7. New optical processes to increase luminous efficiency

In the previous paragraph, we saw that it is possible to increase the efficiency of solar cells by using luminescent layers that convert the frequencies of incident photons to adapt them to the sensitivity of the solar cell used, but that these processes, to be highly efficient, require the absorption of these layers to be greatly increased and the incident light to be concentrated. The emergence of nanotechnologies is opening up new possibilities in this field. There are two promising avenues: firstly, the introduction of metal nanoparticles coupled to luminescent ions in luminescent layers, and secondly, the nanostructuring of these layers or their coupling with photonic crystals.