Think solar cells, but broader than that. One application of converting light into useful energy is to break up water into hydrogen and oxygen, basically artificial photosynthesis. Plants do it very well. Technology hasn’t until now. By using very thin layers of gold (measured in nanometers, as in a few atoms thick), and creating the right sandwich, researchers can harvest 85% of light. Make the sandwich just right and the light bounces between them giving the light more opportunities to be absorbed rather than just passing through in the simplest solar cells. Until recently, solar cell efficiency was around 10%. The new technology is being directed towards a version of electrolysis, but can also be used to create solid-state solar cells. If this can be mass produced, solar power may find a significant boost in it’s already impressive competitive advantage over fossil fuels.