Robust singlet fission in pentacene thin films with tuned charge transfer interactions

Singlet fission, the spin-allowed photophysical process converting an excited singlet state into two triplet states, has attracted significant attention for device applications. Research so far has focused mainly on the understanding of singlet fission in pure materials, yet blends offer the promise of a controlled tuning of intermolecular interactions, impacting singlet fission efficiencies. Here we report a study of singlet fission in mixtures of pentacene with weakly interacting spacer molecules. Comparison of experimentally determined stationary optical properties and theoretical calculations indicates a reduction of charge-transfer interactions between pentacene molecules with increasing spacer molecule fraction. Theory predicts that the reduced interactions slow down singlet fission in these blends, but surprisingly we find that singlet fission occurs on a timescale comparable to that in pure crystalline pentacene. We explain the observed robustness of singlet fission in such mixed films by a mechanism of exciton diffusion to hot spots with closer intermolecular spacings.

[A modular method for automated evaluation of gait analysis data]

A modular methodology for automated gait data evaluation: The aim of Instrumented Gait Analysis is to measure data such as joint kinematics or kinetics during gait in a quantitative way. The data evaluation for clinical purposes is often performed by experienced physicians (diagnosis of specific motion dysfunction, planning and validation of therapy). Due to subjective evaluation and complexity of the pathologies, there exists no objective, standardized data analysis method for these tasks. This article covers the development of a modular, computer-based methodology to quantify the degree of pathological gait in comparison to normal behavior, as well as to automatically search for interpretable gait abnormalities and to visualize the results. The outcomes are demonstrated with two different patient groups.