Metal-halide-perovskites revolutionized the field of thin-film semiconductor technology, due to their favorable optoelectronic properties and facile solution processing. Further improvements of perovskite thin-film devices require structural coherence on the atomic scale. Such perfection is achieved by epitaxial growth, a method that is based on the use of high-end deposition chambers. Here epitaxial growth is enabled via a ≈1000 times cheaper device, a single nozzle inkjet printer. By printing, single-crystal micro-and nanostructure arrays and crystalline coherent thin films are obtained on selected substrates. The hetero-epitaxial structures of methylammonium PbBr 3 grown on lattice matching substrates exhibit similar luminescence as bulk single crystals, but the crystals phase transitions are shifted to lower temperatures, indicating a structural stabilization due to interfacial lattice anchoring by the substrates. Thus, the inkjet-printing of metal-halide perovskites provides improved material characteristics in a highly economical way, as a future cheap competitor to the high-end semiconductor growth technologies.

Chalcogenide perovskites are a promising and novel class of materials in the fields of solar cells and related subjects. However, the synthesis of thin films of these materials still is troublesome. This work attempts to utilize a phase in the Ba‐S phase system with low melting point, namely, BaS3, for the thin‐film synthesis of BaZrS3. The successful synthesis of BaS3 thin films is presented and confirmed by field‐emission scanning electron microscopy (FESEM), X‐ray diffraction (XRD), and Raman analysis. The microstructure of the synthesized BaS3 thin films shows defects and cracks and therefore needs further optimization for the use for BaZrS3 thin‐film synthesis. However, the successful synthesis of BaS3 thin films is potentially a great step toward a facile BaZrS3 thin‐film synthesis.

Hydrogel optimisation for biofabrication considering shape stability/mechanical properties and cell response is challenging. One approach to tackle this issue is to combine different additive manufacturing techniques, e.g., hot-melt extruded thermoplastics together with bioplotted cell loaded hydrogels in a sequential plotting process. This method enables the fabrication of 3D constructs mechanically supported by the thermoplastic structure and biologically functionalised by the hydrogel phase. In this study, polycaprolactone (PCL) and polyethylene glycol (PEG) blend (PCL-PEG) together with alginate dialdehyde gelatine hydrogel (ADA-GEL) loaded with stromal cell line (ST2) were investigated. PCL-PEG blends were evaluated concerning plotting properties to fabricate 3D scaffolds, namely miscibility, wetting behaviour and in terms of cell response. Scaffolds were characterised considering pore size, porosity, strut width, degradation behaviour and mechanical stability. Blends showed improved hydrophilicity and cell response with PEG blending increasing the degradation and decreasing the mechanical properties of the scaffolds. Hybrid constructs with PCL-PEG blend and ADA-GEL were fabricated. Cell viability, distribution, morphology and interaction of cells with the support structure were analysed. Increased degradation of the thermoplastic support structure and proliferation of the cells not only in the hydrogel, but also on the thermoplastic phase, indicates the potential of this novel material combination for biofabricating 3D tissue engineering scaffolds.

No abstract

No abstract