Alexander Colsmann studied physics at the Ludwig-Maximilians-Universität Munich, where he received his diploma in 2003. He worked on his diploma thesis "Light emission and transistor effect in organic semiconductors" in the group of Prof. Jochen Feldmann. In 2003 he joined the Optoelectronics group of Prof. Uli Lemmer at the University of Karlsruhe. In 2008 he was awarded his PhD for his thesis "Charge carrier transport layers for efficient organic semiconductor devices". Since then he has been leading the organic photovoltaics research group at the Light Technology Institute at the Karlsruhe Institute of Technology (KIT). In 2012 the German Federal Ministry of Education and Research (BMBF) awarded a 4.3 Mio. Euro early career researcher grant to Alexander Colsmann that is dedicated to the research on organic tandem solar cells. Further research interests include semi-transparent solar cells for building integration, organic light emitting diodes (OLEDs), printed electronics, polymer electrodes, charge carrier transport layers, electrical doping of organic semiconductors, copper indium diselenide (CIS) and perovskite solar cells.