Fractal-like ray trajectories traced in three-dimensional array of photoelectrochemical cells

Underwater spherical photoelectrochemical cells aligned in three-dimensional electrolyte space convert injected sunlight into driving force for water splitting, which is analysed by a model calculation and verified in experiments. Sunlight is well absorbed via a number of bounces on Si, and trajectories of its rays are in a fractal-like scale-free system. Similar systems are applicable to general photoelectrochemical cells.