Michael Rienäcker received the Diploma degree in power systems engineering from Technische Universität Clausthal, Clausthal-Zellerfeld, Germany, in 2014, concentrating on the surface science of gallium phosphide on silicon heteroepitaxy. Since 2015, he has been working toward the Ph.D. degree with the Institute for Solar Energy Research Hamelin, Emmerthal, Germany. He has been developing and characterizing carrier-selective polysilicon on oxide junctions for interdigitated back contact and tandem solar cells.