Title: Semiconductor nanostructure formation and doping studied at the atomic scale by cross-sectional scanning tunneling microscopy
Speaker: Prof. Paul M. Koenraad (Eindhoven University of Technology, the Netherlands)
Time: 15:00, Aug. 26, 2010
Venue: Academic Salon, Institute of Semiconductors, CAS
Abstract: Current advanced growth techniques used for the fabrication of semiconductor nanostructures and the study of the optical, electronic magnetic properties of (individual) nanostructures require an atomic scale analysis of their size, shape and composition at the atomic scale. Cross-sectional scanning-tunneling microscopy (X-STM) allows determining these parameters for nanostructures such as quantum dots, rings and nanorods in III/V and II/VI multilayer structures. In the presentation I will show how we have been able to analyze these nanostructures and the role of critical issues such as dot decomposition during capping, intermixing and segregation, As/P exchange and the doping of nanostructures. I will also present some of our latest results on the analysis of single Mn impurities embedded in a self-assembled InAs quantum dot.
About speaker：
Prof. Paul M. Koenraad received his PhD degree from Eindhoven Univ. of Technology in 1990. Then he worked as a senior researcher at IBM-Zurich Laboratories, Switzerland for one year. From 1991 to 2005, he worked as a KNAW-fellow, assistant professor, associate professor at Eindhoven University of Technology. Since 2006 he has worked as a full professor and group leader of Photonics and Semiconductor Nanophysics group, Eindhoven University of Technology. Prof. Paul M. Koenraad has more than 20 years’ experience of research on III-V semiconductor heterostructures and is a leading expert on the application of scanning probe techniques in the study of nanostructures and impurities in semiconductors. His work is presently focused on the spintronic, electronic and photonic properties of individual self-assembled nanostructures and single impurities in a semiconductor material. In 2005 he was awarded the Dutch VICI grant (1.25 Meuro) that allows him to study magnetic impurities and nanostructures in III/V semiconductor materials. He co-authored more than 150 ISI scientific papers and wrote several review papers and book chapters on his research activities. His present research group employs over 40 academic researchers and technicians.