TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Device: The photovoltaic cell comprises a crosslinked polymer network formed from a mixture of reactive mesogens (I). The cell is provided with a reflective coating on the rear side. It contains light-absorbing, electron-donating, and electron-accepting components. At least one of the components is a polymer network. The electron-donating and/or electron-accepting polymer network is formed by polymerization of individual reactive mesogen or mixture of reactive mesogens. The cell contains a polymer network formed by sequential formation of a gel, followed by removal of non-polymerizable component and its replacement by another component. The replacement component is polymerized to form a second polymer network. The cell contains a polymer network formed by sequential formation of partially crosslinked polymer network, followed by removal of non-polymerized monomers and its replacement by another component. The replacement component is polymerized to form a second polymer network. The polymer networks are manufactured as sheets or tiles that may be contact bonded to a substrate. The polymer networks are applied to non-planar surfaces, such as curved surfaces, by simple coating techniques.    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The photopolymerization utilizes UV radiation. It involves linear or cyclopolymerization. Photopolymerization involves radicalization of an end group (B) to form an initial radical of B-S-A-S-B' (II). The (B') radicalized end group of a first monomer reacts with an unradicalized end group (B) of a second monomer to form a cyclic entity. The reaction of B' radicalized end group of first monomer with the unradicalized end group (B) of second monomer is sterically controlled. Photopolymerization is conducted at room temperature.Preferred Components: The chromophore (A) is fluorene, vinylenephenylene, anthracene, perylene, benzothiadiazole, oxadiazole, thiophene, or derivative these materials. The chromophore is a compound of formula (A1)-(A5). The spacer (S) is an organic chain, e.g. aliphatic, amine, ester, or ether linkage; or derivate of these linkage. The spacer may be linear alkyl, branched alkyl, or alkenyl chains optionally including a heteroatom. The end group (B) is diene, e.g. 1,4-diene, 1,5-diene, 1,6-diene, or diene of formula (D1)-(D4). The diene functionalities are separated by an aliphatic linkage or an inert linkage, e.g. ether or amine linkage. The end group (B) may be a group of formula (B1)-(B3).Preferred Compounds: The reactive mesogen is of formula (Ia).R=a group of formula R1-R5.The reactive mesogen is a compound of formulae (1)-(4). The reactive mesogen may be a 1:1 mixture of compounds (1) and (2) (2 wt.% mixture), a 1:1 mixture of compounds (3) and (2) (2 wt.% mixture), a 1:1 mixture of compounds (4) and (1) (1 wt.% mixture), or reactive mesogen (1).