Nanokrystaller

Nanokrystaller are nanoscale crystalline particles that possess well-defined lattice structures and sizes typically between 1 and 100 nanometers. At these dimensions, many materials exhibit quantum confinement effects that alter electronic and optical properties relative to bulk materials. Nanocrystals can be composed of inorganic semiconductors, metals, metal oxides, or hybrid materials such as perovskites.

Common synthesis methods include colloidal synthesis in solution, often employing hot-injection to control nucleation and growth; gas-phase synthesis; hydrothermal or solvothermal routes. Size and shape control yield monodisperse populations and distinct crystal facets. Nanocrystals are often core-shell constructs to improve stability and quantum yield; surface ligands such as long-chain amines, carboxylates, phosphines, or thiols passivate surface states and dictate solubility.

Key properties include absorption and emission spectra that shift with particle size; photoluminescence quantum yield; charge transport properties. Characterization relies on transmission electron microscopy, X-ray diffraction to determine crystal structure, and spectroscopic methods to assess optical properties.

Applications span light-emitting diodes, display technologies, solar cells, biological imaging, and catalysis. Challenges include material toxicity for cadmium- and lead-containing nanocrystals, environmental and health considerations, stability under air and moisture, and issues related to scalable, reproducible manufacturing and regulatory oversight.