Institute of High Pressure Physics

National Science Center (NCN) announced the results of OPUS 26+LAP/Weave for the bilateral projects conducted with partners in Germany. Dr. Grzegorz Muzioł from MBE Laboratory of our Institute received funding for the project „Multi-junction distributed-feedback laser diodes - synergy of high optical power and single-mode operation”.

The project will develop a completely new optoelectronic device - a multi-junction distributed-feedback laser diode (DFB LD), which is shown schematically in Figure 1.

Multi-junction LDs have several pn junctions interconnected with tunnel junctions (TJs). The advantage of this scheme, compared to single junction devices, is that for the same current flow, the recombination occurs in each of the quantum wells (QW). In principle, one can expect an N-fold increase in output power of the multi-junction LD with N sections. This results in differential efficiency (photons per injected electrons) higher than 100%, which comes at the cost of additional voltage required for each section. The DFB grating placed on the surface of the device, as shown in Figure 1, will ensure strong coupling to the optical mode and lasing at only one wavelength – the one that matches the grating.

The demonstration of visible multi-junction DFB LDs will open a new field of GaN-based devices and stimulate new research directions. Abstract of the project is available here.

The project will be conducted in collaboration between Institute of High Pressure Physics Polish Academy of Sciences (IHPP PAS), CEZAMAT Warsaw University of Technology and group of Prof. Ulrich Theodor Schwarz from Technische Universität Chemnitz (TU Chemnitz).

Figure 1. (a) A schematic showing the concept of a multi-junction distributed feedback laser diode composed of three sections interconnected with tunnel junctions (TJ). The third order optical mode is drawn with maxima in the three quantum well (QW) regions. The light propagating in the device couples to the DFB grating that is placed on the surface and ensures lasing in a single mode. (b) Schematics of a band diagram for a LD stack (click to enlarge the Figure).

Institute of High Pressure Physics PAS opens the competition for PostDoc in the NL10 laboratory X-PressMatter to work in the NCN Project: ‘Pressure-formed glass materials for innovative energy storage and conversion’, ref. NCN: 2022/45/B/ST5/0400; Primary Investigator: Prof. dr hab. Sylwester J. Rzoska. Detailed conditions of the competition are given in the attached announcement.

Application deadline: December 15, 2024 at 16:00.

The winning candidate will work on innovative materials for the new generation of batteries, both for electrodes and ‘solid’ electrolytes. A special distinguishing feature of the work is the formation of materials using high pressures and the use of advanced implementations for research using broadband electrical impedance.

More information are available by e-mail: sylwester.rzoska@gmail.com

This Sunday, November 3, will mark the start of the largest conference on nitride semiconductors, the 12th International Workshop on Nitride Semiconductors (IWN 2024).

The conference consists of five thematic symposia: Growth, Characterization/Physics, Optical and Optoelectronics, Electronic Devices, and Nanoscale. The Chair persons of the Growth symposium are Prof. Izabella Grzegory and Prof. Michal Boćkowski from our Institute.

The plenary lecture entitled. “Tunnel Junctions for Novel Nitride Optoelectronic Devices” will be given by Prof. Czeslaw Skierbiszewski, head of the MBE Epitaxy Laboratory of IWC PAN.

Two employees of the Institute have been asked to give invited papers: Prof. Henryk Turski will speak on “Epitaxy of III-Nitride Devices on Opposite Facets of the Same Polar Crystal: New Perspectives in Materials Engineering” and Dr. Tomasz Sochacki will talk about “Morphological Evolution During Bulk GaN Growth”. A number of other IWC PAN employees will also speak at the conference, presenting the results of their work on nitride semiconductors. Prof. M. Boćkowski will also appear as a panelist at the Rump Session entitled. “Future of III-Nitride Power Electronics”.

10th Workshop on Physics and Technology of Semiconductor Lasers was organized this year from 13 to 18 October, 2024 by our Institute in Sopot and chaired by prof. Piotr Perlin. It was a very successful meeting, gathering almost seventy participants with 62 presentations that included 14 invited talks, 29 contributed presentations and 19 posters. Thank you all for the fruitful discussions!

Next 11th Workshop on Physics and Technology of Semiconductor Lasers will be organized in 2026 by Lodz University of Technology, and chaired by prof. Tomasz Czyszanowski. We are all looking forward to it!