TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Composition: The photovoltaic module further has transparent front substrate (14), front encapsulant (13) and photovoltaic cell (15).    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The ultraviolet reflectivity of the layer (L1) is more than the ultraviolet reflectivity of the layer (L2). The inorganic particles (A) are chosen from barium sulfate, aluminum nitride, boron nitride, boron arsenide, gallium nitride, zinc sulfide, zinc oxide and tin oxide. The inorganic particles (B) are chosen from titanium dioxide, aluminum arsenide, gallium arsenide, gallium sulfide, tin sulfide, lead sulfide, silicon carbide and barium titanate. The multi-layer film further has transparent layer (L3) including inorganic particles (A) having band gap energy of 3.3 eV or more provided between layer (L1) and layer (L2), and substrate provided in the lower portion of the layer (L2). Preferred Properties: The multi-layer film has ultraviolet reflectance of 10% or more at wavelength of 280-400 nm, and visible light reflectance of 60% or more at wavelength of 400-1200 nm. The thickness of the layer (L1) is 1-1000 microns, and layer (L2) is 1-1000 microns.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The layer (L1) and layer (L2) further contain matrix resin, and antioxidant, light stabilizer, heat stabilizer or ultraviolet stabilizer. The content of matrix resin is 10-200 pts. wt. with respect to 100 pts. wt. inorganic particles. The matrix resin is thermoplastic resin and/or thermosetting resin, preferably polyolefin resin, acrylic resin, fluorine-based resin, polyester resin, polycarbonate resin, polyamide resin, polyarylate resin, polyethersulfone resin, polysulfone resin, polyacrylonitrile, aromatic vinyl resin, silane-modified olefin resin, polyurethane resin, epoxy resin and/or ethylene vinyl acetate resin. The substrate is aluminum, iron, polyethylene terephthalate, polyethylene naphthalate or polybutylene terephthalate single sheet, laminated sheet or co-extruded material. Preferred Process: At least one surface of the substrate is subjected to plasma treatment, corona treatment, primer process, anchor agent treatment, coupling agent treatment or thermal process. Preferred Property: The thickness of the substrate is 50-500 microns.