Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/50—Sympathetic, colour changing or similar inks
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/30—Identification or security features, e.g. for preventing forgery
  • B42D25/36—Identification or security features, e.g. for preventing forgery comprising special materials
  • B42D25/378—Special inks
  • B42D25/382—Special inks absorbing or reflecting infrared light
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/30—Identification or security features, e.g. for preventing forgery
  • B42D25/36—Identification or security features, e.g. for preventing forgery comprising special materials
  • B42D25/378—Special inks
  • B42D25/387—Special inks absorbing or reflecting ultraviolet light
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/02—Printing inks
  • C09D11/03—Printing inks characterised by features other than the chemical nature of the binder
  • C09D11/037—Printing inks characterised by features other than the chemical nature of the binder characterised by the pigment
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/02—Printing inks
  • C09D11/10—Printing inks based on artificial resins
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/22—Luminous paints
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/85—Packages
  • H10H20/851—Wavelength conversion means
  • H10H20/8511—Wavelength conversion means characterised by their material, e.g. binder
  • H10H20/8512—Wavelength conversion materials

Definitions

• PHOSPHOR COMPOSITIONS AND ASSOCIATED SYSTEMS, DEVICES AND METHODS CROSS-REFERENCE TO RELATED APPLICATIONS [0001]
• the present application claims priority to U.S. Provisional Patent App. No. 63/379,136, filed October 11, 2023, the disclosure of which is incorporated herein by reference in entirety.
• TECHNICAL FIELD [0002]
• the present disclosure relates to phosphor compositions and associated systems, devices and methods.
• the phosphor compositions are used as unique identifiers to authenticate an object the phosphor composition is disposed on or embedded in.
• BACKGROUND [0003] Fraudulent or counterfeit goods exact a high cost on the global economy.
• Level 1 security includes overt features, such as tamper-evident labels, holograms, watermarks, or tactile relief patterns detectable by the bare human senses (e.g., sight, touch, and smell).
• Level 2 security includes covert features using ordinary devices, such as embedded microchips (e.g., radio frequency identification (RFID) chips) that can be read by a mobile phone or luminescent pigments that glow under a UV light source.
• RFID radio frequency identification
• Level 3 security includes covert security features using special/sophisticated devices, such as security fibrils or filaments embedded into a material that can be identified using dedicated detectors.
• Level 4 security features involve forensics, taggants, and laboratory testing, such as micro- or nano-patterned textures and/or marks that require high-resolution microscopes for detection (e.g., electron microscopy), as well as taggants with specific chemical compositions that require forensic elemental analysis (e.g., X-ray fluorescence, mass spectroscopy, nuclear magnetic resonance (NMR) spectroscopy for detection.
• Luminescent security inks are highly versatile and can serve as Level 1, 2, 3, or 4 security marks depending on the sophistication of their design and application.
• Luminescent security inks for authentication are known in the art in some cases, as documented by Rajchman et. al. in U.S. Patent No. 2,742,631 titled -1- 133143.8001.WO00/163936155.1 “Methods for recording and transmitting information using phosphors” and Berler in U.S. Patent No.3,614,430 titled “Fluorescent-ink-imprinted coded document and method and apparatus for use in connection therewith.”
• the methods in these patents proposed using spectral signatures of organic dyes and/or inorganic phosphors as security inks for authentication (i.e., Security Levels 1 and 2).
• quantum dots have a small Stokes shift (e.g., less than 50 nm) such that the emitted light overlaps with the absorption, which limits light outcoupling.
• Synthetic methods for preparing and purifying quantum dots typically involve expensive reagents and solvents, rendering them expensive with respect to inorganic phosphors and organic dyes.
• FIG. 1 is a schematic illustration of a system for creating a composite comprising a phosphor, in accordance with embodiments of the present technology.
• FIG.2 is a schematic illustration of a system for creating a substrate comprising a phosphor, in accordance with embodiments of the present technology.
• FIGS.3 and 4 are schematic illustrations of systems for detecting emitted light from a target, in accordance with embodiments of the present technology.
• FIG.5 is a flow chart for authenticating a target, in accordance with embodiments of the present technology.
• FIG. 6A is plot illustrating photoluminescence excitation (PLE) spectra and corresponding photoluminescence (PL) spectra for different phosphor compositions, in accordance with embodiments of the present technology.
• FIG. 6B is a plot illustrating PL spectra of different light emitting materials that include phosphors and dyes, in accordance with embodiments of the present technology.
• FIG. 7 is a plot illustrating PL decays of the phosphor compositions of FIG. 6A, in accordance with embodiments of the present technology.
• FIG. 8A is a dark-field image of a phosphor composition and FIG. 8B is a PL image of the phosphor composition of FIG.8A, in accordance with embodiments of the present technology.
• FIGS.9A–9C illustrate visualizations of a phosphor composition under different illuminations, in accordance with embodiments of the present technology.
• FIG. 10 is a plot illustrating PL spectra of phosphor compositions including different dopants, in accordance with embodiments of the present technology.
• FIG.11A is a scanning electron microscope (SEM) image of a phosphor composition without a protective shell, in accordance with embodiments of the present technology.
• FIG. 11B is a tunneling electron microscope (TEM) image of a single phosphor with a 50- nanometer protective shell and
• FIG. 11C is a portion of the TEM image of FIG. 11B, in accordance with embodiments of the present technology.
• SEM scanning electron microscope
• FIG. 11B is a tunneling electron microscope (TEM) image of a single phosphor with a 50- nanometer protective shell
• FIG. 11C is a portion of the TEM image of FIG. 11B, in accordance with embodiments of the present technology.
• a person skilled in the relevant art will understand that the features shown in the drawings are for purposes of illustrations, and variations, including different and/or additional features and arrangements thereof, are possible.
• Embodiments of the present technology attempt to address at least some of these deficiencies of the conventional technologies, by disclosing phosphors that have improved light conversion efficiency, relatively slow PL lifetimes, and relatively large effective Stokes Shifts that enable better light outcoupling and better detection for authentication purposes.
• phosphors of the present technology possess characteristically strong light absorption properties, and the ability to tune the onset of light absorption from 300–1000 nm, e.g., by changing the ratio of halide ions. Doing so enables embodiments of the present technology to utilize a variety of low-cost, off-the-shelf light sources to photoexcite the phosphors in a custom optical detection system.
• the luminescent species can be Yb 3+ dopant ions that exhibit characteristic f-f orbital luminescence in the near-infrared (NIR) spectrum around 980 nm, which is invisible to the naked human eye and thus enables covert security marking applications.
• other dopant ions that exhibit luminescence in the NIR spectrum e.g., Nd 3+ and Tm 3+
• the light-conversion process of phosphors of the present technology has exhibited photon conversion as high as 95%, and the NIR photoluminescence lifetime is tunable based on composition, e.g., to a millisecond (ms) timescale.
• FIG. 1 is a schematic illustration of a system 100 for creating a composite comprising a phosphor, in accordance with embodiments of the present technology.
• the system 100 includes a mixer 105 configured to receive a phosphor 101 (e.g., a phosphor composition or first composition) and a solvent 102 (e.g., a second composition).
• the mixer 105 can mix the phosphor 101 and the solvent 102 to form a composite 106.
• the composite 106 can be configured to be manipulated into a desired pattern, e.g., via processes including 2-dimensional (2D) printing, 3D printing, inkjet printing, screen printing, intaglio printing, stamping, spraying, spin coating, and/or extruding.
• the composite 106 can be transferred to a target (to be authenticated) via one or more of these processes.
• the composite 106 can be an ink comprising phosphor, PMMA, and toluene, which is stamped onto a target (e.g., a cotton paper) using a patterned rubber stamp (as shown in FIGS.9A–9C). Once the ink dries and/or toluene evaporates, the phosphor is embedded in the PMMA matrix on the target.
• a target e.g., a cotton paper
• a patterned rubber stamp as shown in FIGS.9A–9C
• the phosphor 101 can comprise a chemical formula of one of M:ABX3, M:AB2X5, M:A4BX6, M:C2DX5, or M:A2CDX6, M:A8CDX12, M:A2C2D2X10, wherein: (i) A is a cation comprising lithium (Li + ), sodium (Na + ), potassium (K + ), rubidium (Rb + ), caesium (Cs + ), methylammonium, formamidinium, guanidinium, or mixtures thereof, (ii) B is a cation comprising lead (Pb 2+ ), tin (Sn 2+ ), germanium (Ge 2+ ), cadmium (Cd 2+ ), magnesium (Mg 2+ ), titanium (Ti 2+ ), mercury (Hg 2+) or mixtures thereof, (iii) C is a cation comprising silver (Ag + ), copper (Cu + ), tin
• phosphors of the present technology can comprise M:ABX 3 , M:A 2 CDX 6 , M:CsPbX 3 , MCs 2 AgBiX 6 , or MCs 2 Ag 1-x Na x Bi 1-y In y X 6 .
• phosphors of the present technology can comprise a Yb 3+ -doped CsPb(Cl 1-x Br x ) 3 phosphor powder. As explained herein, such a powder can be integrated into inks and polymer precursors for printing and casting into composite security marks that retain the photoluminescence properties (e.g., excitation spectrum, emission spectrum, quantum yield, and lifetime) of the starting phosphor powder.
• the photoluminescence properties of the phosphor composites do not degrade for at least 2, 4, 6, 8, 10, 12 or 14 days under ambient conditions.
• the phosphor 101 can be a powder, a film, a coating, a pellet, a bead, nanocrystals, or microcrystals.
• the phosphor 101 can have a -5- 133143.8001.WO00/163936155.1 mean particle diameter of 1 nanometer (nm)–100 micrometers ( ⁇ m), or any value therebetween (e.g., 100 nm, 40 ⁇ m, 97 ⁇ m, etc.).
• the phosphor 101 is altered such that the phosphor 101 has a desired mean particle diameter, e.g., by sieving, grinding, milling, melting, and/or centrifuging the phosphor 101 to form the desired mean particle diameter, and/or based on a desired application or end use.
• phosphors are conformally coated with a barrier coating, such as a metal- oxide coating, to improve various properties of the phosphor including, but not limited to, emission brightness, photoluminescence (PLQY), and durability.
• the barrier coating can comprise silicon dioxide (SiO2), aluminum dioxide (Al2O3), titanium dioxide (TiO2), and/or hafnium dioxide or hafnium (IV) oxide (HfO2).
• the barrier coatings comprise multiple layers of these materials (e.g., Al2O3/TiO2).
• the barrier coatings can improve the stability of the phosphors towards environmental degradation (e.g., from water and oxygen exposure), and multi-layer coatings can provide enhanced stability.
• the barrier coating(s) can be deposited onto a phosphor particle using chemical vapor deposition (CVD) techniques such as atomic layer deposition (ALD).
• CVD chemical vapor deposition
• ALD atomic layer deposition
• the M can be a dopant of the crystalline lattice and/or M can substitute for B or D in the crystalline lattice or on the crystalline surface. Additionally or alternatively, in some embodiments, M comprises no more than 49% of a molar ratio of M/(B+M) or M/(D+M).
• the phosphor 101 when exposed to light (e.g., a pulsed light) from a light source, can be tailored to absorb light having a wavelength of 250–700 nm and/or emit light or electromagnetic radiation undetectable by the human eye.
• the phosphor 101 when exposed to the light from the light source, the phosphor 101 emits electromagnetic radiation having a lower energy than that of the light source. Additionally or alternatively, the phosphor 101 may only emit electromagnetic radiation from a portion of the phosphor 101, and or different portions of the phosphor 101 may emit electromagnetic radiation at different wavelengths. For example, in such embodiments, a first portion of the phosphor 101 may emit electromagnetic radiation in response to light at a first predetermined wavelength and a second portion of the phosphor 101 different than the first portion may emit electromagnetic radiation at a second predetermined wavelength different than the first predetermined wavelength.
• the electromagnetic radiation emitted from the phosphor 101 in response to the light can be due to band-edge recombination and/or dopant emission.
• the phosphor 101 can have an absorption maxima that does not overlap its emission maxima.
• the difference between the absorption maxima and the emission maxima can be at least 50 nanometers (nm), 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm, 1000 nm, 1050 nm, 1100 nm, 1150 nm, 1200 -6- 133143.8001.WO00/163936155.1 nm, or 1250 nm.
• the phosphor 101 can have a Stokes Shift of at least 50 nanometers (nm), 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm, 1000 nm, 1050 nm, 1100 nm, 1150 nm, 1200 nm, or 1250 nm.
• the lack of overlap and/or a larger Stokes shift enables more light to be detected by the light detector(s).
• FIG. 2 is a schematic illustration of a system 200 for creating a substrate 210 comprising a phosphor, in accordance with embodiments of the present technology.
• the phosphor 101 described with reference to FIG. 1 is combined with and/or embedded in a matrix 205, which can then be further processed with (e.g., woven into) another matrix to form a substate 210.
• FIG. 3 is a schematic illustration of a system 300 for detecting emitted light from a target 303, in accordance with embodiments of the present technology.
• the target 303 includes a substate 330 and a composite 335 (e.g., the composite 106; FIG. 1) disposed over the substrate 330.
• the composite 335 can include a matrix or solvent 337 (e.g., the solvent 102; FIG.
• the system 300 includes a controller 305, and components electrically coupled to (e.g., in communication with) and controllable by the controller 305.
• the components can include a light source 310 configured to be positioned over and emit light 311 toward the target 303, and one or more light detectors configured to detect electromagnetic radiation emanated from the target 303 in response to the emitted light 311 from the light source 310.
• the one or more light detectors can include a time-resolved photoluminescence (TRPL) detector 315 configured to measure TRPL, and/or a spectrally-resolved broadband PL (SRPL) detector 320 configured to measure SRPL.
• the system 300 only includes one of the TRPL detector 315 or SRPL detector 320 (i.e., one of the TRPL detector 315 or SRPL detector 320 is omitted).
• the system 300 can further include a filter 316 coupled to the TRPL detector 315 and configured to inhibit particular wavelengths of light from being detected by the TRPL detector 315 and/or obtained by the controller 305.
• the light source 310 is configured to emit light 311 toward the target 303.
• the light 311 from the light source 310 can be pulsed (e.g., turned on and off quickly) to ensure the emission, -7- 133143.8001.WO00/163936155.1 light, or electromagnetic radiation 336 (“electromagnetic radiation 336”) emanated from the target 303 or composite 335 can be detected without extra light interference, and/or to give time for the emission decay process to occur.
• properties of the electromagnetic radiation 336 can be detected via the light detectors at a moment when the light source is not emitting the light 311.
• the light source 310 can comprise a 200–700 nm laser diode (e.g., a 405 nm laser diode).
• the light source 310 can comprise gallium nitride and/or indium gallium nitride quantum wells.
• the TRPL detector 315 is configured to measure an intensity of the electromagnetic radiation 336, and/or a change (e.g., a decay) in intensity of the electromagnetic radiation 336 over a time period (e.g., less than 20 ms). For example, as explained in more detail with reference to FIG.7, the TRPL detector 315, and/or the controller 305 in communication with the TRPL detector 315, can determine changing intensities of the electromagnetic radiation 336 at various times (e.g., 1 ms, 2 ms, 3 ms, etc.) over the time period to produce a PL decay curve.
• the produced curve can then be fitted against a baseline curve to produce an output indicating how well the produced curve corresponds to the baseline curve.
• the output is used to authenticate the target 303 and/or substrate 330. For example, if the output is within a predetermined range for the target 303, then that target 303 can be authenticated or deemed not unauthentic, and if the output is outside of the predetermined range for the target 303, then the target 303 can be deemed unauthentic.
• the SRPL detector 320 is configured to measure a wavelength (e.g., color) and/or PL emission spectrum of the electromagnetic radiation 336 of the target 303 or composite 335.
• the SRPL detector 320 can produce an output corresponding to one or more (e.g., two, three, four, etc.) emission maximums of the emission spectra.
• the measured output, or one or more emission maximums can be compared to a baseline value, e.g., corresponding to an authenticated target.
• the output is used to authenticate the target 303 and/or substrate 330. For example, if the output is within a predetermined range for the target 303, then that target 303 can be authenticated, and if the output is outside of the predetermined range for the target 303, then the target 303 can be deemed unauthentic.
• the light source 310 can emit the light 311 toward the target 303 causing some of the light 311 to be absorbed by the target 303 and the electromagnetic radiation 336 to be emanated away from the target 303 toward the one or more detectors (i.e., the TRPL detector 315 and/or the SRPL detector 320).
• the TRPL detector 315 and SRPL detector 320 can each obtain independent property data or measurements of the electromagnetic radiation 336, and such data can be used (e.g., by the controller 305) to authenticate the target 303.
• FIG. 4 is a schematic illustration of the system 300 for detecting emitted light from and/or -8- 133143.8001.WO00/163936155.1 authenticating a target 403, in accordance with embodiments of the present technology.
• the target 403 includes a substrate 430 (e.g., the substrate 210; FIG. 2), a matrix 437 (e.g., the matrix 205; FIG. 2) embedded in the substrate, and a phosphor 436 (e.g., the phosphor 101; FIGS. 1 and 2) embedded in or attached to the matrix 437.
• FIG.5 is a flow chart 500 including a method for authenticating a target (e.g., the target 303/403; FIGS.
• the light source can emit light toward the security mark to cause it, or more particularly the phosphor of the security mark, to emanate electromagnetic radiation away from the security mark.
• the process continues by measuring (e.g., via the TRPL detector 315; FIGS. 3 and 4) a PL lifetime or TRPL of the emanated electromagnetic radiation from the phosphor (process portion 515). If the PL lifetime or TRPL of the emanated electromagnetic radiation is not within a first predetermined range, the object is not authenticated (process portion 540) and the authentication process can end.
• the process can proceed to measure a PL spectrum or SRPL (e.g., via the SRPL detector 320; FIGS. 3 and 4) of the emanated electromagnetic radiation from the phosphor (process portion 525). If the PL spectrum or SRPL of the electromagnetic radiation has an emission intensity and/or relative intensity ratios outside of a second predetermined range, the object is not authenticated (process portion 540) and the authentication process can end. If the PL spectrum or SRPL of the electromagnetic radiation has an emission intensity and/or relative intensity ratios within the second predetermined range, the object is authenticated and the authentication process can end. III. Experimental Results [0042] FIG.
• 6A includes plots 605, 610, 615 illustrating photoluminescence excitation (PLE) spectra (dashed lines) and corresponding photoluminescence (PL) spectra (solid lines) for different phosphor compositions, in accordance with embodiments of the present technology.
• the PLE spectra corresponds to an -9- 133143.8001.WO00/163936155.1 absorption spectra and the PL spectra corresponds to a emission spectra.
• the PLE for each of the plots 605, 610, 615 was monitored at PL peak maximums.
• Plot 605 includes a PL spectra 606 and PLE spectra 607 for a first phosphor composition (“Phosphor 1”)
• Plot 610 includes a PL spectra 611 and PLE spectra 612 for a second phosphor composition (“Phosphor 2”)
• Plot 615 includes a PL spectra 616 and PLE spectra 617 for a third phosphor composition (“Phosphor 3”).
• the PL and PLE i.e., intensity
• the PL maximums for each of Phosphor 1, Phosphor 2 and Phosphor 3 occurs at a wavelength of about 1000 nm.
• the same detector e.g., the SRPL detector 320; FIGS. 3 and 4
• the PLE spectra and corresponding PL spectra for each of Phosphor 1, Phosphor 2 and Phosphor 3 exhibit no overlap, and more specifically include a difference of about 500 nm for Phosphor 1, about 650 nm for Phosphor 2, and about 650 nm for Phosphor 3.
• FIG. 6B is a plot 650 illustrating PL spectra of different light emitting materials that include phosphors and dyes, in accordance with embodiments of the present technology.
• the plot 650 includes PL spectra 655 for Anthracene Dye (“Anthracene spectra 655”) corresponding to a purple dye, PL spectra 660 for Coumarin 540A Dye (“Coumarin spectra 660”) corresponding to a green dye, PL spectra 665 for Rhodamine 6G Dye (“Rhodamine spectra 665”) corresponding to a gold dye, PL spectra 670 for Rhodamine 101 Dye (“Rhodamine spectra 670”) corresponding to a red dye, and PL spectra 675 for Phosphor 3.
• FIG. 7 is a plot 700 illustrating PL decays of the phosphor compositions of FIG. 6A, in accordance with embodiments of the present technology.
• the plot 700 includes a first decay curve 705 corresponding to Phosphor 1, a second decay curve 710 corresponding to Phosphor 2, and a third decay curve corresponding to Phosphor 3.
• Each of the first, second, and third decay curves 705, 710, 715 are unique and distinguishable from one another, with Phosphor 1 having a lifetime of about 0.94 ms, Phosphor 2 having a lifetime of about 1.30 ms, and Phosphor 3 having a lifetime of about 1.80 ms.
• the first, -10- 133143.8001.WO00/163936155.1 second, and third decay curves 705, 710, 715 can correspond to the curves described herein that are generated by the TRPL detector (e.g., the TRPL detector 315; FIGS.3 and 4).
• FIG. 8A is a dark-field image of a phosphor composition
• FIG. 8B is a PL image of the phosphor composition of FIG.8A, in accordance with embodiments of the present technology.
• the dark-field image of the phosphor composition of FIG.8A has a yellow color
• the PL image of the same phosphor composition in FIG.8B has emission around 1000nm (shown as a blue color).
• FIGS. 9A–9C illustrate a phosphor composition under different illuminations, in accordance with embodiments of the present technology. More specifically, FIG.9A illustrates the phosphor composition under room light using a standard camera, FIG.9B illustrates the phosphor composition under ultraviolet (UV) light using the standard camera, and FIG.9C illustrates the phosphor composition under UV light using a NIR camera. As shown in FIGS.9A–9C, the phosphor composition emits a different electromagnetic radiation for each condition, with the room light of FIG.
• a light detector e.g., the SRPL detector 320; FIGS. 3 and 4
• FIG. 10 is a plot 1000 illustrating PL spectra of phosphor compositions including different dopants, in accordance with embodiments of the present technology.
• the plot 1000 includes PL spectra 1010 for a Tm 3+ -doped phosphor (“Phosphor 4”), PL spectra 1020 for a Nd 3+ -doped phosphor (“Phosphor 5”), and PL spectra 1030 for a Yb 3+ -doped phosphor (“Phosphor 6”),
• the different phosphors e.g., Phosphors 1-3 of FIG.6A and Phosphors 4-6 of FIG 10
• FIG.11A is a scanning electron microscope (SEM) image of a phosphor composition without a protective shell
• FIGS. 11B and 11C are images of a phosphor composition with a barrier coating (e.g., a protective shell), in accordance with embodiments of the present technology.
• the barrier coating can comprise silicon dioxide (SiO2), aluminum dioxide (Al2O3), titanium dioxide (TiO2), and/or hafnium dioxide or hafnium (IV) oxide (HfO2).
• the barrier coatings comprise multiple layers of these materials (e.g., Al2O3/TiO2).
• the barrier coatings can improve the stability of the phosphors towards environmental degradation (e.g., from water and oxygen exposure), and multi-layer coatings can provide enhanced stability.
• the coatings can be deposited using chemical vapor deposition, atomic layer deposition, or other deposition methods. IV.
• references herein to “one embodiment,” “an embodiment,” “some embodiments” or similar formulations means that a particular feature, structure, operation, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present technology.
• the appearances -12- 133143.8001.WO00/163936155.1 of such phrases or formulations herein are not necessarily all referring to the same embodiment.
• various particular features, structures, operations, or characteristics may be combined in any suitable manner in one or more embodiments.
• a range of “1 to 10” includes any and all subranges between (and including) the minimum value of 1 and the maximum value of 10, i.e., any and all subranges having a minimum value of equal to or greater than 1 and a maximum value of equal to or less than 10, e.g., 5.5 to 10.

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• 2023
  • 2023-10-06 WO PCT/US2023/076290 patent/WO2024081566A1/en not_active Ceased
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