ABSTRACT
This chapter describes different schemes to overcome limitations of solar energy harvesting. It discusses the conversion of spectral characteristics by the use of luminescent layers and molecules that perform different processes of thermalization, splitting, and fusion of photons to significantly change wavelength of emission. The chapter examines tandem solar cell that combines different semiconductor layers of complementary bandgaps to absorb different portions of solar spectrum for more efficient photon utilization. It reviews the main methods of conversion of sunlight to chemical fuel by application of phototelectrochemical cells and photovoltaic cells combined with catalyst layers. The essential requirement that marks a contrast with electricity-producing photovoltaics is the necessary contact of the system with the active electrolyte in which effective catalysts must carry out the desired reactions. An approach aims at converting a photovoltaic device into a photoelectrochemical cell (PEC) by using the protecting layers to avoid the chemical reaction of the liquid solution with the materials used in the photovoltaic device.
