TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The structure of the repeating base unit is of formula (A-B1)n (preferably 3,7-dithienyl-N-hexyldecyl-acridone-2,1,3-benzothiadiazole; thiophene-N-esyldecyl-acridone-thiophene-N-2-dodecyl-benzotriazole; 3,7-(3'-3''-hexyl)dithienyl-N-ethylhexyl-acridone-2,1,3-benzothiadiazole; 3,7-dithienyl-N-hexyldecyl-thioacridone-2,1,3-benzothiadiazole; or 3,7-(3'-3''-hexyl)dithienyl-N-hexyldecyl-acridone-2,1,3-benzothiadiazole). The repeating base unit (A-B1) is substituted on at least one (preferably at least two) of the positions of the molecular skeleton, with a group having a linear alkyl chain with at least 6C (preferably 12-24C).n=1-1000 (preferably 2-1000).    TECHNOLOGY FOCUS - POLYMERS - Preparation (Disclosed): Preparation of the copolymer involves: reacting aryl dibromide of formula Br-(A)-Br and an organo-stannic compound of formula R3Sn-(B1)-SnR3 in a presence of Pd-based catalyst to obtain copolymer of formula -(A-B1)-. Preferred Definitions:    X=S;    Y1=N-R';    R,R',R1a R'=buty, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, 2-ethylhexyl, 2-ethyloctyl, 2-ethyldecyl, 2-ethyldodecyl, 4-butylhexyl, 4-butyloctyl, 4-butyldecyl, 4-butyldodecyl, 2-hexyloctyl, 2-hexyldecyl, 4-hexyldecyl, isopropyl, 1-ethylpropyl, 1-butylpentyl, 1-hexylheptyl, 1-octylnonyl, 1-dodecyltridecyl, 1-hexadecylheptadecyl or 1-octadecylnona-decyl.    The benzene rings of the monomer unit (A) are substituted in positions 2 and 7 or 3 and 6 of formula (I).    EXAMPLE - Copolymer 3,7-dithienyl-N-hexyldecyl-acridone-2,1,3-benzothiadiazole was synthesized as follows: 3,7-(2',2''-dibromo)-dithienyl-N-hexyldecyl-acridone (764.8 mg), 4,7-bis pinacolboronic-2,1,3-benzothiadiazole ester (405.70 mg), anhydrous n-propanol (3 ml), aqueous solution 4 M of K2CO3 (1.5 ml) and deaerated toluene (100 ml) were charged, in an inert atmosphere, into a 250 ml two-necked flask equipped with a magnetic stirrer and reflux condenser. The reaction mixture was heated to 70 degrees C for 15 minutes and, at this temperature, Pd (0) tetrakis(triphenylphosphine) (122 mg) was added. The reaction mixture was left at this temperature for 40 hours. At the end of the period indicated, the mixture was concentrated to an eighth of the initial volume and then poured into 150 ml of methanol. After workup, copolymer (133.9 mg) with optical band-gap measured on a film of 1.71 eV, molecular weight (Mw) of 2350 Da and polydispersity index (PDI) of 1.549 was obtained.