Institute of High Pressure Physics

A public defense of the doctoral dissertation of Mateusz Hajdel, M.Sc. Eng., will be held on 15 December 2025 (Monday) at 11:00 a.m. in the seminar room of the Institute of High Pressure Physics, Polish Academy of Sciences, in Warsaw, 29/37 Sokołowska St.

Dissertation title: „Operating principle of wide (In,Ga)N quantum wells grown by plasma-assisted molecular beam epitaxy”

Full text of the announcement

The dissertation and reviews are available here.

The well-known, graphite-like hexagonal boron nitride (hBN) is currently experiencing a major renaissance as an essential material in 2D electronics, an extremely efficient UV emitter, and an excellent neutron detector. To fully explore and exploit the potential of hBN, a top-quality material is required, preferably in the form of a single crystal of a size suitable for research and applications.

At our Institute, we are working on the crystallization of hBN under high pressure. Recent results have been just published in the paper Crystal Growth of hBN from Ni and Ni–Cr Solutions at High N2 pressure, B. Sadovyi, P. Sadovyi, A. Nikolenko, V. Strelchuk, B. Turko, Y. Eliyashevskyy, I. Yahniuk, M. Marocko, J. Eroms, I. Petrusha, S. Krukowski, S. Porowski, and I. Grzegory, ACS Applied Materials & Interfaces 17, 63610 (2025). We describe there the processes and results of hBN crystal growth from B and N solutions in liquid nickel and a Ni-Cr mixture, under a nitrogen pressure of 1000-1500 bar.

The transparent, colorless hBN crystals showed excellent structural quality and homogeneity, confirmed by Raman spectrum mapping. The width of the E_2g Raman peak corresponding to the vibrations of atoms in the plane of the hBN layer did not exceed 8 cm^-1, which is evidence of the very high crystalline quality of the obtained hBN. Analysis of optical absorption spectra confirmed that hBN is a crystal with a skewed energy gap. Increased by a factor of 30-40 as a result of compression, the solubility of nitrogen in metal allowed for the production of crystals significantly thicker (up to 30 μm) than at atmospheric pressure.

In order to further verify the quality of the obtained single crystals, our collaborators from the University of Regensburg exfoliated thin hBN flakes and used these flakes to construct graphene devices. In graphene layers surrounded by hBN layers, spectacularly high mobility of both electrons and holes was obtained, exceeding 21.2 m²·V–1·s–1 at 230 K.

The paper summarizes part of the results of the research project “Long-term program of support of the Ukrainian research teams at the Polish Academy of Sciences carried out in collaboration with the U.S. National Academy of Sciences with the financial support of external partners” Grant No. PAN. BFB.S.BWZ.369.022.2023, entitled “Influence of high N2 gas pressure on crystallization mechanisms and physical properties of h-BN”.

Hydrostatic extrusion (HE) of pure titanium effectively boosts its mechanical strength and wear resistance without the need to add alloying elements such as Al, V or Nb. It strongly refines the microstructure but creates anisotropy due to fibrous grains aligned with the extrusion direction, limiting its use in components subjected to forces perpendicular to these fibers.

A recent study from our Institute addresses this issue by applying equal-channel angular pressing (ECAP) before HE. The Institute of High Pressure Physics (IHPP) PAS developed an ECAP station for room-temperature deformation, avoiding heating that reduces strain hardening. ECAP of titanium at ambient temperature is rare in literature, and combining ECAP with HE for titanium remains largely unexplored. Recent study by M. Kulczyk et al. Using a Combination of ECAP and HE Processes to Produce Isotropic Ultrafine-Grained Titanium Materials 2025, 18, 5194 presents an optimized ECAP + HE process that produces ultrafine-grained/nanocrystalline titanium with isotropic mechanical properties. Structural changes were analyzed using TEM, statistical image analysis, and SEM-EBSD techniques.

Resolving the strong anisotropy in ultrafine-grained titanium unlocks new prospects for its commercial use, especially in medical implants.

Inverse pole figure (IPF) maps of TiGr2 microstructure after hydrostatic extrusion (HE) (a,b) and combined ECAP + HE (c,d) processing.

Today, November 13, 2025, the inauguration of the European Wide Band Gap Semiconductors Pilot Line – Polish Node project took place in the Leonard Sosnowski Auditorium of the Institute of Physics PAS. The event was organized by the Łukasiewicz Institute of Microelectronics and Photonics. The first European-level WBG Pilot Line project meeting took place on October 1, 2025, in Rome.

Today's event officially inaugurates the Polish node within the European Wide Band Gap Semiconductor Pilot Line, implemented as part of the Chips Joint Undertaking.

Two Polish institutes are involved: the Institute of High Pressure Physics of the Polish Academy of Sciences (IHPP PAS) and Łukasiewicz Institute of Microelectronics and Photonics (IMiF). The project's objectives include developing production lines for 4-inch GaN substrates, improvement of existing technologies for epitaxial growth and processing of nitride structures for high-power devices, and advancement of new types of diodes and transistors.

The meeting included a lecture by Professor Tetsuo Narita from Toyota Central R&D Labs and Nagoya University, the symbolic unveiling of a time capsule, and presentations by the project partners.

We are pleased to announce that Prof. Wojciech Knap from the Institute of High Pressure Physics PAS has become a laureate of the 2025 Foundation for Polish Science Prize in the field of mathematical, physical and engineering sciences. This distinction – often referred to as the “Polish Nobel Prize” – is considered the most prestigious scientific award in Poland.

The Prize was awarded for his pioneering development of new methods for detecting, amplifying and generating terahertz waves, which pave the way for ultra-fast wireless communication and a wide range of THz radiation applications in medicine, industry and telecommunications. Prof. Knap’s scientific achievements significantly strengthen Poland’s position among the world leaders in terahertz technology research.

Since 2013, Prof. Knap has been affiliated with the Institute of High Pressure Physics PAS, where he established the Terahertz Radiation Laboratory. On his initiative, the CENTERA Terahertz Research and Applications Center at IWC PAS was created, as well as CENTERA2 operating at the CEZAMAT Centre of the Warsaw University of Technology. These centres conduct advanced basic and application-oriented research on terahertz phenomena, co-financed, among others, by the Foundation for Polish Science.

The official award ceremony will take place on 3 December this year in Warsaw.

We warmly congratulate Professor Knap and the entire team of the Terahertz Radiation Laboratory and CENTERA, and wish them continued outstanding scientific success.

Researchers from the Institute of High Pressure Physics, Polish Academy of Sciences (IWC PAS / Unipress) will take part in the 8th International Symposium on Growth of III-Nitrides (ISGN-8), held at National Cheng Kung University in Tainan, Taiwan, on 9–12 November 2025.

The Institute’s Director, prof. Michał Boćkowski, will deliver an invited lecture in Session S1 “III-N Bulk Crystal Growth,” titled “The Science and Art of GaN Crystal Growth.”

This year ISGN-8 will also inaugurate the Iwińska Award – Best Student Presentation, established in memory of Dr. Małgorzata Iwińska (1985–2024), a brilliant GaN-growth specialist from IHPP PAS. The award—sponsored by IHPP PAS—recognizes excellence among student presenters and commemorates Dr. Iwińska’s scientific achievements and support for young researchers.

We are pleased to announce the 10th Winter Workshop Kalatówki - a unique scientific meeting dedicated to the physics and technology of group-III nitride semiconductors, including InGaN-based laser diodes, LEDs, quantum emitters, and novel optoelectronic devices. It organized on March 15-20, 2026.

The workshop continues the long-standing tradition of informal and inspiring discussions held in the beautiful scenery of the Tatra Mountains. Researchers are invited to share their latest results, exchange ideas, and strengthen collaborations in a relaxed atmosphere of the Kalatówki mountain lodge. As in the previous Workshop editions, attendance is by invitation only.

Topics include:

• Epitaxial growth and processing of III-N structures
• Optical and electrical characterization
• Laser diodes, micro-LEDs, and photonic integration
• Quantum devices and defects in nitrides
• Novel applications in communication, sensing, and metrology