NOVELTY - An organic optoelectronic device (100) e.g. photovoltaic cell, comprises an optical fiber core (102); a radiation-transmissive first electrode (104) surrounding the fiber core; at least one photosensitive organic layer (108) surrounding the first electrode; and a second electrode (110) surrounding the organic layer. The photosensitive organic layer is electrically connected to the first electrode. The second electrode is electrically connected to the organic layer.    USE - As an organic optoelectronic device e.g. photovoltaic cell, useful in a pixel of photoactive apparatus such as solar cell or solar collector; useful for converting photonic energy or electromagnetic energy in form of waves into electrical energy (claimed) for use in lighting, heating, battery charging and powering electrical devices; useful as organic photovoltaic cells, organic light emitting devices (OLEDs) and organic photodetectors.    ADVANTAGE - The organic optoelectronic device e.g. photovoltaic cell, displays increased efficiencies in converting electromagnetic energy into electrical energy. The organic optoelectronic device has a conversion efficiency of greater than 6 (preferably 10)%. The organic optoelectronic device is flexible.    DETAILED DESCRIPTION - An organic optoelectronic device (100) e.g. photovoltaic cell, comprises an optical fiber core (102); a radiation-transmissive first electrode (104) surrounding the fiber core; at least one photosensitive organic layer (108) surrounding the first electrode; and a second electrode (110) surrounding the organic layer. The photosensitive organic layer is electrically connected to the first electrode. The second electrode is electrically connected to the organic layer. The optical fiber core comprises glass optical fiber, quartz optical fiber or plastic optical fiber. The photosensitive organic layer includes a photoactive region having at least one bulk heterojunction between a donor material and an acceptor material. The apparatus further comprises at least one blocking layer (106); and a protective layer (112) surrounding the second electrode. The optical fiber core additionally includes at least one upconversion material; and at least one scattering agent. INDEPENDENT CLAIMS are included for the following:    (1) a method of producing a photovoltaic cell involving providing an optical fiber core; disposing a radiation-transmissive first electrode on a surface of the core; disposing at least one photosensitive organic layer in electrical communication with the first electrode; and disposing a second electrode in electrical communication with the organic layer;    (2) a photoactive apparatus comprising at least one pixel containing at least one photovoltaic cell having an optical fiber core surrounded by radiation-transmissive first electrode, photosensitive organic layer and second electrode in a sequential manner;    (3) a method for converting photonic energy into electrical energy involving receiving radiation along longitudinal axis of the optical fiber core; transmitting the radiation into the photosensitive organic layer through the radiation transmissive first electrode; generating excitons in the organic layer; and separating the excitons into electrons and holes at the heterojunction in the organic layer; and    (4) a method for converting electromagnetic energy in the form of waves into electrical energy, involving receiving an electromagnetic wave; and guiding the electromagnetic wave to transmit radiation into the photosensitive layer.    DESCRIPTION OF DRAWING(S) - The figure shows a cut-away view of an optoelectronic device having a fiber structure.    organic optoelectronic device (100)    optical fiber core (102)    radiation-transmissive first electrode (104)    exciton blocking layer (106)    photosensitive organic layer (108)    second electrode (110)    protective layer (112)    external metal contact. (114)