The European Union (EU) Revised Renewable Energy Directive 2023/2413/EU states the need of advancing renewable energy sources to meet the commitments of the Paris Agreement while keeping the EU a global leader in renewables. Among the existing renewable energy technologies, photovoltaics are one of the most mature, promising to reach a worldwide production of 8,519 GW by 2050. Silicon-PVs (Si-PVs) are the most advanced approach to reach the above goal at low costs. However, they still face the problem of thermalization, an energy loss mechanism by which the excess energy of the absorbed photons with respect to the Si band gap is lost. BioSinFin will tackle this issue developing the first bioinspired photomultiplier coating based on singlet fission, a multiple exciton generation process. Here, singlet-fission active chromophores and red-emitting materials are bioconjugated to protein scaffolds with nm precision and used to fabricate a coating to sensitize Si solar cells promising up to an additional 5% to the absolute power conversion efficiency of commercial Si PVs (i.e. about 25% improvement) using a low-cost and sustainable coating, leading a revalue of Si-PV market of up to 15%. This multi-photon protein family and its respective coatings will allow to realize a low-cost, sustainable, environmentally friendly, and highly performing new generation of multi-photon low-energy bio-hybrid emitters of great interest for photonics with a final proof on overcoming thermalization in silicon solar cells, helping the EU to fulfil the Revised Renewable Energy Directive.