Institute of High Pressure Physics

In the latest paper "Deep-level point defects at Ga sites in dilute Al_xGa_1−xN alloys" our colleague, Dr. Piotr Kruszewski, along with collaborators, presented new evidence indicating that the electron trap E1 in Al_xGa_1−xN layers - and likely also in GaN - is associated with a point defect located in the gallium sublattice, rather than the nitrogen sublattice, as was commonly believed. Additionally, based on theoretical calculations (Heyd-Scuseria-Ernzerhof - HSE), it was proposed that the donor responsible for the electronic level of the E1 trap is either carbon or molybdenum, corresponding to C_Ga(0/+) or Mo_Ga(0/+), respectively.

The paper has been highlighted as the Applied Physics Letters Editor's Pick and is available here: https://doi.org/10.1063/5.0272389

At the upcoming EMRS Fall Meeting 2025, in Symposium I - Frontiers of imaging and spectroscopy in transmission electron microscopy, dr hab. inż. Julita Smalc-Koziorowska will present an invited paper entitled. "Revealing defects in nitride semiconductor structures in TEM".

The 2025 Fall Meeting of the European Materials Research Society (E-MRS) will take place from September 15 to 18, 2025 at the main campus of the University of Technology in Warsaw (Poland) and will consist of 23 parallel symposia with invited speakers, oral and poster presentations assorted by one plenary session to provide an international forum for discussing recent advances in the field of materials science.

One of the most formidable barriers in development of nitride-based optoelectronic devices: laser diodes (LDs) and light emitting diodes (LEDs) is high resistance of the metal/p-type nitride contact. The present date solutions are mostly based on Ni/Au contact still they are far from satisfactory. The situation requires basic investigations of the contact nature and technical implementation of new designs. Researchers from IHPP PAS applied complex ab initio and drift-diffusion calculation to elucidate contact nature. The results obtained include:

• elucidation of basic nature of the contact,
• evidence that in any metal/p-type GaN contact there exist tunneling barrier,
• explanation of the role of oxygen-ambient annealing during formation of the Ni-Au contact,
• new design, based on multilayer arrangement of deep acceptors, to achieve low resistance contact.

These results were published in the paper in Electronics vol. 14, p. 3309 (2025): Fundamentals of Metal Contact to p-Type GaN—A New Multilayer Energy-Saving Design Konrad Sakowski, Cyprian Sobczak, Pawel Strak, Stanislaw Krukowski

This study opens a new possibility of application of the new design by implantation formation of the low resistance electric contacts in the near future.

The 8th International Workshop on Ultra-Wide Bandgap Materials and Devices (IWUMD 2025) will be organized on September 21-24, 2025 in Wrocław, Poland. It will summarize and discuss the latest advances in wide bandgap semiconductor technologies.

Institute of High Pressure Physics PAS will contribute with an oral presentation of Bohdan Sadovyi “Characterization of hBN Crystals Grown from Pure Ni-Based Solution at 1.5 kbar N₂ Pressure via Application-Focused Testing” and poster presentation of Robert Czernecki “UVA laser with a thick single AlInGaN quantum well”.

Detailed program and all other information about the IWUMD 2025 can be found here: https://iwumd2025.pwr.edu.pl/

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/