TECHNOLOGY FOCUS - ELECTRONICS - Preferred Process: The wavelength conversion film is applied to the solar energy conversion device using a roll laminator. The solar energy conversion device comprises an amorphous silicon solar cell, a microcrystalline silicon solar cell, or a crystalline silicon solar cell.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The photostable chromophore is an organic dye consisting of perylene derivative dye, benzotriazole derivative dye or benzothiadiazole derivative dye. The photostable chromophore is a substituted 2H-benzotriazole compound of formula (I)-(VI), substituted fused benzene compound of formula (VII), or perylene compound of formula (VIII) or (IX). The wavelength conversion layer comprises at least two different photostable chromophores, where at least one photostable chromophore is an up-conversion chromophore and at least one photostable chromophore is a downshifting chromophore; and a first wavelength conversion sublayer and a second wavelength conversion sublayer. The amount of the photostable chromophore is 0.01-3 wt.%. The thickness of the wavelength conversion layer is 50 mu m to 1 mm and the wavelength conversion film is 10 mu m to 2 mm.A10, A11 = alkyl, alkenyl, heteroalkyl, aryl, heteroaryl, amino, amido, cyclic amido, cyclic imido, alkoxy, carboxy or carbonyl (all optionally substituted);i = 0-100;A2 = alkylene, alkenylene, arylene, heteroarylene (all optionally substituted), ketone, ester or -Ar1-N(R1)-C(=O)-R2-C(=O)-N(R1)-Ar1-;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; orR1R2 = a ring;D1, D2 = alkoxy, aryloxy, acyloxy, alkyl, aryl, heteroaryl, amino (all optionally substituted), H, amido, cyclic amido or cyclic imido, provided that D1 and D2 are not both H; andL11 = alkylene, alkenylene, alkynylene, arylene or heteroarylene (all optionally substituted);R4a = -N(R1a)-C(=O)(R3a) or optionally substituted cyclic imido; eitherR1a = H, alkyl, alkenyl, aryl, heteroaryl, aralkyl or alkaryl; andR3a = alkyl, alkenyl, aryl or heteroaryl (all optionally substituted); orR1aR3a = a ring;R2a = alkylene, alkenylene, arylene or heteroarylene (all optionally substituted);R5a = alkoxy, aryloxy (both optionally substituted) or amino;Z, Z1 = O, S, Se, Te, NR6c, CR6c=CR6c or CR6c=N;R6c = H, optionally substitute 1-6C-alkyl, or optionally substituted 1-10C-aryl;j, k = 0-2;Y1, Y2 = aryl, alkyl, cycloalkyl, alkoxy or amino (all optionally substituted);R1d, R1e = H, 1-10C-alkyl, 3-10C-cycloalkyl, 1-10C-alkoxy, 6-18C-aryl or 6-20C-aralkyl;m, n = 1-5; andR1f, R1g = 6-18C-aryl or 6-10C-aralkyl.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The protection layer and polymer matrix comprise a material consisting of polyethylene terephthalate, polymethyl methacrylate, polyvinyl butyral, ethylene vinyl acetate, ethylene tetrafluoroethylene, polyimide, amorphous polycarbonate, polystyrene, siloxane sol-gel, polyurethane and/or polyacrylate. The adhesive layer comprises a substance consisting of acrylic, ethylene vinyl acetate and/or polyurethane. The protection layer is configured to inhibit penetration of oxygen and moisture into the wavelength conversion layer. The removable liner comprises a material, which is fluoropolymers or polyethylene terephthalate. The light incident surface of the solar energy conversion device is a material comprising a glass or a polymer. The thickness of the protection layer is 50 mu m to 1 mm, the adhesive layer is 1-100 mu m and the removable liner is 10-100 mu m.