The solar photovoltaic photoconverter unit (1) comprises a light processing opto-photonic platform (2) realized by at least one transparent substrate (8) is having on, at least one, of its faces a digital diffractive grating constituted by slanted ribs (11) that are modulated to harvest a maximum of solar light at any angle of incidence to split it into several spectral sub-bands, to guide and to concentrate individually every one of these spectral sub-band, toward a separate output of the opto-photonic platform (2) for allowing its exploitation by a light-to-electricity conversion unit (3) that will have by optimization a grate overall conversion efficiency. The opto-photonic platform (2) also includes photonic converters (13) and (14) converting ultraviolet light into visible light and also infrared light in visible light for a better exploitation of the energy present in the solar light and so increasing the light to electricity conversion. The solar photovoltaic photoconverter unit (1) comprises also a light-to-electricity converter unit (3).