TECHNOLOGY FOCUS - CERAMICS AND GLASS - Preferred Components: The glass of the glass layer is a borosilicate glass or a soda lime glass. The total thickness of the glass element is less than 5 mm. The glass layer has a thickness of 0.1-2 mm, 0.1-4 mm, and/or the other glass layer has a thickness of 0.1-2 mm. The glass layer has a surface not facing the polymer layer which is covered with an anti-reflective coating. The glass layer has an embossed surface not facing the polymer layer. The back sheet is a glass layer. The glass layer facing the incoming radiation has a thickness of 1.5-4 mm and where the glass layer used as back sheet has a thickness of 1.5-4 mm and where the total thickness of the solar panel is less than 9 mm. The glass layer facing the incoming radiation is provided with an anti-reflective coating.    TECHNOLOGY FOCUS - POLYMERS - Preferred Sheet: The polymer sheet comprises at least two coextruded polymer layers and where the different luminescence downshifting compounds present in a first layer will absorb radiation at a lower wavelength than the different luminescence downshifting compounds present in a next layer. The sheet comprises two outer polymer layers and at least one inner polymer layer and where an outer polymer layer or both outer polymer layers has a melting point T1 of at least 10 degrees C below the melting point T2 of at least one inner polymer layer. Preferred Process: The process (P1) further involves preparing at least one master batch from polymer material and additives, and shaping the master batch material to particulates for use in the co-extrusion. The polymer sheet is obtained by co-extrusion of different polymer materials, which polymer materials are extruded at an extrusion temperature for each sub-layer so chosen that the largest difference in melt flow index of the polymers of the sub-layers at the extrusion temperature as applied for each sub-layer is lower than 3 MFI points. In the process (P2), the polymer sheet is comprised of at least three multiple coextruded thermoplastic polymer sub-layers comprising two outer sub-layers and at least one inner sub-layer and where at the lamination temperature the MFI of the inner sub-layer differs in a range of 0.5-10 points from the MFI of one or both of the outer sub-layers of the same layer. The polymer sheet is obtained by co-extrusion of different polymer materials which polymer materials are extruded at an extrusion temperature for each sub-layer so chosen that the largest difference in melt flow index of the polymers of the sub-layers at the extrusion temperature as applied for each sub-layer is lower than 5 MFI points, where the lamination temperature TL is higher than the extrusion temperature TC of an inner sub-layer; and where the temperature TC is higher than the extrusion temperature TA of an outer sub-layer and/or TB of the other outer sub-layer. The lamination temperature is 115-175 degrees C and the environment of the stack has a pressure of less than 30 mBar. Preferred Components: The two layers of the polymer sheet comprise a luminescence downshifting compound. The luminescence downshifting compound is present in a first polymer layer, which luminescence downshifting compound can absorb more radiation at a lower wavelength than the luminescence downshifting compound present in a next layer. The first polymer layer comprises a luminescence downshifting compound for at least partially absorbing UV radiation and re-emitting radiation at a higher wavelength. The two different luminescence downshifting compounds are selected to form a cascade and where the cascade is defined in that a compound in the cascade reemits radiation in a wavelength range at which a next compound absorbs radiation, and at least one luminescence downshifting compound for at least partially absorbing radiation having a certain wavelength and re-emitting radiation at a longer wavelength than the wavelength of the absorbed radiation. The first polymer layer comprises a luminescence downshifting compound for absorbing radiation at 280-400 nm and re-emitting radiation at 400-550 nm, another polymer layer comprises a luminescence downshifting compound for absorbing radiation at 360-470 nm and re-emitting radiation at 410-670 nm, and another polymer layer comprises a luminescence downshifting compound for absorbing radiation at 360-570 nm and re-emitting radiation at 410-750 nm. The polymer layer comprises ethylene vinyl acetate (EVA), ethylene vinyl alcohol (EVOH), polyvinylbutyral (PVB), polymethylmethacrylate (PMMA), alkylmethacrylate, alkylacrylate copolymers, polyurethanes, functionalized polyolefines, ionomers, and/or thermoplastic polydimethylsiloxane copolymers. The polymer composition of the layer comprising the luminescence downshifting compound is selected such that the light absorbing and emitting activity of the luminescence downshifting compound is not affected under accelerated weathering conditions according to ISO 4892 part 2, Method A, Cycle 2 for at least 100 hours. The polymer layer has high moisture and/or gas barrier properties. The polymer layers comprises an ethylene vinyl acetate polymer, preferably ethylene vinyl acetate has an acetate content of 12-45 wt.%. The luminescence downshifting compounds are present in multiple coextruded layers of an ethylene vinyl acetate polymer having an acetate content of 12-45 wt.%. The outer polymer layer comprises a silane coupling agent. The melting point T1 is 10-100 degrees C lower than the melting point T2. The inner polymer layer comprises an optionally hydrogenated polystyrene block copolymer with butadiene, isoprene and/or butylenes/ethylene copolymers (SIS, SBS and/or SEBS); a ethylene vinyl alcohol (EVOH) copolymer, a polymethacrylate polyacrylate block copolymer, a polyolefin, a polyolefine copolymer or terpolymer, or an olefin copolymer or terpolymer, with copolymerizable functionalized monomers such as methacyrylic acid (ionomer). The outer layer comprises an ethylene vinyl acetate co-polymer, preferably ethylene vinyl acetate has an acetate content of more than 18 wt.%. In a polymer layer comprising a luminescence downshifting compound which is furthest spaced away from the photovoltaic cell comprises a luminescence downshifting compound for at least partially absorbing UV radiation and re-emitting radiation at a higher wavelength. The panel has a layer sequence of a glass layer, the polymer sheet, a photovoltaic cell, an encapsulant layer and a back sheet. EXAMPLE - No suitable example given.