SPECTRAL CODING BY FLUORESCENT SEMICONDUCTOR NANOCRYSTALS FOR DOCUMENT IDENTIFICATION AND SECURITY APPLICATIONS

摘要

Methods of coding and retrieving information by using the unique emission properties of the semiconductor nanocrystals (quantum dots) for the identification of valuable documents, articles and objects are described. A carrier medium is prepared containing quantum dots selected to give the carrier medium defined fluorescent emission characteristics encoding predetermined information. The carrier medium is then applied to the object, preferably in the form of an ink.