NOVELTY - Tandem photovoltaic system (100) comprises anode (170); cathode (110); a recombination layer (140) between anode and cathode, and containing a semiconductor material; a first photoactive layer (130) between the cathode and the recombination layer; and a second photoactive layer (150) between the anode and the recombination layer.    USE - As a photovoltaic cell for transferring energy in the form of light into energy in the form of electricity.    ADVANTAGE - Recombination layer are prepared by using a solution process that can be readily used in a continuous roll-to-roll process. Such a process can significantly reduce the cost of preparing the photovoltaic cell. The photoactive layer can include a low band gap electron donor material, such as polymer having an absorption wavelength at the red and near infrared (IR) regions (e.g. 650-800 nm) of the electromagnetic spectrum, which is not accessible by most other conventional polymers. When such a polymer is incorporated into a photovoltaic cell together with conventional polymer, it enables the cell to absorb the light in this region of the spectrum, thus increasing the current and efficiency of the cell. The first and second photoactive layers have different band gaps. Light not absorbed by one photoactive layer are absorbed by another photoactive layer. This increases the efficiency of the photovoltaic cell.    DETAILED DESCRIPTION - A tandem photovoltaic system (100) comprises anode (170); cathode (110); a recombination layer (140) between the electrodes, and containing a semiconductor material; a first photoactive layer (130) between the first electrode and the recombination layer; and a second photoactive layer (150) between the second electrode and the recombination layer. The system further comprises a hole carrier layer (120) between the first photoactive layer and the cathode, and a hole blocking layer (160) between second photoactive layer and anode. The recombination layer is disposed on the photoactive layer using at least one process selected from solution coating, ink jet printing, spin coating, dip coating, knife coating, bar coating, spray coating, roller coating, slot coating, gravure coating, and screen-printing.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of the tandem photovoltaic cell.    photovoltaic system (100)    cathode (110)    hole carrier layer (120)    photoactive layer (130)    recombinant layer (140)    photoactive layer (150)    hole blocking layer (160)    anode (170)    external load. (180)