# US 2013/0153789 A1 · Luminescent materials, articles incorporating luminescent materials, and methods for performing article authentication > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153789 A1 - Document ID: US20130153789A1 - Status: Published application - Kind: A1 - Application number: 13/708,210 - Filed: 2012-12-07 - Published: 2013-06-20 - Earliest claimed: 2011-12-19 - Assignees: Honeywell International Inc. - Inventors: Karl J. Smith; Howard A. Fraenkel - Web page: https://patentgrep.com/patent/US20130153789A1 ## CPC - G01N 21/63: optically excited - G01N 21/6408: {with measurement of decay time, time resolved fluorescence} - G01N 21/6428: {Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" (in vivo A61B5/00; immunoassay G01N33/53)} - G07D 7/1205: Testing spectral properties - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G07D: HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING ## Abstract Embodiments of luminescent materials and articles include first and second particles of first and second inorganic host lattices. The first particles are capable of producing first emissions having one or more first emission peaks at one or more first wavelengths. The first emissions have a first decay half-life that is long enough for the first emissions to be perceptible to the human eye for a first time period that begins when appropriate excitation of the luminescent material is discontinued. The second particles are capable of producing second emissions having one or more second emission peaks at one or more second wavelengths. The second emissions have a second decay half-life that is longer than the first decay half-life by a decay time difference that is sufficient for the second emissions to be perceptible to the human eye for a second time period that begins after the first time period. ## Claims ### Claim 1 A luminescent material comprising: first particles of a first inorganic host lattice having at least one first substance dispersed within the first inorganic host lattice, wherein the first particles are capable of producing first emissions having one or more first emission peaks at one or more first wavelengths, wherein the one or more first wavelengths include at least one first visible wavelength within the visible spectrum, and the first emissions at the first visible wavelength have a first decay half-life that is long enough for the first emissions at the first visible wavelength to be perceptible to the human eye for a first time period that begins when appropriate excitation of the luminescent material is discontinued; and second particles of a second inorganic host lattice having at least one second substance dispersed within the second inorganic host lattice, wherein the second particles are capable of producing second emissions having one or more second emission peaks at one or more second wavelengths, wherein the one or more second wavelengths include at least one second visible wavelength within the visible spectrum, wherein the second visible wavelength is different from the first visible wavelength, and the second emissions at the second visible wavelength have a second decay half-life that is longer than the first decay half-life by a decay time difference that is sufficient for the second emissions at the second visible wavelength to be perceptible to the human eye for a second time period that begins after the first time period. ### Claim 2 (depends on 1) The luminescent material of claim 1, wherein the first visible wavelength corresponds to a first color, and the second visible wavelength corresponds to a second color that is different from the first color, and wherein the first color and the second color are different colors selected from a group consisting of red, orange, yellow, green, blue, and violet. ### Claim 3 (depends on 1) The luminescent material of claim 1, wherein the first visible wavelength and the second visible wavelength are different by at least 2 nanometers. ### Claim 4 (depends on 1) The luminescent material of claim 1, wherein the first inorganic host lattice and the second inorganic host lattice are selected from a group consisting of an oxide, a fluoride, a sulfide, an oxysulfide, a halide, a borate, a gallate, a phosphate, a vanadate, an oxyhalide, an aluminate, a molybdate, a tungstate, a garnet, a germanate, a chlorophosphate, a niobate, and mixtures thereof. ### Claim 5 (depends on 1) The luminescent material of claim 1, wherein the first inorganic host lattice and the second inorganic host lattice are selected from a group consisting of BaMg2Al16O27, ZnS, Y3Al5O12 (YAG), Y2O2S, Gd3Ga5O12, Y3Ga5O12 (YGG), Y3Fe5O12 (YIG), YIG:YGG, and mixtures thereof. ### Claim 6 (depends on 1) The luminescent material of claim 1, further comprising: one or more media within which the first particles and the second particles are incorporated, wherein the one or more media are selected from a group consisting of an ink, an ink additive, a glue, a liquid, a gel, a polymer, a slurry, a plastic, plastic base resin, a glass, a ceramic, a metal, a textile, wood, fiber, paper pulp, paper, and mixtures thereof. ### Claim 7 (depends on 1) The luminescent material of claim 1, wherein the first inorganic host lattice and the second host inorganic host lattice are the same. ### Claim 8 (depends on 1) The luminescent material of claim 1, wherein the first inorganic host lattice and the second inorganic host lattice are different. ### Claim 9 (depends on 1) The luminescent material of claim 1, further comprising: one or more additional particles of one or more additional inorganic host lattices having one or more additional substances dispersed within the one or more additional inorganic host lattices, wherein the one or more additional particles are capable of producing one or more additional emissions having one or more additional emission peaks at one or more additional wavelengths, wherein the one or more additional wavelengths includes one or more additional visible wavelengths within the visible spectrum, wherein the one or more additional visible wavelengths are different from the first visible wavelength and the second visible wavelength, and the additional emissions at the one or more additional visible wavelengths have one or more additional decay half-lives that are different from the first decay half-life and the second decay half-life by one or more decay time differences that are sufficient for the additional emissions at the one or more additional visible wavelengths to be perceptible to the human eye for one or more additional time periods that begin after the first time period and the second time period. ### Claim 10 (depends on 1) The luminescent material of claim 1, wherein the first decay half-life is in a range of about 10 millisecond to about 100 milliseconds, and the second decay half-life is at least about 50 milliseconds. ### Claim 11 (depends on 1) The luminescent material of claim 1, wherein the second decay half-life is at least 10 milliseconds longer than the first decay half-life. ### Claim 12 (depends on 1) The luminescent material of claim 1, wherein the at least one first substance and the at least one second substance each include ions or atoms of elements selected from a group consisting of aluminum, chromium, manganese, iron, copper, silver, tin, antimony, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lead, and mixtures thereof. ### Claim 13 An article comprising: first particles of a first inorganic host lattice having at least one first substance dispersed within the first inorganic host lattice, wherein the first particles are capable of producing first emissions having one or more first emission peaks at one or more first wavelengths, wherein the one or more first wavelengths includes at least one first visible wavelength within the visible spectrum, and the first emissions at the first visible wavelength have a first decay half-life that is long enough for the first emissions at the first visible wavelength to be perceptible to the human eye for a first time period that begins when appropriate excitation of the luminescent material is discontinued; and second particles of a second inorganic host lattice having at least one second substance dispersed within the second inorganic host lattice, wherein the second particles are capable of producing second emissions having one or more second emission peaks at one or more second wavelengths, wherein the one or more second wavelengths includes at least one second visible wavelength within the visible spectrum, wherein the second visible wavelength is different from the first visible wavelength, and the second emissions at the second visible wavelength have a second decay half-life that is longer than the first decay half-life by a decay time difference that is sufficient for the second emissions at the second visible wavelength to be perceptible to the human eye for a second time period that begins after the first time period. ### Claim 14 (depends on 13) The article of claim 13, wherein the first inorganic host lattice and the second inorganic host lattice are selected from a group consisting of an oxide, a fluoride, a sulfide, an oxysulfide, a halide, a borate, a gallate, a phosphate, a vanadate, an oxyhalide, an aluminate, a molybdate, a tungstate, a garnet, a germanate, a chlorophosphate, a niobate, and mixtures thereof. ### Claim 15 (depends on 13) The article of claim 13, further comprising: one or more additional particles of one or more additional inorganic host lattices having one or more additional substances dispersed within the one or more additional inorganic host lattices, wherein the one or more additional particles are capable of producing one or more additional emissions having one or more additional emission peaks at one or more additional wavelengths, wherein the one or more additional wavelengths includes one or more additional visible wavelengths within the visible spectrum, wherein the one or more additional visible wavelengths are different from the first visible wavelength and the second visible wavelength, and the additional emissions at the one or more additional visible wavelengths have one or more additional decay half-lives that are different from the first decay half-life and the second decay half-life by one or more decay time differences that are sufficient for the additional emissions at the one or more additional visible wavelengths to be perceptible to the human eye for one or more additional time periods that begin after the first time period. ### Claim 16 (depends on 13) The article of claim 13, further comprising: a substrate; and one or more features, wherein the first particles and the second particles are included in the one or more features. ### Claim 17 (depends on 13) The article of claim 13, further comprising: one or more media, wherein the first particles and the second particles are included in the one or more media. ### Claim 18 (depends on 13) The article of claim 13, further comprising: a first medium, wherein the first particles are included in the first medium; and a second medium, wherein the second substance are included in the second medium. ### Claim 19 (depends on 13) The article of claim 13, wherein the article includes multiple, spatially distinct regions, and wherein a first region of the multiple regions includes a first ratio of the first particles to the second particles, and a second region of the multiple regions includes a second ratio of the first particles to the second particles, wherein the first ratio and the second ratio are different. ### Claim 20 (depends on 13) The article of claim 13, further comprising: a substrate, wherein the first particles and the second particles are included in the substrate. ### Claim 21 (depends on 13) The article of claim 13, further comprising: a substrate, wherein the first particles are included in the substrate; and a feature applied to or embedded within the substrate, wherein the second particles are included in the feature. ### Claim 22 (depends on 13) The article of claim 13, wherein the article is an article selected from a group consisting of an identification card, a driver's license, a passport, identity papers, a banknote, a check, a document, a paper, a stock certificate, a packaging component, a credit card, a bank card, a label, a seal, a postage stamp, a token, a liquid, a human, an animal, and a biological sample. ### Claim 23 A method for authenticating an article, the method comprising the steps of: providing excitation energy to the article by moving an article and an excitation source with respect to each other; determining whether emissions from a first portion of the article correspond to a first color and emissions from a second portion of the article correspond to a second color that is different from the first color; and when the emissions from the first portion of the article and the emissions from the second portion of the article simultaneously do not correspond to the first color and the second color, determining that the article is not authentic. ### Claim 24 (depends on 23) The method of claim 23, wherein: providing the excitation energy comprises moving the excitation source and a surface of the article with respect to each other so that the excitation source provides the excitation energy along a track on the surface, wherein the excitation energy is provided to the first portion of the track during a first time period, and the excitation energy is provided to a second portion of the track during a subsequent, second time period. ### Claim 25 (depends on 23) The method of claim 23, wherein the excitation source is a light emitting diode. ### Claim 26 (depends on 23) The method of claim 23, wherein the first color and the second color are different colors selected from a group consisting of red, orange, yellow, green, blue, and violet. ### Claim 27 (depends on 23) The method of claim 23, wherein the first portion and the second portion are selected from a group consisting of a region of a substrate of the article, a region of a layer of the article, a surface-applied feature of the article, and an embedded feature of the article.