Ion implantation and annealing became recently an interesting route to change electrical properties of GaN, enabling for instance to go beyond the epitaxy capabilities in terms of doping. Understanding the process of defect formation seems to be crucial for the contol of the material properties after ion implantation.
Institute of High Pressure Physics invites to an open seminar of prof. Akira Uedono from the Faculty of Pure and Applied Sciences, University of Tsukuba, Japan. The title of his presentation is "Vacancy-type defects in GaN studied by positron anihilation spectroscopy".
The seminar will be held in person atPrymasa Tysiąclecia 98 (seminar room, second floor) in the Institute of High Pressure Physics on Friday, November 24, 2023 at 3:00 pm.
Polarization doping became recently a very attractive alternative to magnesium (Mg) acceptor doping. It offers flexibility of tuning carrier concentration through adjustments in layer thickness and composition gradient. Furthermore, it maintains a stable carrier concentration irrespective of temperature fluctuations that is well-suited for cryogenic device applications.
In the next Thursday UNIPRESS seminar, Muhammed Aktas from Optoelectronic Device Laboratory of our Institute will present laser diodes that implement the polarization doping. He will compare the device performance at room and cryogenic temperatures. We invite you to his talk entitled "Polarization doped P-cladding for InGaN Laser". The abstract can be downloaded here.
The seminar will be held on-line through Zoom platform on Thursday, November 30, 2023 at 15:00. To get the link to join the seminar, please contact us at dyrekcja@unipress.waw.pl
Materials for energy harvesting are recently intensively studied due to the increasing need to substitute fossil fuels. They enable reusing of waste energy directly gained from the environment and convert it to electricity. One of the promising candidates for thermogenerators is Al-doped ZnO (AZO). Thermoelectric properties of this material can be tuned not only with Al doping level but also by its structure.
More on this subject will be presented by Prof. Paolo Mele from College of Engineering, Shibaura Institute of Technology (Japan)at the coming UNIPRESS Seminar on Wednesday October 18, 2023 at 14:00. We invite you to his talk entitled „Nanoengineered Al-doped ZnO thin films for thermoelectric applications”.
The seminar will be held in hybrid mode – in person at the Institute of High Pressure Physics PAS at Prymasa Tysiąclecia 98 (seminar room, second floor), and on-line through Zoom platform.
Nowadays, Global Warming & Energy Crisis is experienced in every country/state. It is a planetary-scale civilization threat, and breakthrough innovative concepts seem to be essential for their overcoming. New generations of energy storage facilities seem to be particularly important. The lecture presents the works of X-PressMatter laboratory (NL10) on 'glassy' batteries for electric energy storage and 'thermal batteries' for 'cold' and 'heat' storage. Both concepts are inherently associated with high pressures, from ~ 50 MPa (500 atm) to ~ 2 GPa. ‘Glassy’ batteries research is related to electrodes composed of nanocrystallites in the amorphous (glass), formed under high pressure and high temperatures. It is the ‘hope’ for extreme durability and avoiding ‘critical resources’, such as Lithium. The barocaloric effect-based ‘thermal batteries’ are related to exploring the latent heat (DH) and entropy (DS) associated with melting/freezing phase transition on compressing and decompressing. The obtained DS are 2-3x higher than the current 'record' – for processing neutral for the natural environment. It can allow the design of qualitatively new heating, cooling, and air conditioning systems. It is worth noting that 1 kg of R134a- type fluids, commonly used in air conditioning, has the same harmful effect on the atmosphere as a TIR truck after 6 months drive..
Prof. Sylwester J. Rzoska from our Institute, Laboratory of Ceramics and Glass, X-PressMatter will give a talk on „The Great Energy Crisis & Global Warming - some innovative solutions based on high-pressure-related R&D” in the coming Thursday UNIPRESS seminar.
The seminar will be held on-line on Thursday, September 21, 2023 at 15:00. To get the link to join the seminar, please contact us at dyrekcja@unipress.waw.pl