The electrochemical Performance of a supercapacitor strongly depends on the pore structure of the electrode material. We have investigated the influence of the mesopore structure on the capacitance for elevated charging and discharging rates.
New paper published in Carbon: From real space pore structures, derived from small-angle X-ray scattering, a pore size distribution of activated carbon materials was calculated and compared to results obtained from gas sorption analysis. Additionally, it was shown that the often used slit pore assumption narrows the actual pore size distribution.
Ultrathin hexagonal boron nitride is an ideal substrate for the fabrication of high quality organic crystalline thin films and devices with maximized performance.
The use of hexagonal boron nitride (hBN) as ultra-smooth, weakly interacting van der Waals substrate for organic thin film growth and self-organization is an active area of research. hBN effectively decouples the adsorbed species from the support making intrinsic material’s properties visible which would otherwise be masked by the strong surface-adsorbate interaction. Thus, new insights in fundamental aspects of intermolecular interaction, self-assembly, electronic structure or chemical reactions are possible.
In cooperation with scientists of the National Academy of Sciences of the Ukraine and Slovakia we have demonstrated that differently doped atomic force microscopy probes can be used a submicrometer electrodes to probe and discriminate different semiconductor domains in CdS/Kesterite bulk heterojunction solar cells.
Scientists of the Material Center Leoben, the Department of Material Physics of the Montanuniversitaet Leoben, and Gerhard Popovski of the Institute of Physics have shown that different copper surfaces will influence the growth of copper oxide nanowires. Small copper grains and high surface roughness promote the growth of these important structures, which are used for example in solar cells or sensors.
The Shape of Nanocrystals Influences their Optical Performance: Revealed in an open access article in Frontiers of Chemistry
Scientists from the Institute of Physics together with colleagues of the ETH Zürich as well as the ESRF in Grenoble showed recently that the crystal structure of core/shell CdSe/CdS nanocrystals (3.5 -14 nm) influences the particle shape. The particle shape again directly influences the photoluminescence (PL) quantum yield: The “larger”, strongly faceted nanocrystals with dimensions of up to 14 nm and aspect ratios of around 1.7 show the lowest PL output. These results were only possible with combined scattering (anomalous SAXS) and diffraction (WAXS) experiments at the synchrotron ESRF.
New paper published in Nature Communications on parameters determining charge storage mechanisms in nanoporous supercapacitors
To improve the performance of supercapacitors, a mechanistic understanding of ion electrosorption is required. In this work we identify parameters like salt concentration, charging velocity or cell design, controlling mechanisms of ion charge storage. Moreover, we show that charging initially leads to a non-equilibrium ion configuration even at extremely low cycling speed, followed by an increase of the total ion concentration, i.e. a charge-neutral equilibration.
New paper published in Nanoscale reveals peculiar nano-mechanics of the van der Waals interface between organic nanostructures and 2D materials
Self-assembled and self-alligned organic nanostructures are very interesting building blocks for the future nanoelectromechanics, especially considering an increasing demand to improve, miniaturize, and integrate various sensors into low-power wearable (flexible) applications. Unique nanomechanics that exists on these scales might appear as counter-intuitive in a macroscopic world, and therefore understanding of the underlying mechanisms is a key step in advancement of these technologies.
The impact of the paper on "3D colloidal supercrystals" is further illustrated by the fact that is was selected as Inside Front Cover in Volume 30, Issue 32, August 9, 2018 of Advanced Materials
In this study three Austrian Universities the TU Graz, the Univ. Wien led by the MU Leoben worked together to reveal the supercrystal structure of free standing 3D colloidal supercrystals by combining in-situ synchrotron SAXS experiments at ELETTRA with simulations.