Title:
Understanding the electronic structure and improving the stability of metal halide perovskites for optoelectronics.

Speaker: Shuxia Tao (CCER)
Time: June 27, 2019, 10:00–11:00
Location: Differ, Alexander-zaal

Metal halide perovskites has attracted enormous attention in the scientific community recently, due to breakthroughs in perovskite optoelectronics, mainly in photovoltaics and LEDs. Despite great progress have been made in their use in perovskite solar cells and perovskites LEDs, fundamental understanding of their unique optoelectronic properties and their instability are still missing. Such questions include: why their band gaps are tunable; what is the origin of the variations in the energy levels when their composition is changed; why some compounds are more stable than others; how to stabilize the compounds.

We, Computational Materials Physics group, focus on addressing such fundamental questions by using Density Functional Theory calculations and several other theoretical tools. In this talk, I will present two of our recent publications, giving an overview of our progress in answering such questions. I will also give an outlook of what are our next challenges and what types of computational methods we are going develop/use to meet our new challenges.

References
1
. S. Tao, I. Schmidt, G. Brocks, J. Jiang, I. Tranca, K. Meerholz, S. Olthof, Absolute energy level positions in tin and lead halide perovskites, Nature Communications, 10, 2560 (2019).
2. N. Li, S. Tao, Y. Chen, X. Niu, C. Onwudinanti, G. Brocks, Q. Chen, H. Zhou et al, Immobilizing cations and anions for stable halide perovskite solar cells through chemical bonding enhancement with fluorides, Nature Energy, 4, 408–415 (2019).

The CCER seminars are aimed at researchers interested in computational approaches to (energy) research. The seminar is small-scale, typically 15 participants, and interactive, offering lots of room for discussion. If you don't have access to the DIFFER building but would like to attend, just This email address is being protected from spambots. You need JavaScript enabled to view it. .

Title:
Dissemination of Low-Temperature Plasma Data: a Progress Report.

Speaker: Jan van Dijk (TU/e Applied Physics, Elementary Processes in Gas Discharges)
Time: May 23, 2019, 10:00–11:00
Location: Differ, Alexander-zaal

Microwave-driven plasma reactors are among the most promising devices for the production of value-added chemical compounds from greenhouse gases such as carbon dioxide. A drawback (or rather: a challenge) of the regime in which such plasmas operate, is the bewildering chemical complexity that one has to deal with.

Title:
Machine Learning as a Tool in Physics.

Speaker: Vianney Koelman (CCER)
Time: May 09, 2019, 12:40
Location: TU/e: Flux 1.02

Machine learning is witnessing a turbulent development in all of science and technology. While machine learning as a tool in data analysis has already developed a history also in physics, we now see methodologies and algorithms being developed that open up the opportunity for machine learning being applied to scientific discovery itself. Following a didactical intro to machine learning, this talk will focus on machine learning as a tool in high-throughput simulations for scientific discovery. A few applications related to energy technology will be touched upon.

Title:
Modeling of electrochemical interfaces from an experimental viewpoint.

Speaker: Anja Bieberle (DIFFER)
Time: Apr. 18, 2019, 10:00–11:00
Location: Differ, Alexander-zaal

Electrochemical interfaces are the heart of many alternative, sustainable energy applications. They are determining the efficiency and the overall performance. However, in most cases we do not know what processes take place at the interface and which processes are limiting the performance. Experimental electrochemical measurement methods cannot measure mechanisms or species directly. Analysis methods, such as equivalent circuit fitting for electrochemical impedance data, do not allow to link the electrochemistry directly to the measurement data.

In this talk, we introduce the audience to this dilemma with the case study of photo-electrochemical water splitting. We show most recent electrochemical, experimental results on metal oxide – electrolyte interfaces and show the limitations of experimental studies in analyzing the limiting processes at the interface. We then introduce our new modeling approach that allows us simulating electrochemical data (current – voltage, electrochemical impedance) directly from an electrochemical model. We compare the simulated, electrochemical data to experimental data and show that we can even simulate data which is experimentally not available, but highly desired.

The CCER seminars are aimed at researchers interested in computational approaches to (energy) research. The seminar is small-scale, typically 15 participants, and interactive, offering lots of room for discussion. If you don't have access to the DIFFER building but would like to attend, just This email address is being protected from spambots. You need JavaScript enabled to view it..