nanoplate

Nanoplate refers to a nanoscale plate-like particle with thickness on the order of a few nanometers or less and lateral dimensions much larger, yielding a high aspect ratio. The term is commonly applied to two classes: semiconductor nanoplatelets and metallic nanoplatelets.

Semiconductor nanoplatelets are crystalline, quasi-two-dimensional nanocrystals in which thickness is controlled at the atomic or sub-nanometer scale, often one to several monolayers, while lateral sizes reach tens to hundreds of nanometers. This confinement along the thickness produces distinctive optical properties, including tunable emission and relatively narrow linewidths. Core/shell structures such as CdSe/CdS are widely studied, with emission color determined mainly by thickness and composition.

Metallic nanoplatelets, including gold and silver forms, are ultrathin crystalline plates typically a few nanometers thick and tens to hundreds of nanometers across. They exhibit plasmonic resonances that depend on thickness and lateral size, enabling strong, tunable light absorption and scattering.

Synthesis commonly relies on colloidal chemical methods. Semiconductor NPLs are made by hot-injection and controlled growth to set thickness, using ligands and precursors to steer crystallinity. Metallic NPLs are produced by seed-mediated growth or reduction in the presence of shape-directing agents, with thickness controlled by reaction parameters.

Applications span optoelectronics and catalysis. Semiconductor NPLs are explored for light-emitting diodes, lasers, and bio-imaging due to their color purity and processability. Metallic NPLs find use in plasmonic sensors, photothermal therapy, and nanophotonic devices. Challenges include synthesis reproducibility, stability, and scalability.