Phys.org July 9, 2024 Colloidal semiconductor nanocrystals based on CdSe have been precisely optimized for photonic applications in the visible spectrum. A team of researchers in the US (University of Illinois Urbana-Champaign, Carle Illinois College of Medicine, Urbana) developed homogeneous nanocrystals with tunable bandgaps in the infrared spectrum based on HgSe and HgxCd1−xSe alloys derived from CdSe precursors. They found that Ag+ catalyses cation interdiffusion reduced the CdSe–HgSe alloying temperature from 250 °C to 80 °C. Together with ligands that modulated surface cation exchange rates, interdiffusion-enhanced Hg2+ exchange of diverse CdSe nanocrystals proceeded homogeneously and completely. The products retained the size, shape […]
Category Archives: Nanocrystal
New nanocrystals put a tiny twist on useful materials
Phys.org January 12, 2022 Conductive MOFs possess rich compositions with complex architectures, but remain unexplored as nanocrystals, hindering their incorporation into scalable devices. MOFs form via a series of chemical reactions that join metal ions with linker molecules. Researchers at the University of Oregon made iron triazolate nanoparticles by adding a third ingredient, molecules that mimic the linkers, but that can only bind to something on one end. They act like dead-ends for the growing MOF, ensuring it stays small. They behaved differently at different sizes and temperatures. They could tune the materials to behave a certain way, by adjusting […]
Nanocrystal ‘factory’ could revolutionize quantum dot manufacturing
Phys.org March 15, 2019 Researchers at North Carolina State University have developed a microfluidic system (called NC Factory) which starts with cesium lead bromide perovskite quantum dots and introduced various halide salts to precisely tune their fluorescence color across the entire spectrum of visible light. Anions in these salts replace the bromine atoms in the green-emitting dots with either iodine atoms (to move toward the red end of the spectrum) or chlorine atoms (to move toward blue). Coupled with continuous process monitoring, the system can precisely control both chemical composition and processing parameters. It can be used to continuously manufacture […]