TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The solar energy conversion module further comprises: a light incident surface for the solar cell, where the light incident surface is present (a) between the microstructured wavelength conversion film and the solar cell, (b) over the microstructured wavelength conversion film and (c) between the microstructured wavelength conversion film and the luminescent medium layer; and a refractive index matching liquid that is used to attach the microstructured wavelength conversion film to the light incident surface, or used to attach the luminescent medium layer to the light incident surface. The solar cell is cadmium sulfide/cadmium telluride solar cell, copper indium gallium diselenide solar cell, amorphous silicon solar cell, microcrystalline silicon solar cell or crystalline silicon solar cell. Preferred Method: The method (M2) further comprises applying the microstructured wavelength conversion film onto the light incident surface.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The luminescent dye: is present in the first polymer matrix of the luminescent medium layer at 0.01-3 wt.%, preferably 0.05-1 wt.%; and comprises an organic dye, preferably perylene derivative dyes, benzotriazole derivative dyes or benzothiadiazole derivative dyes. The luminescent dye is a substituted 2H-benzotriazole of formula (Ia), (Ib) or (IIIa), a substituted 4,7-diphenyl-2H-benzotriazole of formula (IIIb), a substituted 2H-benzoimidazole of formula (IV), or a substituted perylene of formula (Va) or (Vb)i = 0-100;A3, A1 = aryl, heteroaryl (preferably -N(R1)-C(=O)-R3), alkyl, alkenyl, heteroalkyl, amino, amido, cyclic amido, cyclic imido, alkoxy, carboxy or carbonyl (all optionally substituted);A2 = -Ar1-N(R1)-(=O)-R2(=O)-N(R1)-Ar1- (preferred), alkylene, alkenylene, arylene, heteroarylene (all optionally substituted), ketone or ester;Ar1 = aryl or heteroaryl (both optionally substituted); eitherR1 = H, alkyl, alkenyl, aryl, heteroaryl, aralkyl or alkaryl; andR2 = alkylene, alkenylene, arylene, heteroarylene (all optionally substituted), ketone or ester; orR1+R2 = ring;D1, D2 = alkoxy, aryloxy, acyloxy, alkyl, aryl, heteroaryl, amino, amido, cyclic amido, cyclic imido (all optionally substituted) or H;L1 = alkylene, alkenylene, alkynylene, arylene or heteroarylene (all optionally substituted);R3 = alkyl, alkenyl, aryl or heteroaryl (all optionally substituted);R5 = alkoxy, aryloxy, acyloxy (all optionally substituted) or amino;Z1, Z2 = -O-, -S-, -Se-, -Te-, -NR6-, -CR6=CR6-, or -CR6=N-;R6 = 1-6C alkyl, 1-10C aryl (both optionally substituted) or H;j, k = 0-2;R11, R12 = H, 1-10C alkyl, 3-10C cycloalkyl, 1-10C alkoxy, 6-18C aryl or 6-20C aralkyl;m, n = 1-5; andR13, R14 = 6-18C aryl or 6-20C aralkyl.Provided that D1 and D2 are not both hydrogen.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The microstructured wavelength conversion film further comprises a microstructured polymer layer over the luminescent medium layer, where the microstructured polymer layer comprises a second optically transparent polymer matrix. The structures: are grooves, pyramids, prisms, cones, blocks, rings and/or pillars; and have a peak to valley distance of 0.01-100 mu m, preferably 1-50 mu m. The microstructured wavelength conversion film has a thickness of 0.1 mu m to 1 mm, preferably 0.5 mu m to 0.5 mm. The second optically transparent polymer matrix and first optically transparent polymer matrix comprise a substance comprising 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 first polymer matrix material is 1.4-1.7. EXAMPLE - Polyvinyl butyral (PVB) powder was dissolved in tetrachloroethylene at a predetermined ratio of 20 wt.% to form PVB polymer solution. The resultant PVB polymer solution was then mixed with diisobutyl 4,10-bis(4-(trifluoromethyl)phenyl)perylene-3,9-dicarboxylate at a weight ratio of 0.3 wt.% to obtain a dye-containing polymer solution. The resultant dye-containing polymer solution was then directly subjected to casting onto a glass substrate, and the substrate was heat treated from room from room temperature up to 100 degrees C in 2 hours. Then the remaining solvent was completely removed by further vacuum heating at 130 degrees C for overnight to obtain a dye/polymer thin film. Then the dye/polymer thin film was peeled off under the water and dried out the free-standing polymer film (before forming the microstructures) to obtain a luminescent medium layer. Then microstructures were formed on the top surface of the luminescent medium layer by embossing at elevated temperatures (in which a master film was used as a cast which was hot pressed against the film until the structures are formed on the surface, and a commercial prismatic master film with grooves was used as a master). Then pyramids were prepared by performing the embossing twice to obtain the microstructured wavelength conversion film.