NOVELTY - A solar cell module comprises solar cell assembly and a reflecting back encapsulant laminated to the back non-sun-facing side of the solar cell assembly, where the solar cell assembly comprises at least one electrically interconnected solar cell and has a front sun-facing side and back non-sun-facing side; and the reflecting back encapsulant comprises a co-extrusion or extrusion coated multilayer sheet, where the multilayer sheet comprises a reflecting layer and a first tie layer co-extruded or extrusion coated on first side of reflecting layer, and optionally a second tie layer.    USE - As solar cell module (claimed).    ADVANTAGE - The reflecting back encapsulant has a reflectance of greater than or equal to 80% at a wavelength of 420-1150 nm. The improved reflectance results in improved cell efficiency, compared to prior art back encapsulants. The reflecting back encapsulant also maintains good adhesion to the solar cell assembly and the back sheet. Because the solar cell assemblies have uneven surfaces with peaks and voids, during the lamination process, the reflecting back encapsulant material melts or softens to some degree, and flows around the peaks and fills the voids of the solar cell assembly.    DETAILED DESCRIPTION - A solar cell module comprises a solar cell assembly and a reflecting back encapsulant, where the solar cell assembly comprises at least one electrically interconnected solar cell and has a front sun-facing side and a back non-sun-facing side and the reflecting back encapsulant comprises a co-extrusion or extrusion coated multilayer sheet, where i) the multilayer sheet comprises a reflecting layer, a first tie layer that is co-extruded or extrusion coated on a first side of the reflecting layer, and optionally a second tie layer that is co-extruded or extrusion coated on a second side of the reflecting layer; ii) the multilayer sheet has a total thickness of 2-50 mil (51-1270 mu m); iii) the first tie layer comprises a first polymeric material and the second tie layer comprises a second polymeric material, first and the second polymeric materials have a melting temperature of 80-165 degrees C and an adhesion to glass of at least 30 lb/inch when measured with the T-peel test; iv) the first tie layer has a thickness of 1-8 mil (25-203 mu m); v) the optional second tie layer has a thickness of 1-35 mil (25-889 mu m); vi) the reflecting layer comprises a third polymeric material having a melting temperature of 80-165 degrees C and further comprises filler (greater than 25-90 wt.%, based on the total weight of the reflecting layer composition) having a refractive index of above 1.4 and a mean particle size of 0.1-20 mu m; vii) the reflecting layer has a thickness of 1-35 mil (25-889 mu m); and viii) the reflecting back encapsulant is laminated to the back non-sun-facing side of the solar cell assembly with the first tie layer positioned adjacent to the solar cell assembly. The solar cell module further comprises a back sheet laminated to the reflecting back encapsulant; a front encapsulant laminated to the front sun-facing side of the solar cell assembly; and a front sheet laminated to the front encapsulant. The solar cell is wafer-based solar cell selected from crystalline silicon and multi-crystalline silicone based solar cell; or is thin film solar cell selected from amorphous silicon, microcrystalline silicon, cadmium telluride, copper indium selenide, copper indium/gallium diselenide, light absorbing dye, and organic semiconductors based solar cell.