One of the major road blocks to the design and development of new, more efficient solar cells may have been cleared. Users of the Molecular Foundry have developed the first ab initio method – meaning a theoretical model free of adjustable or empirical parameters – for characterizing the properties of “hot carriers” in semiconductors. Hot carriers are electrical charge carriers – electrons and holes – with significantly higher energy than charge carriers at thermal equilibrium.
Since hot carrier thermalization is a major source of efficiency loss in solar cells, and because of the sub-picosecond time scale and complex physics involved, characterization of hot carriers has long been a challenge even for the simplest materials. This work makes it possible to understand how hot carriers lose energy, and therefore, how materials used for photovoltaic cells function.