Movies show the fabrication of active layers for organic solar cells by the spontaneous spreading technique. Here, a Petri dish is filled with water serving as a substrate for film formation. The resulting film can be transferred to a device substrate. This method allows the fabrication of novel solar cell architectures by transferring multiple layers on top of each other. The results obtained by the spontaneous spreading method for the fabrication of organic solar cells are described in Chapter 4, 5, and 6 of the thesis.