Typically, the nanodots and nanorods consist of spherical rod-like nanometer-size cores made by CdSe, CdS, CdTe, ZnSe and their alloys. For the near- and mid-infrared spectral range the core can be made from CdTe, HgSe, PbS, PbSe. The average diameter of the core lies within the 2 - 10 nm. Epitaxial shell of wide-gap ZnS, ZnSe, CdS semiconductors ca. 1-2 nm in thickness is grown atop the core. The presence of shell ensures high luminescent quantum yield of nanodots and nanorods and preserves the core from the photodegradation, especially in aqueous solutions. The highly luminescent core-shell nanodots and nanorods originally are synthesized as hydrophobic compounds. They are easily soluble in organic solvents, like toluene, chloroform, tetrahydrofuran, pyridine, hexane etc. and may be processed from their solutions to thin composite films, organized micro-and nanostructures, bulk polymeric and inorganic sol-gel materials. For the biological etc. applications the nanodots and nanodots may be prepared as stable aqueous colloidal solutions by special post-treatment of the original hydrophobic compounds.

Highly luminescent inorganic semiconductor nanodots are synthesized typically by the high temperature organometallic synthesis. This procedure gives the nanoparticles having on their surface the stabilizing shell of hydrophobic organic molecules (mostly trioctylphosphine oxide). The presence of organic molecules on the surface makes them soluble only in certain organic solvents, such as toluene, chloroform, hexane, tetrahydrofuran, pyridine etc. The special chemical post treatment of nanodots and nanorods must be done in order to make them soluble in water or the polar organic solvents, like alcohols (see, below in the chapters Water-soluble core-shell nanodots and Water-soluble core-shell nanorods). The original hydrophobic core-shell nanoparticles may be utilized in the various applications where the materials and structures containing nanodots and nanorods are prepared using the nonpolar organic solvents. Such applications may include the preparation of thin polymeric films via spin and dip casting, bulk polymeric parts via block polymerization, polymeric latexes etc. Also, hydrophobic nanodots and nanorods may be used for further water solubilization for the biological, biomedical and nanotechnological applications.