NOVELTY - A derivatized anthra(2,3-b:6,7-b')dithiophene (ADT) based monomer is new.    USE - The derivatized ADT based monomer is useful for preparing monomer solution, polymer solution, bulk heterojunction material, and organic solar cell device (all claimed).    ADVANTAGE - The ADT-based conjugated polymers are for high efficiency organic solar cell applications. The thiophene derivatized ADT-based conjugated polymers compositions achieved power conversion efficiencies (PCE) in the range of about 0.92-1.0% in bulk heterojunction solar cells.    DETAILED DESCRIPTION - A derivatized anthra(2,3-b:6,7-b')dithiophene (ADT) based monomer of formula 1, is new.    Ar1=selected from benzene, furan, thiophene, selenophene, pyrole, pyran, pyridine, oxazole, thiazole, imidazole and its derivatives; and    Ar'=selected from thieno(3,4-b)thiophene, benzothiadiazole, thieno(3,4-c)pyrrole-4,6(5H)-dione and its derivatives.    INDEPENDENT CLAIMS are included for:    (1) a monomer solution, comprising: (a) benzene, furan, thiophene, selenophene, pyrole, pyran, pyridine, oxazole, thiazole or imidazole derivatized anthra(2,3-b:6,7-b')dithiophene monomer dissolved in anhydrous tetrahydrofuran, from about 3 to about 5 mmol; (b) N-butyllithium, from about 8.5 to about 9.5 mmol; and (c) trimethylstannane, from about 10 to about 12 mmol;    (2) a polymer solution comprising: (a) first reactant selected from 1-(4,6-dibromo-thieno(3,4-b)thiophen-2-yl)-2-ethylhexan-1-one and its derivative dissolved in from about 4:1 to about 6:1 toluene and dimethylformamide, from about 0.25 to about 0.35 mmol; (b) second reactant selected from (5,11-bis(5-(2-ethylhexyl)thiophen-2-yl)anthra(2,3-b:6,7-b')dithiophene-2,8-diyl)bis(trimethylstannane) and its derivatives dissolved in the toluene and dimethylformamide solvent, from about 0.25 to about 0.35 mmol; and (c) palladium-tetrakis(triphenylphosphine) catalyst, from about 1.5 to about 2.5 mg/ml;    (3) a bulk heterojunction material comprising: (a) derivatized anthra(2,3-b:6,7-b')dithiophene based polymer as a donor; and (b) an acceptor; and    (4) an organic solar cell device comprising: (a) an aluminum or silver layer; (b) a bulk heterojunction layer, where the bulk heterojunction layer comprises: (i) derivatized anthra(2,3-b:6,7-b')dithiophene based polymer as a donor; and (ii) an acceptor; and (c) an indium tin oxide glass layer.