NOVELTY - A photoactive material comprises a donor substance and an acceptor substance. The donor substance comprises terminal heteroarylcyanovinylene group-containing compound (a) (I). The acceptor substance comprises terminal heteroarylcyanovinylene group-containing compound (b) (I) which is same or different from compound (a).    USE - Photoactive material is used for sensor and solar cell for photoelectric conversion device (all claimed). Uses include but are not limited to organic field effect transistor, light-emitting diodes, photovoltaic cells, photodetectors, memory cells, radio-frequency identification tag, liquid crystal display device and organic electroluminescent display device.    ADVANTAGE - The photoactive material has excellent luminous efficiency, high open circuit voltage and high crystallinity.    DETAILED DESCRIPTION - A photoactive material comprises a donor substance and an acceptor substance. The donor substance comprises terminal heteroarylcyanovinylene group-containing compound (a) of formula (I). The acceptor substance comprises terminal heteroarylcyanovinylene group-containing compound (b) (I) which is different from compound (a).    Q=linking unit;    r=0 or 1;    R1,R2=H, halo, CN or optionally substituted alkyl;    A,B'=group of formula (a) or (b);    W1-W6=N or C-R';    Z1,Z2=bivalent group chosen from O, S, Se, N-R, and groups of formulae (c)-(h);    W7-W10=W1;    Z3,Z4=bivalent group chosen from O, S, Se, N-R, and groups (c)-(f);    R=H, or alkyl, cycloalkyl, aryl or heteroaryl (all optionally substituted);    R'=H, halo, alkoxy, aryloxy, NO2, CN, COR", COOR", SO2R", SO3R", or alkyl or aryl (both optionally substituted);and    R"=aryl, 1-10C alkyl or 5-7C cycloalkyl (all optionally substituted), in which one oxygen atom or two nonadjacent oxygen atoms is optionally inserted between respective C atoms of alkyl or cycloalkyl.    (i) An uninterrupted pi -electron system extends from A to B'; (ii) When W1-W3 is C-R' and Z1 is group (c); (iii) When W4-W6 is C-R' and Z2 is group (c); and (iv) Carbon atoms of the two adjacent C-R' link together to form an aromatic ring, heteroaromatic ring or aliphatic ring. INDEPENDENT CLAIMS are included for the following:    (1) usage of terminal heteroarylcyanovinylene group-containing compound (I) as donor substance or acceptor substance in a photoactive material;    (2) cyano group-containing compound of formula (III); and    (3) usage of cyano group-containing compound (III) in synthesis of terminal heteroarylcyanovinylene group-containing compound (I).