3. Hybrid perovskite solar cells

3.1 Excitonic solar cells

In these cells, the generation of electrons and holes (electron gaps) under irradiation by photons of sufficient energy (photoelectric effect) takes place in the absorber layer. These charges must be separated and collected. On an insulating substrate, they will recombine, generating photons of lower energy than the incident photons (photoluminescence) and heat (non-radiative recombination). Charge separation is achieved thanks to the selective contacts formed by two other adjacent phases whose energy levels are compatible with those of the absorber. The absorber is thus sandwiched between two other phases (figure 6 ). To recover the electrons, a material with a lower...