Publications by authors named "Fabian Eller"

Measuring absorption spectra of strongly absorbing solutions is usually only possible by diluting the solution. However, the absorption spectra can be heavily influenced by concentration-dependent interactions, so dilution leads to misleading results. To enable reliable absorption measurements of concentrated solutions, we introduce in this work thinning fluid film spectroscopy (TFFS), a simple and highly automatable method.

View Article and Find Full Text PDF

X-ray photon correlation spectroscopy (XPCS) is a versatile tool to measure dynamics on the nanometer to micrometer scale in bulk samples. XPCS has also been applied in grazing incidence (GI) geometry to examine the dynamics of surface layers. However, considering GI scattering experiments more universally, the GI geometry leads to a superposition of signals due to reflection and refraction effects, also known from the distorted-wave Born approximation (DWBA).

View Article and Find Full Text PDF

The properties of semiconducting polymers are strongly influenced by their aggregation behavior, that is, their aggregate fraction and backbone planarity. However, tuning these properties, particularly the backbone planarity, is challenging. This work introduces a novel solution treatment to precisely control the aggregation of semiconducting polymers, namely current-induced doping (CID).

View Article and Find Full Text PDF

The development of an environmentally friendly fabrication process for non-fullerene acceptor organic solar cells is an essential condition for their commercialization. However, devices fabricated by processing the active layer with green solvents still struggle to reach, in terms of efficiency, the same performance as those fabricated with halogenated solvents. The reason behind this is the non-optimal nanostructure of the active layer obtained with green solvents.

View Article and Find Full Text PDF

Polymeric thin films offer a wide range of exciting properties and applications, with several advantages compared to inorganic counterparts. The thermal conductivity of such thin films ranges typically between 0.1-1 W m-1 K-1.

View Article and Find Full Text PDF

A major advantage of organic solar cells (OSC) is the processability out of solution allowing for advanced printing methods toward large-scale production. Controlling the blend morphology of solution coated active layers is a key challenge to optimize their power conversion efficiency. We have derived a printing procedure from an industrial coating process that facilitates tuning the nanomorphology of a blend of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as model system for OSCs.

View Article and Find Full Text PDF