Short course 1:
Modulation and noise of semiconductor lasers
Lecturer: Dr. Richard Schatz, KTH, Stockholm
Abstract: The directly modulated semiconductor laser (DML) is a power efficient and cost efficient optical transmitter for datacom applications. Using multilevel modulation, the information capacity is determined by both the modulation bandwidth and noise. Low noise is also important in coherent communication systems and interferometric applications.
This mini course gives a theoretical introduction to modulation and noise of semiconductor lasers. Key parameters and design rules will be identified. Different types of semiconductor lasers (FP, DFB, DBR, VCSELs) and modulation formats (OOK, PAM-4, DMT) will be presented. We will also discuss how the optical cavity can be designed to further enhance the bandwidth via detuned loading, photon-photon resonance and chirp to intensity conversion. Finally the course will include a review of recent state-of-the-art results on high speed DMLs.
Biography: Richard Schatz (Ph.D. 1995) has since 1987 conducted research on the modeling, design and characterization of fiber-optical transmitters (edge emitter lasers, VCSELs and modulators) and links, for on-off keying and multilevel modulation formats at Royal Institute of Technology (KTH), Stockholm. He is also the developer of the laser design software LaserMatrix.
Short course 2:
Single crystals and epilayers of oxide semiconductors: growth technology and properties
Lecturer: Prof. Roberto Fornari, Università di Parma, Italy
Abstract: This lecture will briefly outline the state of the art of the growth technology of semiconducting oxide single crystals and epilayers. The focus will be on metal-sesquioxides (Ga2O3, In2O3, Al2O3 and relevant alloys), as there is an increasing interest on these materials, which offer novel properties and applications with respect to traditional elementary and compound semiconductors, in particular higher bandgap and breakdown voltages.
It will be shown that the growth of bulk crystals is a challenging task because of the very high melting point, which may reach or even go beyond 2000 °C; secondly, a thermal decomposition of the growing crystal and melt may occur, which imposes the adoption of an oxidizing atmosphere and precautions to prevent damages to crucible and other parts of the growth equipment; third, the severe thermal gradients may result in twins or even cleavage or crack of the growing crystal.
Both MBE and MOVPE have successfully been applied to deposition of high-quality metal-sesquioxides films, but also HVPE and Mist-CVD proved to be effective methods for the preparation of thick layers or special polymorphs of the oxide compounds. The lecture will review merits and drawbacks of the different epitaxial approaches.
Finally, a survey of the structural, optical and electrical properties of this class of oxide semiconductors will be presented.
Biography: Roberto Fornari is a physicist and presently Full Professor of Condensed Matter Physics at the University of Parma (Italy), where he also serves as Vice-Rector for Research.
From 1981 to 2003 he worked as research scientist at the Institute of Materials for Electronics and Magnetism (IMEM) of the Italian National Research Council. From 2003 to 2013 he was director of the Leibniz Institute for Crystal Growth (IKZ) in Berlin and professor at the Physics Dept. of the Humboldt University Berlin. In September 2013 he accepted a call from the University of Parma and moved back to Italy.
His research activity has mainly been focused on semiconductors: III-V compounds, nitrides, wide bandgap semiconducting oxides. He authored/co-authored about 170 papers in international journals and about 60 papers in conference proceedings, ten patents and different chapters on crystal growth and properties of technologically important materials. He has edited books and proceedings on crystal growth and materials science, and is currently member of the editorial board of J. Crystal Growth, Cryst. Res.Technol., J. Optoelectronics and Advanced. Materials. He chaired twelve international conferences and four international schools.
He served in numerous scientific bodies and commissions: from 2010 to 2016 he was President of the International Organization for Crystal Growth (IOCG), he served in the Executive Committee of the E-MRS during 2011-17, and chaired the Crystal Growth Section of the Italian Crystallographic Association during 2000-03.
Short course 3:
Wide bandgap power devices: device strategies exemplified with 4H-SiC and GaN
Lecturer: Prof. Mietek Bakowski, RISE, Sweden
Abstract: This mini-course will give an application perspective on wide bandgap power semiconductor devices, from system benefits to devices types and material and technology trends. Important user aspects, such as device and system robustness and reliability, are discussed. Today, the most mature of the wide bandgap materials is 4H –SiC and most examples in the course will be related to power devices made from this material.
Biography: Mietek Bakowski has a lifelong experience of semiconductor power devices, for 25 years focused on wide bandgap semiconductor power devices with an emphasis on 4H-SiC devices. He has extensive teaching experience and served as adjunct professor at the Royal Institute of Technology KTH. He is now affiliated with Rise, Research Institute of Sweden.
Short course 4:
2D Materials and devices
Lecturer: Dr. Zhenxing Wang, AMO GmbH, Aachen, Germany
Abstract: In the course “2D material and device”, basic electrical properties of graphene will be first introduced, followed by the devices that has been so far realized with graphene, such as diodes, transistors, sensors, etc. as well as the circuits based on these devices. In details the engineering process issues such as the interface treatment, transfer and contact resistance will be explained from basic to the state-of-the-art. A discussion will follow to see the rational route to integrate graphene into the current device platforms, e.g. CMOS lines. A minor glance on other 2D materials such as MoS2 will also be part of the course.
Biography: Dr. Zhenxing Wang is a senior scientist at AMO GmbH. He obtained his PhD degree in 2012 from Peking University in China. From 2014 he has been with AMO, where he is responsible for development of graphene based electronics, especially for high frequency applications. He is principle investigator in different German national projects on graphene and 2-dimensional materials based devices, such as HiPeDi and MOSTFLEX funded by the DFG. He is involved as key researcher in different EU-projects including the Graphene Flagship, the FTI project G-Imager, and the FET-Open project WiPLASH. He is (co)-author of >50 papers with total citation >2000; his h-index is 21.