Prof. Jef Poortmans received his degree in electronic engineering from the Catholic University of Leuven, Belgium, in 1985. He received his PhD degree in June 1993. He joined the newly built IMEC in Leuven where he worked on laser recrystallization of polysilicon and a-Si for SOI-applications and thin-film transistors. Afterwards he joined the photovoltaics group, where he became responsible for the group advanced solar cells. Within this frame he started up the activity about thin-film crystalline Si solar cells at IMEC and he has been coordinating several European Projects in this domain during the 4th and 5th European Framework Program. In 2003, he became cluster coordinator of European projects in the latter domain. At the moment, he is scientific director photovoltaics at IMEC. Prof. Poortmans has authored or co-authored nearly 350 papers that have been published in Conference Proceedings and technical journals. He has written 4 book articles, two of which are dealing with the properties and applications of strained SiGe-alloys whereas the other two are in the field of photovoltaics. He is Scientific Editor of a Book on thin-film solar cells and has been acting as co-organizer of several thin-film solar cell symposia in the frame of the E-MRS.