As renewable, ecologically and biologically unobjectionable energy becomes more and more important, we decided to create semiconducting biofilms for solar cell applications. Curli fibers constitute the key element, serving as a scaffold for the growth and stabilization of zinc oxide and titanium dioxide nanoparticles along these fibers. We worked on the optimization of the structure and thickness of the hybrid layers. Absorbing molecules such as organic dyes and fluorescent proteins are added to this initial system to expand the spectral range. The result of our research may pave the way to a novel class of solar panels mainly fabricated by living cells, which can lower the overall costs.