Institute of High Pressure Physics

Vertical GaN power devices are promising candidates for future kV-class power electronics due to the wide bandgap and high critical electric field (EC) of GaN. Vertical architectures provide the possibility of downsizing the devices and increasing their reliability. However, still a few challenges have to be addressed such as selective area doping, Schottky contact formation and drift layer growth.

In the next Thursday UNIPRESS seminar, Kacper Sierakowski from our Institute, the Crystal Growth Laboratory, will present the current state of the art in ion implantation in GaN and summarize the recent progress in the design of Junction Barrier Schottky (JBS) diodes.

The Seminar “Magnesium ion implantation – key technology for GaN power electronics” will be held on Thursday, May 25, 2023 at 15:00 on Zoom platform. To get the link to join the seminar, please contact us at dyrekcja@unipress.waw.pl

The zero resistance and the expulsion of a magnetic field occurring in a superconducting material have huge potential for many practical applications, and seven Nobel prizes have been awarded in the last 100 years. Recently discovered iron-based superconductors (FBS) with high transition temperature (T_c) of 58 K became the second high-T_c-superconducting family after cuprate superconductors. The physical nature and application potential of FBS will be the subject of the next Institute Thursday Seminar.

Dr Shiv J. Singh from our institute, the Laboratory of Superconductors, will introduce the iron-based superconductors and discuss the pressure effects on superconductivity, flux pinning, and vortex dynamics of FBS under ambient and applied conditions, as well as the challenges and current progress.

The Seminar “Review of pressure effects on high-temperature iron-based superconductors” will be held on Thursday, April 27, 2023 at 15:00 on Zoom platform. To get the link to join the seminar, please contact us at dyrekcja@unipress.waw.pl

Can the latest achievements of machine learning (ML) and artificial intelligence (AI) pave a fundamentally new way of doing science? How to teach the algorithm a proper analysis of the huge amounts of data, highlighting anomalies and detecting patterns that humans could never have spotted?

Dr Kazimierz Skrobas from our Institute, the Laboratory of Nanomaterials, will introduce the data processing technique called Machine Learning (ML) and show his material science research examples that employ AI. He will present an application of two simple ML algorithms called Decision Tree and Random Forest to X-ray diffraction data processing will be shown. X-ray diffraction is a basic tool for crystal structure characterization but in many cases analysis is not trivial and extraction of full information is cumbersome. This is true especially for nanostructures where crystal size, crystal shape, and deviation of the atomic structure from perfect periodicity are of particular interest.

The Seminar “Application of Machine Learning to material science domain” will be held on Thursday, March 23, 2023 at 15:30* on Zoom platform. To get the link to join the seminar, please contact us at dyrekcja@unipress.waw.pl

*note that the seminar will start at 15:30, that is 30 min later than usually.

Low resistance p-type conductivity in nitride structures has been for many years one of the most important challenges on the way to the fabrication of efficient light emitters. In fact, the breakthroughs made in this field led to the Nobel Prize in Physics in 2014.

The nitride community has been working on new concepts for GaN p-type doping. One of the recent solutions involves the use of polarization doping effects leading to emergence of strong electric fields in nitride structures.

Prof. Stanisław Krukowski from our Institute, the Crystal Growth Laboratory, will explain the concept of polarization doping and emergence of mobile charge. He will also discuss recent theoretical results in nitride structures.

The Seminar “Fundamentals of spontaneous polarization, piezoelectric polarization and polarization doping” will be held on Thursday, February 23, 2023 at 15:00 on Zoom platform.

To get the link to join the seminar, please contact us at dyrekcja@unipress.waw.pl