AbstractDown converter SiNx:Yb3+/SiNx:Tb3+ multilayers are deposited by reactive magnetron cosputtering with the objective of optimizing the interaction distance between Tb3+ and Yb3+ ions to favor a better light management in Si solar cells. Those Si‐based multilayers are developed to be compatible with the Si photovoltaic technology. The deposition parameters are optimized to enhance the emission of the Yb3+ ions in the IR region. The emission efficiency of such multilayer structure is compared with a mixed RE SiNx:Tb3+‐Yb3+ layer evidencing a gain resulting from a better management of the Tb3+ and Yb3+ ions distance. At the end, we integrate the growth of such a multilayer in an industrial Si solar cell process and demonstrate the existence of a frequency conversion effect that is promising for the future increase of the Si solar cell efficiency.