TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The device comprises at least one cathode interlayer and at least one anode interlayer.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: In (A11): the electron acceptor unit is substituted thieno(3,4-c)pyrrole-4,6-dione moiety of formula (a1), substituted dithieno(3,2-c;2',3'-e)azepine-4,6-dione moiety (a2), substituted thieno(3,4-f)isoindole-5,7-dione moiety of formula (a3) or substituted isoindole-1,3-dione moiety of formula (a4); the second unit is terthiophene moiety of formula (a5); the second unit is an electron donor unit (D) and with the electron acceptor unit (A) comprise an alternating repeat unit of formula (-(D-A)-); the polymer has repeat unit of formula substituted dithieno(3,2-c;2',3'-e)azepine-4,6-dione terthiophene moiety of formula (a6) or substituted thieno(3,4-c)pyrrole-4,6-dione terthiophene moiety of formula (a7); the polymer has a molecular weight of 3000-300000; the photoactive component comprises a blend material comprising electron acceptor compound and the semiconducting compound functioning as an electron donor compound and the electron acceptor compound is (6,6)-phenyl-C61-butyric acid methyl ester or (6,6)-phenyl-C71-butyric acid methyl ester. In (A12): the electron donor unit comprises 3-10 optionally substituted thienyl moieties, where the electron donor unit is substituted thiophenyl moiety of formula (a8); the electron donor unit comprises terthiophene, where the electron donor unit is terthiophenyl or substituted terthiophene moiety of formula (a9)-(a13), or quaterthiophene, where the electron donor unit is quaterthiophenyl or substituted quaterthiophenyl moiety of formula (a14)-(a20); the polymer has molecular weight of 3000-300000 g/mol; and the photoactive component comprises a blend material comprising the electron donor compound and electron acceptor compound, which is (6,6)-phenyl-C61-butyric acid methyl ester or (6,6)-phenyl-C71-butyric acid methyl ester.R2, R3 = H or R4, preferably each of R2 and R3 is H or at least one of R2 and/or at least one of R3 is R4;R4 = -L-1-40C (preferably 6-40C) alkyl, -L-2-40C (preferably 6-40C) alkenyl (both optionally substituted with 1-10 of halo, -CN, -NH2, -NH(1-20C alkyl), -N(1-20C alkyl)2, -SiH3, -Si(H(1-20C alkyl)2, -SiH2(1-20C alkyl), -Si(1-20C alkyl)3, -O-1-20C alkyl or -S-1-20C alkyl), halo or -L-1-40C (preferably 6-40C) haloalkyl;L = O, S or covalent bond; andm = 3-8, preferably 3-5. Preferred Definitions:    R1 = branched 3-40C alkyl, branched 4-40C alkenyl or branched 3-40C haloalkyl.