Title: Towards efficient organic thermoelectrics: the interplay between theory and experiment.

Speaker: Jan Anton Koster (University of Groningen)
Time: Dec. 17, 20201, 10:00–11:00
Location: Online (MS Teams)

Koster’s research group is part of the Photophysics and Optoelectronics research unit at the Zernike Institute for Advanced Materials, University of Groningen. The group studies the physics of novel semiconductors and devices. The group’s website may be found at https://www.rug.nl/research/zernike/photophysics-and-opto-electronics/koster-group/

The group is also the driving force behind SIMsalabim: A 1D drift-diffusion simulator for semiconductor devices (LEDs, solar cells, diodes, organics, perovskites). SIMsalabim can be used to simulate current-voltage (JV) characteristics of semiconductor devices. It includes the effects of generation, recombination and trapping of electrons and holes, the effect of ions and dopants, and self-consistently solves the electric field that results from all charged species. More on this may be found at the group’s GitHub page: https://github.com/kostergroup/SIMsalabim

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 would like to attend, just This email address is being protected from spambots. You need JavaScript enabled to view it. so as to receive the MS Teams meeting link.

Title: Unified thermodynamic theory for light-induced phase separation in mixed halide perovskites

Speaker: Zehua Chen (TU/e, Computational Materials Physics Group)
Time: Oct. 29, 2020, 10:00–11:00
Location: Online (MS Teams)

Abstract | Under illumination, mixed halide perovskites that are thermodynamically stable in the dark can demix due to a free energy lowering of photocarriers that funnel to a nucleated phase with different halide composition and lower band gap than the parent phase. This is problematic for applying mixed halide perovskites in solar cells. I will present in this seminar a unified thermodynamic theory for this light-induced phase separation and apply it to five mixed iodine-bromine perovskites. The spinodals separating metastable and unstable regions in the composition-temperature phase diagrams shift upward in temperature under illumination, while new light-induced binodals separating stable and metastable regions appear that signal nucleation of a low-band gap iodine-rich phase. The threshold photocarrier density for phase separation is mainly governed by the band gap difference of the parent and iodine-rich phase. Partial replacement of organic cations by cesium reduces this difference and therefore has a stabilizing effect.

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 would like to attend, just This email address is being protected from spambots. You need JavaScript enabled to view it. so as to receive the MS Teams meeting link.

Title: Study and Design of Multifunctional Nanostructured Materials and complex molecules for Energy Applications

Speaker: Sofía Calero (TU/e, MSM)
Time: Oct. 8, 2020, 10:00–11:00
Location: Online (MS Teams)

On Sept. 1, we launched the Materials Simulation and Modelling Group (MSM) in the Department of Applied Physics. This group provides conceptual knowledge with the goal of achieving reductions in energy consumption and paving the way to develop a long-term research strategy to design and ‘invent’ materials. The group's research has three main branches: (1) Density Functional Theory based multiscale computer simulations with main focus on perovskite solar cells, (2) electronic structure 2D materials and (3) molecular simulations of porous materials and complex molecules. This presentation will focus on the latter branch, discussing the state of the art, current work, and what we envision in the short and long term. In particular, I will discuss force field development and high-performance methods for automatically calculating surface properties, as well as innovative approaches to assessing material stability and for identifying and designing high-performance multi-functional nanostructured materials.

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 would like to attend, just This email address is being protected from spambots. You need JavaScript enabled to view it. so as to receive the MS Teams meeting link.