"Hönnun ljósgleypniefna til klofnunar vatns í vetni og súrefni byggt á atómbyggingu efnanna" (enskur titill: Atomic-Scale Design of Light Absorbers for Water Splitting). Erindi flutt af prófessor Karsten Jacobsen frá Tækniháskólanum (DTU) í Danmörku. Erindið verður flutt á ensku.
The design of new materials for more efficient production and use of sustainable and clean energy is of utmost importance for the standard of living all over the World the coming years. Efficient utilization of solar energy can take many forms including transforming the energy of the light into heat, electrical energy, or fuels.
In the talk I shall describe computational efforts to idenfity or design new materials for efficient light absorption with particular focus on light-induced splitting of water but also with an eye towards other light absorbing devices like PV cells. The materials have to obey a number of criteria in order to work for water splitting depending on the particular design of the device. We consider in particular stability, including corrosion resistance in water, appropriate bandgap and bandstructure for visible light absorption, and an adequate line-up of band edges to the water redox potential. The fast calculation of bandgaps is still challenging and different approaches to this will be compared. Furthermore the construction of Pourbaix diagrams for estimating corrosion stability will be addressed.
We have considered several classes of materials with most emphasis on the cubic perovskite structure and derivatives like double perovskites and layered perovskites (Ruddlesden-Popper and Dion-Jacobson phases) with 52 different metallic elements and different anions (O, N, S, F). Also some organic perovskites have been considered. Many of these materials are known to exist in Nature but some properties like their bandgaps are not known from experiment.