Multiscale Materials Modelling and Virtual Design

Welcome to the website of Prof. Wolfgang Wenzel's Research Group focused on the "Multiscale Materials Modelling and Virtual Design," one of the topics researched in Functional Molecules at the Institute of Nanotechnology (INT) at the Karlsruhe Institute of Technology.




Our Group

W. Wenzel
Prof. Dr. Wolfgang Wenzel
Research Unit Chair

+49 721 608-26386wolfgang wenzel does-not-exist.kit edu

Karlsruhe Institute of Technology (KIT)
Institute of Nanotechnology
Hermann-von-Helmholtz-Platz 1
76344 Eggenstein-Leopoldshafen, Germany


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Fluorescent Nanozeolite Receptors for the Highly Selective and Sensitive Detection of Neurotransmitters in Water and Biofluids

A completely new and modular receptor design strategy based on microporous hybrid materials is presented yielding zeolite-based artificial receptors (ZARs) which reversibly bind the neurotransmitters serotonin and dopamine with unprecedented affinity and selectivity even in saline biofluids. ZARs are thermally and chemically robust, can be readily prepared at gram scales and their applicability for the label-free monitoring of important enzymatic reactions, for (two-photon) fluorescence imaging, and for high-throughput diagnostics in biofluids is demonstrated.

Adv. Mat., DOI: 10.1002/adma.202104614
interplay of structural dynamics
Interplay of structural dynamics and electronic effects in an engineered assembly of pentacene in a metal–organic framework

In aggregated organic semiconductor (OSC), charge carrier mobility is determined by inter-chromophoric electronic and vibrational coupling, which depend on structural properties, including the density of defects. A new type of crystalline assembly strategy has been employed to engineer the arrangement of the OSC pentacene in a structure not realized as crystals to date. Using multiscale approach, we have proven the intrinsic rotational motion of the (rigid) pentacene strongly suppresses charge delocalization, suggesting the charge transport mechanism in this metal–organic framework (MOF), at the borderline between the localized hopping and delocalized charge transport. This opens new startegies towards enhancement of semiconducting properties of MOFs.

Chem. Sci., DOI: 10.1039/D0SC07073D
Method for accurate experimental determination of singlet and triplet exciton diffusion between thermally activated delayed fluorescence molecules

Understanding triplet exciton diffusion between organic thermally activated delayed fluorescence (TADF) molecules is a challenge due to the unique cycling between singlet and triplet states in these molecules. Singlet and triplet diffusion lengths can be accurately determined from experimental data. Theory confirms that the lack of overlap between the shielded lowest unoccupied molecular orbitals hinders triplet motion between TADF chromophores in such molecular architectures.

Chem. Sci., DOI: 10.1039/D0SC05190J
Toward Design of Novel Materials for Organic Electronics

Organic semiconductors are widely used in prominent applications such as organic light‐emitting diode displays and organic solar cells. The state of the art of predictive simulation methods is discussed, including machine learning, to complement experimental research in the identification of novel materials in the vast available chemical space, and their potential is illustrated with a few prominent recent applications.

Adv. Mat., DOI: 10.1002/adma.201808256
Inside front cover picture
Nanocrystalline graphene at high temperatures: insight into nanoscale processes

Nanocrystalline graphene shows significantly different high-temperature behavior compared to pristine graphene. In this work we analyze the dynamics of graphene formation during in situ heating experiments. Therefore, we combine high-throughput transmission electron microscopy and computational modeling to get an insight into fundamental processes. We observe that the reactive nature of unsaturated edges and defects in nanocrystalline graphene enables various temperature-driven rearrangement mechanisms.

Nanoscale Adv., DOI: 10.1039/C9NA90036E
GRK 2450
GRK: Tailored Scale-Bridging Approaches to Computational Nanoscience

The last decades brought a massive development of simulation methods for materials science, chemistry and soft matter applications, now being efficient and accurate for the targeted application area. In this RTG we will systematically investigate problems, which are not addressable by standard tools from the quantum chemistry toolbox.  The research is organized into seven projects, where five projects address scientific challenges like friction, materials aging, material design and biological function, which so far cannot be approached by single computational methods or standard multiscale approaches. The challenges are met, (i) by building teams which cover all knowledge and methods required to address scale-bridging problems, (ii) by a research program, which aims at a novel holistic, problem-driven approach to combine existing methods on the individual scales to recursive scale-bridging workflows and (iii) by training doctoral researchers, who are enabled to apply scale-bridging concepts and technical skills needed for such a problem-driven approach.

GRK 2450
Excellence cluster 3DMM2O

We are proud to be part of the the new excellence cluster 3D Matter Made to Order (3DMM2O)!

Rational In Silico Design of an Organic Semiconductor with Improved Electron Mobility

The viability of a multiscale simulation approach to rationally design organic semiconductors with improved electron mobility is demonstrated. Novel materials with tailored electronic properties are designed for which an improvement of the electron mobility by three orders of magnitude is predicted and experimentally confirmed.

Adv. Mat, DOI: 10.1002/adma.201703505
Backcover of advanced materials
Switching the Proton Conduction in Nanoporous, Crystalline Materials by Light

Proton‐conducting molecules in the pores of metal–organic frameworks change their conductivity upon photoswitching the host framework. In this work, irradiation with light (green) causes trans–cis isomerization of the azobenzene components of the framework, switching the molecular interaction and the conductivity of the triazole guest molecules (center). The sample is mounted on interdigitated gold electrodes, which are used for measuring the conductivity.

Adv. Mat., DOI: 10.1002/adma.201706551
Charge Transport in Organic LED

This video illustrates the principle of OLED devices. Electrons and holes are injected at the electrodes, drift through the device and emit light when they recombine. The charge carrier movement in a real device can be simulated using the kinetic Monte-Carlo method, which has been implemented in our group.

Video posted on YouTube