Tuning the Shades of Red Emission in InP/ZnSe/ZnS Nanocrystals with Narrow Full Width for Fabrication of Light-Emitting Diodes.

While Cd-based luminescent nanocrystals (NCs) are the most mature NCs for fabricating efficient red light-emitting diodes (LEDs), their toxicity related limitation is inevitable, making it necessary to find a promising alternative. From this point of view, multishell-coated, red-emissive InP-based NCs are excellent luminescent nanomaterials for use as an emissive layer in electroluminescent (EL) devices. However, due to the presence of oxidation states, they suffer from a wide emission spectrum, which limits their performance. This study uses tris(dimethylamino)phosphine (3DMA-P) as a low-cost aminophosphine precursor and a double HF treatment to suggest an upscaled, cost-effective, and one-pot hot-injection synthesis of purely red-emissive InP-based NCs. The InP core structures were coated with thick layers of ZnSe and ZnS shells to prevent charge delocalization and to create a narrow size distribution. The purified NCs showed an intense emission signal as narrow as 43 nm across the entire red wavelength range (626-670 nm) with an emission quantum efficiency of 74% at 632 nm. The purified samples also showed an emission quantum efficiency of 60% for far-red wavelengths of 670 nm with a narrow full width of 50 nm. The samples showed a relatively long average emission lifetime of 50-70 ns with a biexponential decay profile. To demonstrate the practical ability of the prepared NCs in optoelectronics, we fabricated a red-emissive InP-based LEDs. The best-performing device showed an external quantum efficiency (EQE) of 1.16%, a luminance of 1039 cd m-2, and a current efficiency of 0.88 cd A-1.

Self-Healing of Biocompatible Superhydrophobic Coatings: The Interplay of the Size and Loading of Particles.

The broad application potential of superhydrophobic coatings is limited by the usage of environment-threatening materials and poor durability. The nature-inspired design and fabrication of self-healing coatings is a promising approach for addressing these issues. In this study, we report a fluorine-free and biocompatible superhydrophobic coating that can be thermally healed after abrasion. The coating is composed of silica nanoparticles and carnauba wax, and the self-healing is based on surface enrichment of wax in analogy to the wax secretion in plant leaves. The coating not only exhibits fast self-healing, just in 1 min under moderate heating, but also displays increased water repellency and thermal stability after healing. The rapid self-healing ability of the coating is attributed to the relatively low melting point of carnauba wax and its migration to the surface of the hydrophilic silica nanoparticles. The dependence of self-healing on the size and loading of particles provides insights into the process. Furthermore, the coating exhibits high levels of biocompatibility where the viability of fibroblast L929 cells was ∼90%. The presented approach and insights provide valuable guidelines in the design and fabrication of self-healing superhydrophobic coatings.

A facile synthesis of Ag2MnSnS4 nanorods through colloidal method.

The production methods of semiconductor nanomaterials with new shapes and different compositions form the basis for the creation of high-performance structures in numerous applications. Kesterite structured materials are among these inorganic semiconductors and are suggested to be promising energy materials for the future. In this study, quaternary Ag2MnSnS4 nanocrystalline rods have been successfully synthesized for the first time by the colloidal hot-injection synthesis route and well-organized rod-like nanocrystals (NCs) with lengths ranging from 200 to 350 nm and widths from 10 to 30 nm were obtained. For this structure, the Ag2MnSnS4 exhibits a semiconductor property with a band-gap of approximately 1.3 eV. The optical properties and band-gap values were determined by UV-Vis absorption spectrum and using Tauc Equation. It has been observed that the Ag2MnSnS4 structure acquired by the proposed colloidal synthesis method can be an alternative to the commonly used materials based on Cd and Pb.