Photolytically and environmentally stable multilayer structure for high efficiency electromagnetic energy conversion and sustained secondary emission

A method of fabricating a multilayer structure for authentication, said method comprising:

• forming an energy conversion layer comprising a polymer and a first photoluminescent material with a first absorption spectrum that at least partially overlaps with a primary electromagnetic radiation;
• overlaying at least one stability enhancement layer over at least one side of said energy conversion layer that increases the photolytic and thermal stability of said multilayer structure;
• and
• applying at least one blocking layer into or onto at least a portion of said energy conversion layer to prevent at least a portion of said energy conversion layer from converting the primary electromagnetic radiation to a longer output wavelength.

A method of identifying an object for authentication, said method comprising:

• applying a multilayer structure onto or into at least a portion of the object, said multilayer structure comprising:
• (i) an energy conversion layer that converts the energy of a primary electromagnetic radiation to a longer output wavelength, and
• (ii) at least one stability enhancement layer that increases the photolytic and thermal stability of said multilayer structure, and
• (iii) at least one blocking layer that prevents at least a portion of said energy conversion layer from converting energy of the primary electromagnetic radiation to the longer output wavelength, and
• wherein said multilayer structure is exposed to the primary electromagnetic radiation and the longer output wavelength is detected.