Enhancing Silicon Solar Cell Efficiency by Modifying the Solar Spectrum

Two approaches can be followed to reduce thermalisation and transmission losses in solar cells and thereby better exploit the solar spectrum. Firstly, modification may be done to lower energies, which can be via down-conversion, where one high energy photon is split into two or more low energy photons, or photoluminescence, where photons are shifted into different wavelength regions. Secondly, modification may be done to higher energies using up-conversion, where two or more low energy photons are combined to form one high energy photon. In this paper, the state of the art of these methods and the suitability of materials available today for application to silicon solar cells are presented