Improvements relating to the authentication of physical entities
AssigneeQuantum Base Limited
InventorsVladimir Falko, Robert Young
Life of this patent
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Abstract
An authentication device (20) comprises one or more flakes of a substantially two-dimensional material (14). The one or more flakes of the substantially two-dimensional material (14) have an operative area configured to emit, by non-resonant photoluminescence, electromagnetic radiation with a property that varies with position in the operative area.
Claims45
An authentication device comprising one or more flakes of a substantially two-dimensional material with an operative area configured to emit, by non-resonant photoluminescence, electromagnetic radiation with a property that varies with position in the operative area.
An authentication device as claimed in any preceding claim, wherein the emitted electromagnetic radiation has a wavelength that differs from a wavelength of incident electromagnetic radiation.
An authentication device as claimed in any preceding claim, wherein the emitted electromagnetic radiation has an intensity that is linearly dependent on the incident electromagnetic radiation.
An authentication device as claimed in any preceding claim, wherein the two-dimensional material is a direct band gap material.
An authentication device as claimed in any preceding claim, wherein the photons emitted by non-resonant photoluminescence of the substantially two-dimensional material have an energy that corresponds substantially to the band gap energy of the two dimensional material at the associated position in the operative area.
An authentication device as claimed in any preceding claim, wherein the band gap of the two dimensional material varies spatially across the operative area of the substantially two-dimensional material.
An authentication device as claimed in any preceding claim, wherein the band gap of the substantially two-dimensional material varies due to any of:
- lattice imperfections, edge defects, the shape and/or size of the two-dimensional material, the geometry of the two-dimensional material, and the interaction of the two-dimensional material with other layers of the device.
An authentication device as claimed in any preceding claim, wherein the band gap of the substantially two-dimensional material varies across the material, within the range 0 eV and 4 eV.
An authentication device as claimed in any preceding claim, wherein the substantially two-dimensional material emits electromagnetic radiation in the visible spectrum.
An authentication device as claimed in any preceding claim, wherein the substantially two-dimensional material is doped with impurities, which alter the band gap in certain regions of the operative area of the substantially two-dimensional material.
An authentication device as claimed in any preceding claim, wherein the substantially two-dimensional material comprises a plurality of flakes of said material.
An authentication device as claimed in any preceding claim, wherein the substantially two-dimensional material is encapsulated within, or laminated by, at least one layer of an optically transmissive, eg transparent, material.
An authentication device as claimed in any preceding claim, wherein the substantially two-dimensional material is any one of, or any combination of:
- graphene oxide, graphene and phosphorene.
An authentication device as claimed in any preceding claim, wherein the substantially two dimensional material is any one of, or any combination of, transition metal dichalcogenides, for example, molybdenum disulphide, molybdenum diselenide, tungsten disulphide and tungsten diselenide.
An authentication device as claimed in any preceding claim, wherein the substantially two dimensional material is any one of, or any combination of, group III-chalcogenides, for example Ga2X2 or In2X2, where X═S, Se, or Te.
An authentication device as claimed in any preceding claim, wherein the authentication device forms part of, or is integrated with, an article for which authentication is desired.
An article comprising an authentication device as claimed in any preceding claim.
Dependencies are inferred from the claim text.