TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The down conversion layer is formed for down conversion by absorption of photons in a wavelength range of 300-500 and after conversion of photon emission in the wavelength range of 600-900. The luminescent material comprises at least one terbium, erbium and/or other rare earths, luminescent semiconductor nanoparticles or organic dyes. The matrix of the composite material, in which matrix of the luminescent material is embedded, comprises at least one aluminum oxide, silicon dioxide, silicon nitride compound of formula (SixN1-x) (I), silicon carbide compound of formula (SixC1-x) (where x is 0-1) (II), glasses, glass ceramics, polymers, preferably poly (methyl methacrylate), polycarbonate, fluorine polymers and/or Nafion (RTM: Sulfonated tetrafluoroethylene based fluoropolymer-copolymer). The down conversion layer is formed for reducing the reflection of the incident electromagnetic radiation in the wavelength range of 400-700nm, preferably 300-1200nm. The down conversion layer is formed as anti-reflection layer having a spatially constant refractive index, in which the thickness and refractive index of the down conversion layer is configured for antireflection during the operation. The down conversion layer is formed as an index-gradient anti-reflective layer with a refractive index varying spatially, perpendicular to the radiation incident side, which increases the refractive index based on the side facing during operation of the incident radiation towards the base, at least in the central, preferably increases steadily. The refractive index at the side of the down conversion layer facing during the operation of the incident radiation, during arrangement of the down conversion layer on a module glass lies in the area of 1-1.2 up to a larger refractive index of greater than 1.3, preferably about 1.5 or during an arrangement of the down conversion layer on a solar cell lies in the area of 1.5-2 up to a larger refractive index of greater than 2, preferably about 3. The luminescent material is embedded in the particles of the composite material and the spatial change of the refractive index is configured by a change of the particle concentration in the down conversion layer, preferably the particle has a diameter less than 500nm, preferably less than 100nm. The down conversion layer is part of a layer system, which in addition to the down-conversion layer further exhibits layers for antireflection. The layer system is formed as a bragg stack, rugate filter and/or with angle-selective properties, preferably as edge filter. The down conversion layer is formed as a photonic structure, in which the luminescent material is embedded in particles of the composite material, where the particles are arranged in a photonic crystal structure, preferably the particle has a diameter of 50nm-2 mu m, preferably 100nm-1 mu m. The down conversion layer is formed as a sol-gel layer, preferably the luminescent material is embedded in silicon dioxide particles and the luminescent material includes terbium. The down conversion layer is formed as a silicon dioxide layer, in which luminescent material is embedded, preferably the silicon dioxide layer is doped with a luminescent material, preferably with terbium. The photovoltaic element is designed as photovoltaic solar cell for converting incident electromagnetic radiation into electrical energy, where the solar cell has at least one base of a basic doping type and at least one emitter of an emitter doping type, where the emitter doping type is opposite to the basic doping type, and the emitter and base are arranged such that at least in partial regions between the base and emitter a pn junction is formed, where at least one intermediate layer is arranged at a radiation incident side of the base of the down conversion layer, facing during the operation of incident electromagnetic radiation, optionally under the interposition. The down-conversion layer is additionally formed as a passivation layer for reducing the surface recombination of charge carriers, preferably the down conversion layer is arranged directly on the side of the emitter and/or the base facing during operation of the incident electromagnetic radiation. The photovoltaic element is formed as a photovoltaic solar cell module, comprising a multiple of juxtaposed photovoltaic solar cells, where the module on the side facing during the operation of incident electromagnetic radiation has a modular glazing and the down conversion layer is disposed on the modular glazing, preferably on the side of modular glazing facing the radiation, the solar cells formed from above method, preferably all solar cells of the module includes a common down conversion layer.