TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The n-type organic semiconductor compound is selected from graphene and optionally substituted fullerenes (preferably (6,6)-phenyl- butyric acid methyl ester derivatized methano 60C fullerene (PCBM-60C), PCBM-70C, PCBM-61C, PCBM-71C, bis-PCBM-61C, bis-PCBM-71C, an indene-C60-fullerene bisaduct (ICBA) and graphene).    TECHNOLOGY FOCUS - POLYMERS - Preparation (claimed): Preparation of the polymer (D1) involves: coupling at least one monomer (VI) with each other, and/or with at least one monomer selected from R7-(Ar1)a-A1-(Ar2)c-R8, R7-(Ar1)-R8, and R7-(Ar3)-R8, in an aryl-aryl coupling reaction to give the polymer (D1). Preferred Compound: The polymer (D1) comprises at least one unit of formula -((Ar1)a-(U')b-(Ar2)c-(Ar3)d)- (II), and further comprises at least one repeating unit of formula -((Ar1)a-(A1)b-(Ar2)c-(Ar3)d)- (III). The compound (D1) is selected from 12 compounds as given in the specification, for e.g. compound of formula (I').U'=unit of compound (I);Ar1, Ar2, and Ar3=aryl or heteroaryl, preferably has 5-30 ring atoms (optionally substituted with at least R1a);R1a=1-40C silyl, 1-40C carbyl or 1-40C hydrocarbyl (all optionally substituted with at least one hetero atom), F, Br, Cl, -CN, -NC, -NCO, -NCS, -OCN, -SCN, -C(O)NR'aR'b, -C(O)X'a, -C(O)R'a, -NH2, -NR'aR'b, -SH, -SR'a, -SO3H, -SO2R'a, -OH, -NO2, -CF3, -SF5, or P'-Sp'-;R'a and R'b=H or optionally substituted 1-40C carbyl or hydrocarbyl;P'=polymerizable or crosslinkable group;Sp'=spacer group or single bond;X'a=F, Cl or Br;a, b, and c=0-2;d=0-10;A1=aryl or heteroaryl having 5-30 ring atoms and having electron donor properties (both optionally substituted with R1).Preferred Components: The mixture or polymer blend comprises the polymer (D1) and at least one n-type organic semiconductor compound. Preferred Definitions:    R1 and R2=straight-chain or branched 1-20C alkyl (optionally substituted with at least one F);    R3 and R4=alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkylcarbonyloxy (all of which are straight-chain or branched, are optionally fluorinated, and have 1-30C atoms), or aryl, aryloxy, heteroaryl or heteroaryloxy (all of which are optionally alkylated or alkoxylated and have 4-30 ring atoms).    EXAMPLE - No suitable example given.