Temperature Activated Changes to Light Absorption and Emission Characteristics for Security Articles

摘要

Disclosed are security articles and methods and systems for authenticating security articles through the application if temperature related stimuli. Carefully synthesized nanostructures are formed to exhibit a large number of defect states within the bulk of the nanostructure. The large number of surface defects create a plurality of electron trap states below the conduction band of the composition and/or a plurality of hole states above the valance band such that excitations are induced by small changes in energy at or around kT. In this manner, a security article formed using the synthesized nanostructures produces measurable changes in spectral output based on small changes in temperature at or about room temperature. This allows the security article to be verified at high speeds with low power requirements for induced temperature change.

主权项

1. A security article, comprising:
a host material comprising a temperature sensitive security feature comprising a plurality of nanostructures having a high surface area to volume ratio exhibiting large numbers of excitation defects therein incorporated upon or within the host material, wherein the temperature sensitive security feature is capable of emitting a spectral emission that changes upon exposure to a change in temperature of the temperature sensitive security feature.