Over the course of our exploration of organic solar materials, we found that the synthesis and device fabrication of organic solar cell materials can be grouped into two categories. The first category is the synthesis of small molecular systems with high purity. The second group of organic materials for solar applications is comprised of conjugated polymers and other macromolecular architectures with wide bandgaps. One of the important issues that seem to reappear in estimating the limits of organic materials is the process of exciton diffusion. Finally, we saw two new approaches toward organic and organic–metallic solar cells, which have attracted great attention in the field. The exciting area of singlet exciton fission is a spin-allowed process in which two triplets match the energy of one singlet and subsequently lead to the formation of a triplet pair. The second newer area of organic–metallic solar materials is that of perovskite-based solar cells.