TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The first poly(thiophene) is of formula (I) and second poly(thiophene) is of formula (II). The first poly(thiophene) is functionalized with an electron-donating and/or an electron-accepting moiety, selected to be capable of interacting electrochemically with the n-type material. The second poly(thiophene) is a homopolymer, preferably a poly(3-alkyl-thiophene), and is functionalized at least the 3- or 4-position with alkyl, heteroalkyl, cycloalkyl or heterocycloalkyl (all optionally substituted). The composition comprises the first poly(thiophene) and the second poly(thiophene) in a ratio of 0.05:0.95, 0.1:0.9, 0.15:0.85, 0.2:0.8, 0.25:0.75, 0.3:0.7, 0.4:0.6 or 0.5:0.5 or in a ratio of 0.01:0.99-0.5:0.5, 0.05:0.95-0.4:0.6, 0.05:0.95-0.25:0.75, 0.1:0.9-0.3:0.7 or 0.15:0.85-0.25:0.75 based on weight. In the composition the first poly(thiophene) has a degree of regioregularity of greater than 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 99.5%. The n-type materials are fullerenes, inorganic nanoparticles, oxadiazoles, discotic liquid crystals, carbon nanorods, inorganic nanorods and/or polymers containing moieties capable of accepting electrons or forming stable anions, preferably the fullerene that is optionally substituted. The n-material is phenyl-C61-butyric acid methyl ester. The ratio of total poly(thiophene) and the n-type material is 0.5:2-2:0.5, 0.5:1.5-1.5:0.5 or 0.75:1.25-1.25:0.75 based on weight. The ratio of total poly(thiophene) and n-type material is 1:5, 1:4, 1:3, 1:2, 1:1.5, 1:1.25, 1:1.15, 1:1, 1:1.05, 1.05:1, 1.1:1, 1.25:1, 1.5:1, 2:1, 3:1, 4:1 or 5:1. The photovoltaic cell further comprises at least two electrodes. In photovoltaic cell the composition: is positioned between the two electrodes; and is formed as a film. The film has a thickness of 1-nm to 1 mm, preferably 100 nm-300 nm.R1 = alkyl, aryl, heteroalkyl aryl, heteroaryl, arylalkyl, arylheteroalkyl or heteroarylalkyl (all optionally substituted) or H (preferred);R2 = R1, substituted phenyl compounds of formula (III), (-L-X-aryl), phenoxy moieties of formula (IV) or (V), substituted phenoxy compounds of formula (V)-(VIII), biphenyl oxy moiety of formula (IX), naphthoxy moiety of formula (X), 9-anthra oxy moiety of formula (XI), 4-tert-butylphenoxy moiety of formula (XII), substituted pentacyclo(6.6.6.0(2,7).0(9,14).0(15,20))icosa-2,4,6,9(14),10,12,15(20),16,18-nonaene moiety of formula (XIII), C(F3-(CF2)v-L)- or H;v = 4;X = hetero atom which is optionally present, preferably O, N or S;R7 = alkyl, aryl, heteroalkyl aryl or heteroaryl (all optionally substituted) or H;L = linking group, alkyl, hetero aryl or (CH2)w;R3, R5 = alkyl, heteroalkyl, cycloalkyl or heterocycloalkyl (all optionally substituted) or H (preferred);R6 = alkyl, heteroalkyl, cycloalkyl or heterocycloalkyl (all optionally substituted) or H;R4 = alkyl, heteroalkyl, cycloalkyl or heterocycloalkyl (all optionally substituted) or H, preferably hexyl;n, m = 2-100000000;p = 1 (preferred), 3 or 5; andw = 1-24, 2-24, 1-12, 2-12 or 4-10.Provided that at least one of R1 or R2 is not H. EXAMPLE - No suitable example given.