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Molecular machines offer many opportunities for the development of responsive materials and introduce autonomous motion in molecular systems. While basic molecular switches and motors carry out one type of motion upon being exposed to an external stimulus, the development of molecular systems capable of performing coupled motions is essential for the development of more advanced molecular machinery. Overcrowded alkene-based rotary molecular motors are an ideal basis for the design of such systems as they undergo a controlled rotation initiated by light allowing for excellent spatio-temporal precision. Here, we present an example of a Pd complex of a second-generation rotary motor whose Pd center undergoes a coupled oscillatory motion relative to the motor core upon rotation of the motor. We have studied this phenomenon by UV-vis, NMR, and density functional theory calculations to support our conclusions. With this demonstration of a coupled rotation-oscillation motion powered by a light-driven molecular motor, we provide a solid basis for the development of more advanced molecular machines integrating different types of motion in their operation.

Metal halide perovskites (MHPs) have shown an incredible rise in efficiency, reaching as high as 25.7%, which now competes with traditional photovoltaic technologies. Herein, we excluded CsX and RbX, the most commonly used cations to stabilize FAPbI3, from the bulk of perovskite thin films and applied them on the surface, as passivation agents. Extensive device optimization led to a power conversion efficiency (PCE) of 24.1% with a high fill factor (FF) of 82.2% upon passivation with CsI. We investigated in-depth the effect of CsI passivation on structural and optoelectronic properties using X-ray diffraction (XRD), angle resolved X-ray photoelectron spectroscopy (ARXPS), Kelvin Probe Force (KPFM) microscopy, time-resolved photoluminescence (TRPL), photoluminescence quantum yield (PLQY) and electroabsorption spectroscopy (TREAS). Furthermore, passivated devices exhibit enhanced operational stability, with optimized passivation with CsI leading to a retention of ~90% of initial PCE under 1 Sun illumination with maximum power point tracking for 600 h., Comment: 27 pages, 19 figures

Additional file 1.

Galectins represent β-galactoside-binding proteins with numerous functions. Due to their role in tumor progression, human galectins-1, -3 and -7 (Gal-1, -3 and -7) are potential targets for cancer therapy. As plant derived glycans might act as galectin inhibitors, we prepared galactans by partial degradation of plant arabinogalactan-proteins. Besides commercially purchased galectins, we produced Gal-1 and -7 in a cell free system and tested binding capacities of the galectins to the galactans by biolayer-interferometry. Results for commercial and cell-free expressed galectins were comparable confirming functionality of the cell-free produced galectins. Our results revealed that galactans from Echinacea purpurea bind to Gal-1 and -7 with KD values of 1–2 µM and to Gal-3 slightly stronger with KD values between 0.36 and 0.70 µM depending on the sensor type. Galactans from the seagrass Zostera marina with higher branching of the galactan and higher content of uronic acids showed stronger binding to Gal-3 (0.08–0.28 µM) compared to galactan from Echinacea. The results contribute to knowledge on interactions between plant polysaccharides and galectins. Arabinogalactan-proteins have been identified as a new source for production of galactans with possible capability to act as galectin inhibitors.

A set of supplementary data filesAccompanying publication: Arabinogalactan-proteins of Zostera marina L. contain unique glycan structures and provide insight into adaption processes to saline environments, (MBE 2020 https://doi.org/10.1093/molbev/msaa096)Supplementary Data S1. Classical HRGPs from MAAB (signalP filtered) Unaligned sequences of HRGPs as fasta file Supplementary Data S2. Chimeras by clan (signalP filtered) Unaligned sequences of chimeric AGPs as fasta files, organised by clan of the globular domain Supplementary Data S3. Enzyme trimmed alignments and trees Multiple sequence alignments of enzymes as fasta files and phylogenetic trees as newick files

This invention relates to an optoelectronic or photovoltaic device comprising a perovskite or metal halide perovskite film treated by one or more compounds of formula (I): ((R1-NH(R2)-R3)+)nW (I), wherein n is an integer selected from 1, 2, or 3; R1, R2, R3 are independently selected from a hydrocarbyl group containing 1-40 carbon atoms said hydrocarbyl group, if said hydrocarbyl group comprises 3 or more carbons, may be linear or branched; and W is an anion.

Metal halide perovskites (MHPs) have shown an incredible increase in efficiency, reaching as high as 25.7%, which now competes with traditional photovoltaic technologies. Herein, we excluded CsX and RbX (X = I–, Br–, Cl–), the most commonly used cations to stabilize α-FAPbI3, from the bulk of perovskite thin films and applied them on the surface as passivation agents. Extensive device optimization led to a power conversion efficiency (PCE) of 24.1% with a high fill factor (FF) of 82.2% upon passivation with CsI. We investigated in depth the effect of CsI passivation on structural and optoelectronic properties using X-ray diffraction (XRD), angle-resolved X-ray photoelectron spectroscopy (ARXPS), Kelvin probe force microscopy (KPFM), time-resolved photoluminescence (TRPL), photoluminescence quantum yield (PLQY), and electroabsorption spectroscopy (TREAS). Furthermore, passivated devices exhibit enhanced operational stability, with optimized passivation with CsI leading to a retention of ∼90% of the initial PCE under 1 sun illumination with maximum power point tracking for 600 h.

Over the past three decades, dye-sensitized solar cells (i. e. Gratzel cells) have evolved from a pioneering concept of molecular photovoltaics to large-scale industrial deployment. In this review article, we provide a historical overview of the developments with a focus on the scientific advancements that have set the stage for this technology to emerge and thrive. This involves insights into the (photo)electrochemistry of the underlying processes, molecular engineering of dyes, redox shuttles, and hole-transporting materials, as well as their implementation into solar cells. We further outline applications and future perspectives, involving the long-lasting objective to develop efficient solid-state alternatives to conventional dye-sensitized solar cells.

Organic materials can tune the optical properties in layered (2D) hybrid perovskites, although their impact on photophysics is often overlooked. Here, we use transient absorption spectroscopy to probe the Dion−Jacobson (DJ) and Ruddlesden−Popper (RP) 2D perovskite phases. We show the formation of charge transfer excitons in DJ phases, resulting in a photoinduced Stark effect which is shown to be dependent on the spacer size. By using electroabsorption spectroscopy, we quantify the strength of the photoinduced electric field, while temperature-dependent measurements demonstrate new features in the transient spectra of RP phases at low temperatures resulting from the quantum-confined Stark effect. This study reveals the impact of spacer size and perovskite phase configuration on charge transfer excitons in 2D perovskites of interest to their advanced material design.

Heteroaromatic units are commonly used as pi-spacers for sensitizers in dye-sensitized solar cells (DSSCs). Here, we investigated the influence of the pi-spacer on the photophysical properties, electrochemical properties and photovoltaic performance of carbazol-phenyl functionalized phenothiazine donor based organic dyes, i.e., CPPC-No (without a pi-spacer), CPPC-Th (thiophene as the pi-spacer), CPPC-Fu (furane as the pi-spacer), CPPC-Ph (phenyl as the pi-spacer) and CPPC-Py (pyridine as the pi-spacer). The solar to electric power conversion efficiency (PCE) achieved with these dyes strongly depends on the type of pi-spacer, increasing in the order of CPPC-Ph < No < Py < Th < Fu. The width of the absorption band and the photocurrent density increased with the electron richness of the pi-spacer. Theoretical calculations indicated that the planar molecular configuration of CPPC-Fu promotes the intramolecular charge transfer process. As a result, the CPPC-Fu based device showed a PCE of 7.4% under one sunlight illumination. The dyes using thiophene and pyridine as pi-spacers showed slightly lower performance, however, still significantly higher than the PCE achieved with the control compound lacking a pi-spacer. By contrast, introducing a phenyl group as the pi-spacer led to a decrease in device efficiency. These results give deeper insight into the effect of different pi-spacers on DSSC performance, showing the importance of molecular engineering in developing high efficiency organic dyes.

Layered hybrid perovskites are based on organic spacers separating hybrid perovskite slabs. We employ arene and perfluoroarene moieties based on 1,4-phenylenedimethylammonium (PDMA) and its perfluorinated analogue (F-PDMA) in the assembly of hybrid layered Dion-Jacobson perovskite phases. The resulting materials are investigated by X-ray diffraction, UV-vis absorption, photoluminescence, and solid-state NMR spectroscopy to demonstrate the formation of layered perovskite phases. Moreover, their behaviour was probed in humid environments to reveal nanoscale segregation of layered perovskite species based on PDMA and F-PDMA components, along with enhanced stabilities of perfluoroarene systems, which is relevant to their application.