The new effective chemical synthesis of epitaxial VO ₂ films with record electrical and optical switch properties is presented.

To develop the recently proposed approach toward host selection for lanthanide-based emitters, four phosphine oxides PO = PO1–PO4 were investigated which are able to both increase the electron mobility and to sensitize terbium luminescence. New highly soluble and brightly luminescent terbium complexes TbCl₃(PO)·H₂O and Tb(pobz)₃(PO)·(CH₃)₂CO (pobz⁻ = phenoxybenzoate) with a quantum yield of up to 100% were synthesized and thoroughly characterized. To study the electroluminescence properties of these materials, a series of solution-processed OLED devices were fabricated and their heterostructures were selected based on the HOMO and LUMO energies of PO1–PO4, which were carefully assessed by the combination of DFT and TDDFT methods. Thus, the effectiveness of the proposed approach was proved, and the influence of the anionic ligand was shown. The maximum OLED luminance reached 75 Cd m⁻², which is a high value for solution-processed OLEDs based on terbium complexes.

The growing family of two-dimensional crystals has been recognized as a promising platform for investigation of rich low-dimension physics and production of a variety of devices. Of particular interest are recently reported atomic sheets of non-van der Waals materials, which reshape our understanding of chemical bonds and enable heterostructures with novel functionality. Here, we study the structural and optical properties of ultrathin non-van der Waals InGaS₃ sheets produced by standard mechanical cleavage. Our ab initio calculations reveal weak out-of-plane covalent bonds, responsible for the layered structure of the material. The energy required for isolation of a single layer is as low as ~50 meVÅ^–2, which is comparable with the conventional van der Waals material’s monolayer isolation energies of 20–60 meVÅ^–2. A comprehensive study of the structural, vibrational, and optical properties of the material reveals its wide bandgap (2.73 eV), high refractive index (>2.5) and negligible losses in the visible and infrared spectral ranges. These properties make it a perfect candidate for visible-range all-dielectric nanophotonics.