Multiplying opto-photonic and light-to-electricity converting platform unit for power generation provided on its front face with a protection antireflection coating or layer and provided with an upper electrode layer, said platform unit further comprising: - an upper opto-photonic light managing platform and a multiplying light-to-electricity conversion platform with a low-energy carrier multiplication, wherein - the opto-photonic platform is configured to manage incident light and project it under the form of narrowed sub-bands light spots on each of a series of adapted light-to-electricity dedicated converters of the carrier multiplying light-to-electricity conversion platform lying under the opto-photonic platform, said opto-photonic platform being composed of: - a UV radiation light-to-light down-converter to adjust the UV radiation to a particular sub-band in the visible radiation domain, - a harvesting diffractive grating component provided with an electronic passivation layer and with light splitting means and one or more sub-band light into narrowed sub-band light concentration sub-band converter(s) in order to guide and project each a spot of concentrated narrowed sub-band light on a downstream adjusted light-to-electricity converter, whereas the opto-photonic platform is configured to transpose or convert or concentrat processed photons corresponding to each related energy step of a spectral sub-band spectrally into a narrow sub-band corresponding to a first part of a total multiplication step of the corresponding band span of this sub-band related to a step of energy whereas each narrow bandwidth is so concentrated that it fits into the lowest energy of a corresponding multiplication step, - an IR radiation up-conversion dedicated light-to-light up-converter, - said multiplying light-to-electricity conversion platform being made of several dedicated converters for each narrowed and concentrated spectral sub-band light component, each of said light-to-electricity multiplying converters being adjusted to each related narrowed and concentrated sub-band component part of the incident light spectrum they receive on their own exposured front face,. - an upper opto-photonic light managing platform and a multiplying light-to-electricity conversion platform with a low-energy carrier multiplication, wherein - the opto-photonic platform is configured to manage incident light and project it under the form of narrowed sub-bands light spots on each of a series of adapted light-to-electricity dedicated converters of the carrier multiplying light-to-electricity conversion platform lying under the opto-photonic platform, said opto-photonic platform being composed of: - a UV radiation light-to-light down-converter to adjust the UV radiation to a particular sub-band in the visible radiation domain, - a harvesting diffractive grating component provided with an electronic passivation layer and with light splitting means and one or more sub-band light into narrowed sub-band light concentration sub-band converter(s) in order to guide and project each a spot of concentrated narrowed sub-band light on a downstream adjusted light-to-electricity converter, whereas the opto-photonic platform is configured to transpose or convert or concentrat processed photons corresponding to each related energy step of a spectral sub-band spectrally into a narrow sub-band corresponding to a first part of a total multiplication step of the corresponding band span of this sub-band related to a step of energy whereas each narrow bandwidth is so concentrated that it fits into the lowest energy of a corresponding multiplication step, - an IR radiation up-conversion dedicated light-to-light up-converter, - said multiplying light-to-electricity conversion platform being made of several dedicated converters for each narrowed and concentrated spectral sub-band light component, each of said light-to-electricity multiplying converters being adjusted to each related narrowed and concentrated sub-band component part of the incident light spectrum they receive on their own exposured front face,. - a UV radiation light-to-light down-converter to adjust the UV radiation to a particular sub-band in the visible radiation domain, - a harvesting diffractive grating component provided with an electronic passivation layer and with light splitting means and one or more sub-band light into narrowed sub-band light concentration sub-band converter(s) in order to guide and project each a spot of concentrated narrowed sub-band light on a downstream adjusted light-to-electricity converter, whereas the opto-photonic platform is configured to transpose or convert or concentrat processed photons corresponding to each related energy step of a spectral sub-band spectrally into a narrow sub-band corresponding to a first part of a total multiplication step of the corresponding band span of this sub-band related to a step of energy whereas each narrow bandwidth is so concentrated that it fits into the lowest energy of a corresponding multiplication step, - an IR radiation up-conversion dedicated light-to-light up-converter, - said multiplying light-to-electricity conversion platform being made of several dedicated converters for each narrowed and concentrated spectral sub-band light component, each of said light-to-electricity multiplying converters being adjusted to each related narrowed and concentrated sub-band component part of the incident light spectrum they receive on their own exposured front face,.