Opto-electronic unit to be used as a photovoltaic solar sensor composed of an opto-photonic platform for light-harvesting dedicated to solar light and of at least one light-to-electricity associated photoconverter characterized in that the opto-photonic platform has on its front face receiving the incident light, a specific diffractive grating incorporating micro- or nano-structures that are slanted and modulated by their height, slant, thickness and spacing, wherein the height, the slanting angle, the thickness and the spacing of the said micro- or nano-structures are determined on the basis of the incident light wavelengths in order to harvest the total energy of the incident light, and wherein the micro- or nano-structures are composed of a plurality of slanted ribs, wherein the slanted ribs are modulated in order to process a polychromatic radiation and wherein the slanted ribs have a height ranging between 0.3 and 3 micrometer and are spaced of 100 and 600 nanometers between two successive ribs characterized in that the said micro- or nano-structures are implemented in the material of a planar substrate or on or in one or several of its layers, and further characterized in that on or under these micro- or nano-structures are located photonic converters (13, 14) that realize the spectral conversion by emitting only a visible or near infrared spectral sub-band from another visible or invisible part of the incident light, each one of these photonic converters (13, 14) operates with incident ultraviolet or infrared light and illuminates a photoconversion unit or several dedicated photoconverters of the solar sensor, wherein at least one photonic converter is adapted to convert ultraviolet radiation and at least one photonic converter is adapted to convert infrared radiation, and characterized in that the light-to-electricity photoconversion unit or the several photoconverters are dedicated for a spectral sub-band belonging to the visible and near infrared part of the solar light spectrum coming from the opto-photonic platform. the opto-photonic platform has on its front face receiving the incident light, a specific diffractive grating incorporating micro- or nano-structures that are slanted and modulated by their height, slant, thickness and spacing, wherein the height, the slanting angle, the thickness and the spacing of the said micro- or nano-structures are determined on the basis of the incident light wavelengths in order to harvest the total energy of the incident light, and wherein the micro- or nano-structures are composed of a plurality of slanted ribs, wherein the slanted ribs are modulated in order to process a polychromatic radiation and wherein the slanted ribs have a height ranging between 0.3 and 3 micrometer and are spaced of 100 and 600 nanometers between two successive ribs characterized in that the said micro- or nano-structures are implemented in the material of a planar substrate or on or in one or several of its layers, and further characterized in that on or under these micro- or nano-structures are located photonic converters (13, 14) that realize the spectral conversion by emitting only a visible or near infrared spectral sub-band from another visible or invisible part of the incident light, each one of these photonic converters (13, 14) operates with incident ultraviolet or infrared light and illuminates a photoconversion unit or several dedicated photoconverters of the solar sensor, wherein at least one photonic converter is adapted to convert ultraviolet radiation and at least one photonic converter is adapted to convert infrared radiation, and characterized in that the light-to-electricity photoconversion unit or the several photoconverters are dedicated for a spectral sub-band belonging to the visible and near infrared part of the solar light spectrum coming from the opto-photonic platform.