National Research Council of Canada

Multi-magnetics Inc.

Kui Yu

Frank S Prato

Alex W Thomas

Robert Z Stodilka

John A Ripmeester

Jianying Ouyang

Terry R Thompson

Jeff Carson

Diana Wilkinson

Chunsheng Li

A method of synthesizing colloidal semiconductor nanocrystals involves contacting a source of at least one semi-conductor cation element (Group 11-14, more preferably Group 12-14, more preferably 12 or 14, more preferably Cd, Zn, Hg or Pb, most preferably Cd) with a source of at least one Group 15, or 16 element in the presence of a ligand forming compound containing a carboxylic acid moiety in a reaction medium comprising a solvent that is substantially noncoordinating with respect to the at least one cation, the ligand forming compound and the source of at least one cation element having a molar ratio of 1:1 or less. The cation element source is preferably bonded to two low carbon acids. Some of the low carbon acids are substituted with the ligand forming compound to produce a cation precursor that is more soluble in the noncoordinating solvent. The method produces novel ensembles of colloidal semiconductor nanocrystals that have narrow linewidth absorption and bandgap photoluminescence spectra indicating that the colloidal semiconductor nanocrystals are of substantially a single size. The single size families are produced for CdSe, CdTe, CdS, CdSeTe, and CdP.

Colloidal nanocrystal ensembles with narrow linewidth band gap photoluminescence and methods of synthesizing colloidal semiconductor nanocrystals

The invention is the novel use of Quantum Dots (QDs) for radiation dosimetry and includes novel dosimetry devices, systems and methods. The devices, systems and methods have use in a variety of dosimetry applications such as personal, environmental and research. The system for detecting doses of ionizing radiation comprises; a matrix comprising a photoluminescent semiconductor nanocrystals; an illumination interface for exposing the matrix to non-ionizing radiation; a response characterization interface for measuring photoluminescence, scatter or the optical density of the matrix and identifying differences in the photoluminescence, scatter or optical density caused by exposure to ionizing radiation; and a readout interface to quantify the photoluminescence or optical density differences as doses of radiation.

System and methods using quantum dots as general dosimeters

A method of making nanocrystals involves adding a chalocogen source to a hot solution of a metal-containing non-organometallic compound, such as CdO, in a first ligand solvent, such as TOP, and preferably subsequently cooling the resulting mixture to a lower temperature to grow the nanocrystals at said lower temperature. The method can involve either one ligand or two-ligand systems.

Method of synthesizing colloidal nanocrystals

Growing community of inventors

Kanata, Canada

Kui Yu