TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The photovoltaic device or solar cell comprises at least one device comprising a cadmium sulfide/cadmium telluride solar cell, a copper indium gallium diselenide solar cell, an amorphous silicon solar cell, a microcrystalline silicon solar cell or a crystalline silicon solar cell. The photovoltaic module further comprises a refractive index matching liquid or optical adhesive that is used to attach the wavelength conversion luminescent medium to a light incident surface of the photovoltaic device or solar cell.    TECHNOLOGY FOCUS - POLYMERS - Preparation: No preparation method is given. Preferred Components: The polymer matrix comprises a substance of polyethylene terephthalate, polymethyl methacrylate, polyvinyl butyral, ethylene vinyl acetate, ethylene tetrafluoroethylene, polyimide, amorphous polycarbonate, polystyrene, siloxane sol-gel, polyurethane and/or polyacrylate. The refractive index of the polymer matrix material is 1.4-1.7. The luminescent dye is present in the polymer matrix in an amount of 0.01-3 wt.%. The wavelength conversion luminescent medium is a film having a thickness of 0.1 mu m to 1 mm. Preferred Definitions:    D1, D2 = phenyl or aryl; and    L1 = 1,2-ethylene, acetylene, 1,4-phenylene, 1,1-biphenyl-4,4'-diyl, naphthalene-2,6-diyl, naphthalene-1,4-diyl, 9H-fluorene-2,7-diyl, perylene-3,9-diyl, perylene-3,10-diyl or pyrene-1,6-diyl, 1H-pyrrole-2,5-diyl, furan-2,5-diyl, thiophen-2,5-diyl, thieno(3,2-b)thiophene-2,5-diyl, benzo(c)thiophene-1,3-diyl, dibenzo(b,d)thiophene-2,8-diyl, 9H-carbozole-3,6-diyl, 9H-carbozole-2,7-diyl, dibenzo(b,d)furan-2,8-diyl,10H-phenothiazine-3,7-diyl or 10H-phenothiazine-2,8-diyl (all optionally substituted).    SPECIFIC COMPOUNDS - 59 Compounds (A) are disclosed e.g. 4,7-bis(4-(N,N-diphenylamino)phenyl)-2-(pyridin-4-yl)-2H-benzo(d)(1,2,3)triazole of formula (Ia), 4,7-bis(4-phenoxyphenyl)-2-(pyridin-4-yl)-2H-benzo(d)(1,2,3)triazole, 4,7-di(benzofuran-2-yl)-2-(pyridin-4-yl)-2H-benzo(d)(1,2,3)triazole, 4,7-di(pyren-1-yl)-2-(pyridin-4-yl)-2H-benzo(d)(1,2,3)triazole and 4-(4-methoxyphenyl)-7-(pyren-1-yl)-2-(pyridin-4-yl)-2H-benzo(d)(1,2,3)triazole.    EXAMPLE - 4,7-Dibromo-2-(pyridin-4-yl)-2H-benzo(d)(1,2,3)triazole (1.95 g), sodium carbonate (2.69 g), 4-(diphenylamino)phenylboronic acid (3.47 g), tetrakis(triphenylphosphine)palladium (0) (0.58 g), water (20 ml), dioxane (80 ml), and toluene (10 ml) were heated under argon at 110 degrees C for 48 hours. The reaction mixture was poured into water (200 ml), diluted with dichloromethane (200 ml), treated with 2 N sodium hydroxide (50 ml), stirred for 1 hour, and the dichloromethane layer was separated. The aqueous phase was washed with dichloromethane (200 ml). Both dichloromethane solutions were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to give 4,7-bis(4-(N,N-diphenylamino)phenyl)-2-(pyridin-4-yl)-2H-benzo(d)(1,2,3)triazole (50%).