In 2012, the development of dye-sensitized solar cells took an unexpected turn as a result of the breakthrough efficiencies on solid-state DSSC's using perovskite-sensitization (Lee et al. Science 338, 643, 2012; Kim et al. Scientific Reports 2: 591, 2012). Such organolead-halide-perovskite-based solar cells, called Perovskite solar cells, have since then attracted significant interest. The research activities are already massive and progress is fast with >25% conversion efficiencies on cell level. These activities have in fact opened up a new research area resulting in a continuous flow of new possibilities.