TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Disclosed): Preparation of the compound (A) involves converting perylenedicarboxylic acid diester compound of formula (II) into either dibromo or diiodo derivative of formula (III) by using a bromination/iodination reagent such as N-bromosuccinimide and N-iodosuccinimide, and coupling the dibromo or diiodo derivative (III) with trifluoromethyl group containing boronic acid derivative in the presence of a catalyst.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The polymer matrix comprises polymethyl methacrylate, polyvinyl butyral, ethylene vinyl acetate, ethylene tetrafluoroethylene, polyimide, amorphous polycarbonate, polystyrene, siloxane sol-gel, polyurethane and/or polyacrylate. Preferred Composition: The content of the luminescent dye present in the polymer matrix is 0.01-3 wt.%, preferably 0.05-1 wt.%. Preferred Properties: The polymer matrix has a refractive index of 1.4-1.7, preferably 1.450-1.550. The medium is in the form a film having a thickness of 0.1 mu m-1 mm, preferably 0.5 mu m-0.5 mm. The photovoltaic device(s) or solar cell comprises cadmium sulfide/cadmium telluride solar cell, or copper indium gallium diselenide solar cell. The photovoltaic module further contains a refractive index matching liquid or optical adhesive that is used to attach the organic down-shifting luminescent medium to the light incident surface substrate of the photovoltaic device(s) or solar cell. Preferred Definitions:    R1,R11=isopropyl, isobutyl, isohexyl, isooctyl, 2-ethyl-hexyl, diphenylmethyl, trityl or diphenyl;and    R2,R22=diphenylmethyl, trityl or diphenyl.    SPECIFIC COMPOUNDS - 2 Compounds (I) are specifically claimed i.e. diisobutyl 4,10-bis(4-(trifluoromethyl)phenyl)perylene-3,9-dicarboxylate of formula (Ia) and bis-(diphenylethyl) 4,10-dicyanoperylene-3,9-dicarboxylate.    EXAMPLE - N-Bromosuccinimide (7.85 g) was added to a solution of perylenedicarboxylic acid diisobutyl ester that was synthesized from the corresponding diacid derivative by esterification with isobutyl alcohol in dimethylformamide (50 ml) and heated to 65 degrees C for 3 hours until the initial suspension changes to a clear solution. Methanol (500 ml) was added to the stirred reaction mixture after the solution was cooled. The obtained heavy precipitate was separated by filtration and washed with small portion of cold methanol, and dried in a vacuum oven to give diisobutyl 4,10-dibromoperylene-3,9-dicarboxylate (9.6 g, 78%) (a). Tetrakis(triphenylphosphine)palladium(0) (500 mg) was added to a solution of the compound (a) (3.05 g), 4-trifluoromethylphenylboronic acid (2.09 g) in a mixture of toluene (50 ml), an aqueous solution of 2M sodium carbonate (20 ml) and ethanol (30 ml) under argon atmosphere. The reaction mixture was heated at 90 degrees C for 1 hour until clear separation of organic layer, water, and solid was observed. The organic layer was separated and filtered through Celite to remove the palladium catalyst, then the solvent was partially removed under vacuum. The product was precipitated from methanol, filtrated off, washed with cold methanol, and dried in a vacuum oven to give pure diisobutyl 4,10-bis(4-(trifluoromethyl)phenyl)perylene-3,9-dicarboxylate (3.30 g, 89%).