member rings, preferably phenothiazine, phenazine, carbazole, fluorine, or anthracene;R1=alkylene radical, possible branched, containing 2-12C, possibly also included in aromatic units;R2-R4=alkyl radicals containing 1-4C, possibly also containing OH groups; andX-=organic or inorganic monovalent anion including chloride, bromide, iodide, tetrafluoroborate, hexafluorophosphate, methylsulfate, trifluoromethanesulfonate, benzenesulfonate, toluenesulfonate, perchlorate, nitrate, preferably chloride or bromide anion.    TECHNOLOGY FOCUS - POLYMERS - Preferred Structure: The copolymer is one or more of 7 compounds, e.g. formulae (II)-(VI).n=5-1000;x, y=integers different from 0; or(x+y)=5-1000. EXAMPLE - 4,7-Dibromo-2-(2-hexyldecyl)-2H-benzotriazole (510.5 mg), 2,2'-bithiophene-5,5'-pinacolyl diboronate (439.5 mg), anhydrous ethanol (2 ml), 4M solution of potassium carbonate (1 ml), and deaerated toluene (85 ml) were introduced into a flask under an inert atmosphere. The reaction mixture was heated to 90 degrees C for 15 (no units given) and palladium (0) tetrakis(triphenylphosphine) were also subsequently added. The reaction mixture was then heated to 100 degrees C and maintained at this temperature for 35 hours. The reaction mixture was then concentrated to an eighth of its initial volume and poured into methanol (150 ml). The solid obtained was filtered, re-dissolved in chloroform (10 ml) and re-precipitated in methanol (150 ml). The polymer thus obtained was filtered and left to dry in an oven at 55 degrees C for 3 days. Black solid of copolymer (1) (354.1 mg) were obtained. The band gap measured for copolymer (1) was 1.92 eV.