ABSTRACT
This chapter describes different schemes to overcome the limitations of solar energy harvesting. It discusses the conversion of the spectral characteristics by use of luminescent layers and molecules that perform different processes of thermalization, splitting, and fusion of photons to significantly change the wavelength of the emission. The chapter discusses the tandem solar cell that combines different semiconductor layers of complementary band gaps to absorb different portions of the solar spectrum for more efficient photon utilization. It reviews the main methods of conversion of sunlight to chemical fuel by application of photoelectrochemical cells and photovoltaic cells combined with catalyst layers. In order to improve the harvesting of the energy of the solar photons, one can either transform the incoming spectrum to adapt it to the semiconductor features, as discussed in the following paragraphs, or we can combine several semiconductors toward a better spectral match.
