active molecules of aromatic cyclic type for example the number of cores u03c6 of which determine the absorption and emission wavelengths it is also possible to apply on the transparent walls the material forming a cascade of light in the form of a projectable varnish or glass spray for example according to an example the cascades of light as used in the generator of the invention absorb the light in the 300 to 700 nanometer range and re emit at a wavelength of approximately 950 nanometers their effect is conjugated with that of the dichroic coatings acting as a low pass filter making it to possible to cut off radiations above 950 nm for example the modules of the type described in fig1 are advantageously juxtaposable as is illustrated in fig2 for example in order to form large sized structures such as photovoltaic conversion towers the generator 1 of fig2 comprises a juxtaposition of two modules 20 and 21 in that example the photovoltaic cells of each block are arranged in parallel planes noted 23 and 24 respectively in the example of fig2 the walls intended to receive sunlight are transparent covered with a material forming a cascade of light and with a low pass dichroic coating making it possible to cut off radiations above 950 nm for example according to a variant not represented in fig2 the parallel planes containing the photovoltaic cells can be oriented relative to the transparent faces so as to maximize the surface oriented in the direction of insolation in midday on the installation site of the generator fig4 and 5 illustrate two examples of photovoltaic generators or towers formed by juxtaposition of modules such as described for example with respect.