 In 2002, he obtained his habilitation from the University of Oldenburg, Germany, for work on the electrical transport properties of semiconductors and interfaces for photovoltaics.Since 2007, Rau is a full professor at the RWTH Aachen and Director of the Institute for Energy and Climate Research at the Forschungszentrum Jülich.Since 2011, he is in addition, the scientific director of the HITEC graduate school at the Forschungszentrum Jülich.