Abstract: Silicon and silicon-based materials are among the important modern materials with application in many fields of technology from electronics to energy materials. For some applications, for example the use of Si in Li-ion batteries, nanometer-sized dimensions are required. A cost-effective, environmentally sustainable, scalable, and versatile formation of functional Si films and materials is therefore of large interest. In this work, we report on the electrodeposition of amorphous silicon-based films onto planar and onto nanoporous copper substrates using different organic electrolytes. The morphology and composition of the Si-based coatings are dependent on the solvent used for electrodeposition. Acetonitrile, as a low viscosity solvent, leads to the faster formation of thicker, mostly metallic, and homogeneous electrodeposited Si films. Propylene carbonate, a higher-viscosity solvent generates thinner and more heterogeneous coatings. The Si electrodeposition presented in this work could be transferred onto other complex substrate morphologies, with potential applications in the fields of heterogeneous photocatalysis or energy storage. Graphical Abstract: [Figure not available: see fulltext.].