Abstract: The present invention relates to a collector adapted to concentrate solar energy onto a photoelectric cell comprising in combination at least one glass plate doped with a substance resulting in fluorescence when said plate is irradiated by sunlight, a photoelectric cell being attached to a lateral side of the plate, the other lateral edges of the plate being provided with a reflective coating, said cell having a high efficiency in the range of wavelength of the fluorescent radiation.A plurality of such glass plates can be stacked one upon the other, each doped to absorb at a predetermined region of the spectrum and to fluoresce in a region where a certain photocell is sensitive.A fluorescent dye in a suitable carrier can be applied as a surface layer on such glass plates, and this improves the overall efficiency of the collector.