TECHNOLOGY FOCUS - POLYMERS - Preferred Assembly: In the assembly, the barrier stack comprises a polymer layer and an inorganic barrier layer, where the inorganic barrier layer is an oxide layer. The multilayer film is transparent and flexible. The weatherable sheet and the substrate are fused. The barrier stack is between the weatherable sheet and the substrate at the point of fusion. The edge has been ultrasonically welded; or the edge has been laser fused. The electronic device comprises an edge seal material, a backsheet, or an encapsulant layer. Edge seal material comprises butyl rubber. The weatherable sheet is fused to the electronic device. The substrate comprises at least one of polyethylene terephthalate, polyethylene naphthalate, polyetheretherketone, polyaryletherketone, polyacrylate, polyetherimide, polyarylsulfone, polyethersulfone, polyamideimide, or polyimide. The weatherable sheet comprises a fluoropolymer, where the fluoropolymer comprises at least one of an ethylene tetrafluoro-ethylene copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, a tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, or a polyvinylidene fluoride. The assembly comprises a pressure sensitive adhesive layer between the weatherable sheet and the barrier stack. Pressure sensitive adhesive is an acrylate, a silicone, a polyisobutylene, a urea or its blend. It comprises at least one of UV stabilizer, a hindered amine light stabilizer, an antioxidant or a thermal stabilizer. The barrier stack oxide layer shares a siloxane bond with the barrier stack polymer layer. The electronic device is a photovoltaic cell, where the photovoltaic cell is copper indium gallium di-selenide (CIGS) cell. The substrate is heat stabilized. The barrier stack has a water vapor transmission rate of less than 0.005 cm3/m2/day at 50 degrees C and 100% relative humidity. It has an oxygen transmission rate of less than 0.005 cm3/m2/day at 23 degrees C and 90% relative humidity. The barrier stack comprises at least two oxide layers; or at least two polymers layers. The electronic device comprises a roof. The multilayer film has been fused around a perimeter of the assembly.