Institute of High Pressure Physics

We are pleased to inform you that our colleague from laboratory NL-12, Dr. Piotr Kruszewski, will represent our Institute at the ICDS-33 conference - 33rd International Conference on Defects in Semiconductors, which will take place from September 14 to 19, 2025, in Shanghai, China. ICDS conference is one of the most prestigious international conferences dedicated to defect research in semiconductors, and the first conference of this series was initiated in 1959 in Gatlinburg, Tennessee, USA.

A significant honor for our Institute is the fact that Dr. Piotr Kruszewski will deliver two oral presentations in Shanghai. The first one is focused on defect studies in Al_xGa_1-xN layers and is titled "On the origin of the electrically active defects E1 and E3 in GaN and dilute Al_xGa_1-xN films grown on Ammono-GaN substrates" while the second presentation addresses defects in gallium oxide (Ga₂O₃) and the influence of an electric field on the defect properties Ec-0.18 eV in crystals grown by the Czochralski method. The full title of this paper is "The electric field influence on EC-0.18 eV electron trap level in (100)-oriented β-Ga₂O₃ crystals grown by the Czochralski method"

More information about the conference, as well as the detailed program, can be found at https://www.icds2025.org/

As a result of the SONATINA 9 competition, the National Science Centre has qualified for financing the research project of dr. inż. Artur Lachowski from our Institute. The project is titled "Optimizing the epitaxial growth of niobium nitride for superconducting electronic applications" and will be realized in part in the Leibniz-Institut für Kristallzüchtung (IKZ) in Berlin, Germany.

The SONATINA grant provides the funds necessary to cover all project expenses and secure the full-time employment of the PI at a Polish research centre. The PIs are also required to plan and complete a fellowship at a renowned foreign research centre of their choice.

More about the SONATINA 9 competition and the results here while the project abstract is available under this link..

Researchers from our Institute used advanced ab initio simulations to unravel how atoms bond in key semiconductor materials like BN, AlN, GaN, InN, and graphene. The calculations confirmed that the valence band of GaN is divided into two separate subbands. The upper subband of GaN is composed of gallium sp and nitrogen p orbitals, while the lower subband consists of metal d and nitrogen s orbitals. Calculation of overlap integrals allowed to determine the bond order in tetrahedrally coordinated semiconductors. According to these results, bonding occurs between resonant p-states of nitrogen and sp³-hybridized metal orbitals in tetrahedral nitrides, allowing tetrahedral symmetry to be maintained. A similar resonant bonding mechanism is observed in hexagonal BN, where the p orbitals of nitrogen create three resonant states necessary for maintaining the planar symmetry of the lattice. BN bonding differs from that in graphene, where carbon states are fully sp²-hybridized. Additionally, π-type bonds in graphene have no ionic contributions, which leads to the formation of Dirac states with linear dispersion close to the K point, closing the band gap

Understanding these nuanced bonding mechanisms refines our fundamental picture of how these semiconductors and 2D materials behave and could directly impact the design of next-generation optoelectronic devices.

The publication is available in Open Access: Ab Initio Elucidation of the Nature of the Bonding of Tetrahedral Nitrides (BN, AlN, GaN, and InN), Hexagonal BN, and Graphene Paweł Strąk, Konrad Sakowski, Pawel Kempisty, Izabella Grzegory, Agata Kaminska, Stanislaw Krukowski. Materials 2025, 18, 2875.

Figure: The electronic properties of bulk wurtzite gallium nitride (GaN). The panels represent, from the leftmost: band diagram, projected density of states (PDOS) of the Ga (left) and N (right) atoms.

The International Conference on Nitride Semiconductors ICNS-15 has just finished with a great success. ICNS-15 was held in Malmö in Sweden from July 6-11, 2025. The conference featured 881 scientific papers, 57 of which were presented by polish researchers. Our team - 21 people from the Institute of High Pressure Physics - presented 33 scientific papers.

We had a Plenary Speaker – prof. Michał Boćkowski, and three invited talks – Dr Anna Kafar, Prof. Paweł Kempisty and Prof. Henryk Turski. Our employees delivered also 7 contributed talks (oral presentations) and 22 poster presentations. Prof. Michał Boćkowski was a panelist in the Rump session "kV Nitride Power Devices: Challenges and Technologies”. We also served as moderators of the individual sessions.

The list of the all presentations by Institute's employees is available at the link.

Researchers from the Institute of High Pressure Physics were actively involved in the organization and had numerous scientific contributions. The ICSN-15 conference was chaired by Vanya Darakchieva, Lars Samuelson and Piotr Perlin. Prof. Tadek Suski was the Honorary Chair. Prof. Izabella Grzegory was among the Program Co-chairs, supporting Åsa Haglund, the Program Chair. Dr Anna Kafar was a panelist in “Women in Nitrides - diversity and inclusion” event.

Special congratulations to the young scientists on their Awards! Muhammed Aktas from the Optoelectronic Devices Laboratory NL15 received the award for the best poster presentation “Low-Temperature Characteristics of PolarizationDoped Nitride Emitters”. Congratulations!