NOVELTY - The monolithic photovoltaic tandem cell (1) comprises two photoactive layers (2, 4) consisting of a n-doped emitter and a p-doped area, and an intermediate layer (3), where the first photoactive layer consists of silicon carbide and the second photoactive layer consists of silicon or the intermediate layer is a silicon/carbon mixing layer. The first photoactive layer represents the front side turned to the light and the second photoactive layer represents the back side of the photovoltaic cell and the side turned to the substrate.    USE - Used as monolithic photovoltaic tandem cell.    ADVANTAGE - The monolithic photovoltaic tandem cell can be manufactured with good stability and high efficiency thus enabling better utilization of the spectral range of sunlight.    DETAILED DESCRIPTION - The monolithic photovoltaic tandem cell (1) comprises two photoactive layers (2, 4) consisting of a n-doped emitter and a p-doped area, and an intermediate layer (3), where the first photoactive layer consists of silicon carbide and the second photoactive layer consists of silicon or the intermediate layer is a silicon/carbon mixing layer. The first photoactive layer represents the front side turned to the light and the second photoactive layer represents the back side of the photovoltaic cell and the side turned to the substrate. The n-doped emitter and/or the p-doped area are epitactically deposited to a layer. The thickness of the first photoactive layer is maximum 40 mu m and the silicon/carbon mixing layer has a lattice adaptation on the two photoactive layers through an adapted silicon/carbide ratio. The adaptation of the silicon/carbon ratio of the mixing layer is carried out through the removal of the silicon content and proportional increasing of the carbon content dependent upon the thickness of the intermediate layer and in the direction of the photoactive layer to another photoactive layer. The thickness of the intermediate layer is maximum 10 mu m. The intermediate layer consists of two silicon/carbon mixing layers. A silicon layer deposited on a monocrystalline silicon-wafer or a solar cell fit silicon wafer is used as substrate. The thickness of the photoactive layer is maximum 50 mu m. The n-doped emitter of the first and/or the second photoactive layer is epitactically formed by gas phase-deposition. The intermediate layer and the photoactive layer are formed by a thermal gas phase deposition at 800-1400 degrees C and pressure of 1 mbar to 1 bar. The tandem solar cell is electrically contacted at the front and back side over an interconnection. The photoactive layers are interconnected over individual interconnection. An INDEPENDENT CLAIM is included for a method for the production of a monolithic photovoltaic tandem cell.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of a monolithic photovoltaic tandem cell.    Photovoltaic tandem cell (1)    Photoactive layers (2, 4)    Intermediate layer. (3)