Nanowerk February 21, 2024 Research has predominantly focused on inorganic cation perovskite-based colloidal quantum dots (PQDs) even though organic cation PQDs have more favorable bandgaps. Researchers in South Korea developed solar cells using narrow bandgap organic cation based PQDs and demonstrated substantially higher efficiency compared with their inorganic counterparts. They employed an alkyl ammonium iodide-based ligand exchange strategy, which proved to be substantially more efficient in replacing the long-chain oleyl ligands than conventional methyl acetate-based ligand exchange while stabilizing the α phase of organic PQDs in ambient conditions. They showed a solar cell with the organic cation PQDs with high […]
Tag Archives: quantum dot
Mini electricity generator made from quantum dots
Phys.org January 18, 2022 The major challenges toward the exploitation of graphene nanoribbons (GNRs) in electronic applications include reliable contacting, and the preservation of their physical properties upon device integration. An international team of researchers (Switzerland, UK, Germany) described the quantum dot behavior of atomically precise GNRs integrated in a device geometry. The devices consist of a film of aligned five-atom-wide GNRs (5-AGNRs) transferred onto graphene electrodes with a sub 5 nm nanogap. They demonstrated that the narrow-bandgap 5-AGNRs exhibit metal-like behavior at room temperature and single-electron transistor behavior for temperatures below 150 K. They obtained addition energies in the […]
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 […]
A new kind of quantum bits in two dimensions
Nanowerk March 19, 2018 An international team of researchers (Germany, Austria, Hungary, UK) succeeded in developing a new type of quantum dots by combining graphene and hexagonal boron nitride, also a single layer of material quite like graphene except that it is insulating. The two layers cannot perfectly match when put one on top of the other resulting in an extremely regular wave-like spatial oscillation of the graphene layer out of the perfect plane. The potential landscape created by the regular superstructure allows for accurately placing the quantum dot, or even moving it continuously and thus smoothly changing its properties… […]