JP2012514071A - Method for encapsulating nanocrystals and the resulting composition - Google Patents

Abstract

  The present invention provides a method for hermetically sealing luminescent nanocrystals, as well as compositions and containers comprising hermetically sealed luminescent nanocrystals. By hermetically sealing the luminescent nanocrystals, improved lifetime and emission can be achieved.

Description

  The present invention relates to a method for hermetically sealing luminescent nanocrystals and a hermetically sealed nanocrystal composition. The present invention further provides microspheres comprising luminescent nanocrystals and methods for making microspheres.

  Luminescent nanocrystals exposed to air and moisture are oxidatively damaged, often resulting in a loss of luminescence. The use of luminescent nanocrystals in applications such as downconversion layers, filtering layers, etc. often exposes luminescent nanocrystals to high temperatures, high intensity light, environmental gases and moisture. These factors, coupled with the long emission lifetime requirements in these applications, often limit the use of luminescent nanocrystals or require frequent replacement.

  Accordingly, there is a need for methods and compositions that can hermetically seal luminescent nanocrystals, thereby extending service life and increasing luminescence intensity. The present invention satisfies these needs.

  The present invention provides methods and compositions for hermetically sealing luminescent nanocrystals. Compositions prepared in accordance with the present invention can be applied to a variety of applications, and the methods of the present invention allow for the preparation of hermetically sealed nanocrystalline compositions of various shapes and configurations.

  In one embodiment, the present invention provides a method of hermetically sealing one or more compositions comprising a plurality of luminescent nanocrystals. In an exemplary embodiment, a first substrate is provided and one or more compositions comprising a plurality of luminescent nanocrystals are disposed on the first substrate (eg, by screen printing). The second substrate is disposed on the first substrate so as to cover the composition of luminescent nanocrystals. The first and second substrates are then sealed.

  In an exemplary embodiment, the first and second substrates are glass substrates, and preferably the substrate has one or more recesses formed therein. In further embodiments, the first substrate further includes a third substrate having one or more recesses formed therein.

  Preferably, the luminescent nanocrystals for use in the practice of the present invention are core-shell luminescent nanocrystals, such as CdSe / ZnS, CdSe / CdS or InP / ZnS nanocrystals, preferably having a size of about 1 to 10 nm.

  Preferably, the first and second substrates are sealed with a polymer sealant such as an epoxy sealant. In an exemplary embodiment, the luminescent nanocrystal composition is cured prior to encapsulation. In suitable embodiments, the compositions are separated from each other after sealing the first and second substrates.

The method of the present invention can further include disposing a barrier layer on the first and second substrates, such as an inorganic material layer, for example, a layer of SiO ₂ , TiO ₂ or AlO ₂ . The barrier layer is preferably arranged by atomic layer deposition or sputtering.

  In a further embodiment, the method of the present invention includes the formation of one or more recesses in and / or on the first substrate. One or more compositions comprising a plurality of luminescent nanocrystals are then placed in the recesses and, prior to sealing, on the first substrate such that the second substrate covers the luminescent nanocrystal composition. Placed in.

  In an exemplary embodiment, the first substrate is etched to form one or more recesses. In a further embodiment, a third substrate having one or more recesses formed therein is disposed on the first substrate. In a further embodiment, a third substrate is disposed on the first substrate and one or more recesses are etched into the third substrate. In another further embodiment, the third substrate is disposed on the first substrate so as to form one or more recesses on the surface of the first substrate.

  The present invention further provides hermetically sealed compositions prepared by various methods described throughout.

  In a further embodiment, the present invention provides microspheres. Preferably, the microsphere comprises a central region, a first layer on the outer surface of the central region, a first layer comprising one or more luminescent nanocrystals, and a barrier layer on the outer surface of the first layer. Including.

Suitably, the central region of the microsphere comprises silica and the first layer comprises an inorganic material such as silica or titanium. Exemplary luminescent nanocrystals including core-shell nanocrystals are described in full range. Preferably, the barrier layer _comprises SiO 2, TiO _2, or AlO inorganic material layer, such as _2.

  In an exemplary embodiment, the microsphere has a diameter of less than about 500 microns, preferably less than about 10 microns, and more preferably less than about 1 micron.

  The present invention further provides a method of forming microspheres. Preferably, a particle comprising a first inorganic material is provided, wherein the particle is contacted with a composition comprising a precursor of a second inorganic material and one or more luminescent nanocrystals. A peripheral region is formed on the outer surface of the particle, and the peripheral region includes a second inorganic material and a luminescent nanocrystal. A barrier layer is then disposed on the outer surface of the peripheral region.

  Additional features and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by the structure and particularly pointed out in the written description and claims hereof as well as the appended drawings.

  It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the claimed invention.

  The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the present invention, and together with the description, explain the principles of the invention and allow those skilled in the art to understand the invention. Helps to implement and use.

2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 shows a flowchart of a method for hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. 2 illustrates a method of hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. FIG. 4 illustrates separating hermetically sealed luminescent nanocrystals according to one embodiment of the present invention. FIG. 4 illustrates separating hermetically sealed luminescent nanocrystals according to one embodiment of the present invention. FIG. 4 illustrates separating hermetically sealed luminescent nanocrystals according to one embodiment of the present invention. 2 shows a flowchart of a method for hermetically sealing a luminescent nanocrystal according to an embodiment of the present invention. Fig. 3 shows a microsphere according to an embodiment of the present invention. 2 shows a flow chart of a method for preparing microspheres according to one embodiment of the present invention.

  Next, the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, like reference numbers indicate identical or functionally similar elements.

  It is understood that the specific embodiments shown and described herein are examples of the present invention and that these embodiments are not intended to limit the scope of the invention in any way. Should. In fact, for simplicity, conventional electronics, manufacturing, semiconductor devices, and nanocrystal, nanowire (NW), nanorod, nanotube and nanoribbon technologies, and other functional aspects of the system (and the configuration of the individual operating components of the system) Element) may not be described in detail herein.

  The present invention provides various compositions comprising nanocrystals including luminescent nanocrystals. Various properties of the luminescent nanocrystals, including absorption properties, emission properties and refractive index properties can be adjusted and adjusted for different applications. As used herein, the term “nanocrystal” refers to a nanostructure that is substantially single crystal. The nanocrystal has at least one region or characteristic dimension having a dimension from less than about 500 nm to less than about 1 nm. As used herein, “about” when referring to a numerical value means a value that is ± 10% of the stated value (eg, “about 100 nm” ranges from 90 nm to 110 nm in magnitude). Included). It will be readily appreciated by those skilled in the art that the terms “nanocrystal”, “nanodot”, “dot” and “quantum dot” represent similar structures, and these terms are used interchangeably herein. . The invention further encompasses the use of polycrystalline or amorphous nanocrystals. As used herein, the term “nanocrystal” further encompasses “luminescent nanocrystals”. As used herein, the term “luminescent nanocrystal” means a nanocrystal that emits light when excited by an external energy source (preferably light). As used herein when describing hermetic sealing of nanocrystals, it should be understood that in preferred embodiments, the nanocrystals are luminescent nanocrystals.

  Typically, the characteristic dimension region is along the smallest axis of the structure. The material properties of the nanocrystals can be substantially uniform, or can be non-uniform in certain embodiments. The optical properties of nanocrystals can be determined by their particle size, chemistry or surface composition. The ability to adjust the size of the luminescent nanocrystals to a range of about 1 nm to about 15 nm allows the light emission range within the entire light spectrum to provide great versatility in color rendering. Particle encapsulation provides robustness against chemical and UV degradation agents.

Nanocrystals used in the present invention, including luminescent nanocrystals, can be produced using any method known to those skilled in the art. Suitable methods and exemplary nanocrystals are described in US Patent Application No. 2008/0237540, US Patent No. 7,374,807, US Patent Application No. 10 / 796,832 filed March 10, 2004. U.S. Patent No. 6,949,206, and U.S. Provisional Patent Application No. 60 / 578,236 filed June 8, 2004. The disclosures of each of these documents are each hereby incorporated by reference in their entirety. The nanocrystals used in the present invention can be made from any suitable material, including inorganic materials, more preferably inorganic conductors or semiconductor materials. Suitable semiconductor materials include those disclosed in US patent application Ser. No. 10 / 796,832, and any type of semiconductor including II-VI, III-V, IV-VI, and IV semiconductors. including. Suitable semiconductor materials include, but are not limited to, Si, Ge, Sn, Se, Te, B, C (including diamond), P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si ₃ N ₄ , Ge ₃ N ₄ , Al ₂ O ₃ , (Al, Ga, In) 2 (S, Se, Te) 3, Al 2 CO, and They comprise suitable combinations of species over the semiconductor.

  In certain embodiments, the semiconductor nanocrystal can include a dopant from the group consisting of a p-type dopant or an n-type dopant. Nanocrystals useful in the present invention can further comprise II-VI or III-V semiconductors. Examples of II-VI or III-V semiconductor nanocrystals are any combination of Group II elements of the Periodic Table such as Zn, Cd, Hg and any Group VI element such as S, Se, Te, Po, etc. , And any combination of Group III elements of the periodic table such as B, Al, Ga, In, Tl and any group V element such as N, P, As, Sb, Bi.

  Nanocrystals useful in the present invention, including luminescent nanocrystals, can further include ligands that are conjugated, co-operative, associated, or attached to the surface of the nanocrystal as described throughout. Suitable ligands include any known to those skilled in the art, including those disclosed in US Pat. No. 7,374,807, US Pat. No. 6,949,206 and US Provisional Patent Application 60 / 578,236. Including a group of ligands. The disclosures of each of these documents are each incorporated herein by reference. The use of such ligands can enhance the ability of nanocrystals to be incorporated into various solvents and matrices including polymers. Increasing the miscibility of nanocrystals in various solvents and matrices (ie, the ability to be mixed without separation) makes the nanocrystals a polymer composition so that the nanocrystals do not aggregate together and therefore do not scatter light. Allows distribution throughout the object. Such ligands are described herein as “miscibility enhancing” ligands.

As used herein, the term nanocomposite refers to a matrix material comprising nanocrystals distributed or embedded therein. Suitable matrix materials can be any material known to those skilled in the art, including polymeric materials, organic and inorganic oxides. The nanocomposites of the present invention can be a layer, encapsulant, coating or film as described herein. In embodiments of the invention referring to layers, polymer layers, matrices or nanocomposites, these terms are used interchangeably and the embodiments described with reference to these terms are It should be understood that it is not limited to a type of nanocomposite and includes any matrix material or layer described herein or known in the art.
Downconverting nanocomposites (e.g., as disclosed in U.S. Patent Application No. 7,374,807) emit light that is tuned to absorb light of a specific wavelength and then emit light at a second wavelength. Utilizing the release characteristics of the nanocrystals, thereby enhancing the performance and efficiency of the active source (eg, LED). As discussed above, the use of luminescent nanocrystals in such down-conversion and other filtering or coating applications often results in the nanocrystals being heated to high temperatures, high intensity light (eg LED sources), external gases and moisture. Expose to. Exposure to these conditions can reduce the efficiency of the nanocrystals and thereby shorten the effective product life. In order to solve this problem, the present invention provides a method for hermetically sealing luminescent nanocrystals.

Luminescent Nanocrystalline Phosphors To produce nanocrystalline phosphors, any method known to those skilled in the art can be used, but preferably a controlled inorganic nanomaterial phosphor. A solution phase colloidal method for continuous growth is used. Alivisatos, A.M. P. "Semiconductor clusters, nanocrystals, and quantum dots", Science, 271: 933 (1996), X. Peng, M.M. Schlamp, A.M. Kadavanich, A.M. P. Alivitas, “Epitaxial growth of high luminance CdSe / CdS Core / Shell nanocrystals with photoaccessibility and electronic accessibility”, J. Am. Am. Chem. Soc. 30: 7019-7029 (1997), and C.I. B. Murray, D.M. J. et al. Norris, M.M. G. Bawendi, “Synthesis and charac- terization of nearly monodisperse CdE (E = sulfur, selenium, tellurium), semiconductor nanocrystals”. Am. Chem. Soc. 115: 8706 (1993). The disclosures of these documents are hereby incorporated by reference in their entirety. This manufacturing process technology boosts low cost processability without the need for clean rooms and expensive manufacturing equipment. In these methods, a metal precursor that undergoes thermal decomposition at high temperatures is rapidly injected into a hot solution of organic surfactant molecules. These precursors decompose at high temperatures and react to produce nanocrystalline nuclei. After this initial nucleation phase, the growth phase begins by adding monomer to the growing crystal. The result is independent crystalline nanoparticles in solution with organic surfactant molecules covering the surface.

  Using this method, synthesis occurs as the first nucleation event that takes place over a few seconds, followed by crystal growth at a high temperature for a few minutes. In order to change the nature and progress of the reaction, parameters such as temperature, the type of surfactant present, the precursor material, the ratio of surfactant to monomer, etc. can be varied. The temperature controls the structural stage of the nucleation event, the precursor decomposition rate and the growth rate. Organic surfactant molecules are involved in both solubility and nanocrystal shape control. The ratio of surfactant to monomer, the ratio between surfactants, the ratio between monomers, and the concentration of individual monomers strongly influence the rate of growth.

  In a preferred embodiment, CdSe is used as the nanocrystalline material, in one example as a nanocrystalline material for visible light downconversion. This is because the synthesis of this material is relatively mature. By using generic surface chemistry, nanocrystals that do not contain cadmium can be used instead.

Core / shell luminescent nanocrystals In semiconductor nanocrystals, light-induced emission occurs from the band edge state of the nanocrystals. Band edge emission from luminescent nanocrystals competes with radioactive and non-radiative decay channels resulting from surface electronic states. X. Peng, et al. J. et al. Am. Chem. Soc. 30: 7019-7029 (1997). As a result, the presence of surface defects such as dangling bonds provides non-radiative recombination centers and contributes to a decrease in emission efficiency. One efficient and permanent way to deactivate and remove this surface trap state is to epitaxially grow an inorganic shell material on the surface of the nanocrystal. X. Peng, et al. J. et al. Am. Chem. Soc. 30: 7019-7029 (1997). The shell material has a larger bandgap so as to provide a potential step to localize electrons and holes to the core such that the electron level is type I with respect to the core material. Can choose). As a result, the probability of nonradioactive recombination can be reduced.

  The core-shell structure is obtained by adding an organometallic precursor that includes a shell material to a reaction mixture that includes a core nanocrystal. In this case, growth does not occur following the nucleation event, but the core acts as a nucleus and the shell grows from the surface of the core. The reaction temperature is kept low to promote the addition of shell material monomer to the core surface and prevent independent nucleation of the shell material nanocrystals. A surfactant is present in the reaction mixture to induce controlled growth of the shell material and ensure solubility. A uniform epitaxial growth shell is obtained when there is a low lattice mismatch between these two materials. Furthermore, the shape of the sphere serves to minimize the interfacial strain energy due to the large radius of curvature, thereby preventing the formation of dislocations that can degrade the optical properties of the nanocrystal system.

Exemplary materials for preparing core-shell luminescent nanocrystals include, but are not limited to, Si, Ge, Sn, Se, Te, B, C (including diamond), P, Co, Au, BN, BP, BAs. AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, ZnO, ZnS, ZnSe, ZnTe, CdS , CdSe, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, Br _{3 N 4, Ge 3 N 4} , Al 2 O 3, (Al, Ga, I ) Containing _{2 (S, Se, Te)} 3, Al 2 CO, and 2 or more suitable combination of the material. Exemplary core-shell luminescent nanocrystals used in the practice of the present invention include, but are not limited to, CdSe / ZnS, InP / ZnS, PbSe / PbS, CdSe / CdS, CdTe / CdS, CdTe / Includes ZnS and others.

Hermetically sealed luminescent nanocrystal compositions In one embodiment, the present invention provides a method of hermetically sealing one or more compositions comprising a plurality of luminescent nanocrystals. As shown in the flowchart 120 of FIG. 1E, referring to the schematic illustrations of FIGS. 1A-1D, the method preferably includes providing a first substrate 102 at step 122. In step 124, one or more compositions 104 including a plurality of luminescent nanocrystals 106 are disposed on the first substrate 102. In step 126, the second substrate 108 is placed on the first substrate so as to cover the composition 104 of the luminescent nanocrystal 106, similar to FIG. 1B. In step 128, the first and second substrates are then sealed.

  As discussed throughout, the terms “hermetic”, “hermetic” and “hermetic” refer to gases that pass through the container or penetrate into the composition and / or contact the luminescent nanocrystals (eg, Used to indicate that the composition of luminescent nanocrystals has been prepared in such a manner that the amount of air) or moisture is reduced to a level that does not substantially achieve nanocrystal performance (eg, luminescence). The Thus, a “hermetically sealed composition”, eg, a hermetically sealed composition containing luminescent nanocrystals, allows a certain amount of air (or other gas, liquid or moisture) to penetrate into the composition and emit light. A composition that does not allow contact with the nanocrystal and, as a result, the performance (eg, luminescence) of the nanocrystal is substantially achieved or affected (eg, reduced).

  As used throughout, multiple light-emitting nanocrystals means two or more nanocrystals (ie, 2, 3, 4, 5, 10, 100, 1,000, 1,000,000, etc. nanocrystals). To do. Preferably, the composition comprises luminescent nanocrystals having the same composition, but in other embodiments, the plurality of luminescent nanocrystals can be of different compositions. For example, the luminescent nanocrystals can all emit at the same wavelength, or in further embodiments, the composition can include luminescent nanocrystals that emit at different wavelengths.

  Suitable matrices for use in the compositions of the present invention include polymers as well as organic or inorganic oxides. Suitable polymers for use in the matrix of the present invention include any polymer known to those skilled in the art that can be used for such purposes. In preferred embodiments, the polymer is substantially translucent, transparent, or substantially transparent. Such polymers include, but are not limited to, poly (vinyl butyral): poly (vinyl acetate); epoxy resin; urethane; silicon and, but not limited to, polyphenylmethylsiloxane, polyphenylalkylsiloxane, polydiphenylsiloxane, polydialkyl Silicon derivatives including siloxane, silicon fluoride, vinyl and hydride substituted silicon; acrylic polymers and copolymers formed from monomers including, but not limited to, methyl methacrylate, butyl methacrylate and lauryl methacrylate; styrene-based Polymers; and polymers crosslinked with bifunctional monomers such as divinylbenzene.

  Any suitable method, such as mixing nanocrystals into a polymer and casting a film, mixing nanocrystals with monomers and polymerizing them together, mixing nanocrystals into a sol-gel The luminescent nanocrystals used in the present invention can be converted to polymers (or other suitable materials such as waxes, oils, etc. using methods to form oxides or any other suitable method known to those skilled in the art. ) Can be embedded in the matrix. As used herein, the term “embedding” is used to indicate that a luminescent nanocrystal is surrounded or encapsulated by a polymer that constitutes the major component of the matrix. Preferably, the luminescent nanocrystals are uniformly distributed throughout the matrix, although in other embodiments, the luminescent nanocrystals can be distributed according to an application-specific uniformity distribution function. Should.

  In exemplary embodiments, the first substrate 102 and the second substrate 108 are transparent, substantially transparent, or translucent substrates, such as polymers or glass (eg, silica-containing glass). In an exemplary embodiment, the first and second substrates both comprise glass, while in other embodiments, one of the substrates is glass and the other is a polymeric material or both. Can be a polymeric material. As shown in FIG. 1A, the first substrate 102 is preferably sized such that two or more compositions 104 of luminescent nanocrystals 106 can be disposed thereon. However, in a further embodiment, a single composition 104 comprising a plurality of luminescent nanocrystals 106 can be disposed on a first substrate, and then, if desired, a plurality of first substrates can be Can be used to prepare a plurality of hermetically sealed compositions. The thickness of the first substrate 102 is preferably about 1 μm to about 1 cm, and preferably about 100 μm to about 100 mm. The first and second substrates are preferably the same size, but as long as the composition is sealed by the substrate, in other embodiments they can be sized differently. Preferably, the first and second substrates are approximately a few millimeters to a few meters in at least one lateral dimension (ie in the plane of the substrate). Providing a first substrate 102 that is transparent or translucent allows light to pass through the substrate and contact the luminescent nanocrystals disposed thereon.

  The thickness and size of the composition 104 of the present invention disposed on the first substrate 102 by any method known in the art, such as spin coating, screen printing, dip coating, painting, spraying, etc. (eg : Covering area) can be controlled. The luminescent nanocrystal composition of the present invention can be of any desired size, shape, configuration and thickness. For example, the composition can be disposed on a first substrate that can take the form of layers as well as other shapes, such as disks, drops, spheres, cubes or blocks, tubes, and the like. The various compositions of the present invention can be of any necessary or desired thickness, but preferably the composition thickness (ie one dimension) is from about 1 μm to about 500 μm. Preferably, the composition has at least one dimension in the lateral direction (ie, the plane of the substrate) that ranges from a few microns to a few centimeters. The luminescent nanocrystals can be embedded or distributed in various compositions / matrices at any loading ratio suitable for the desired function. Preferably, the luminescent nanocrystals are loaded at a ratio of about 0.001% to about 75% by volume, depending on the application, matrix and type of nanocrystal used. Suitable loading ratios can be readily determined by those skilled in the art and are further described herein for specific applications. In an exemplary embodiment, the amount of nanocrystals loaded into the luminescent nanocrystal composition is from about 10 volume% to parts per million (ppm) levels.

  Preferably, the size of the luminescent nanocrystal used in the present invention is from less than about 100 nm to less than about 2 nm. In a preferred embodiment, the luminescent nanocrystals of the present invention absorb visible light. As used herein, visible light is electromagnetic radiation having a wavelength from about 380 nanometers to about 780 nanometers visible to the human eye. Visible light can be separated into various colors of the spectrum, such as red, orange, yellow, green, blue, indigo, and purple. The photon filtering nanocomposites of the present invention can be constructed to absorb light comprising any one or more of these colors. For example, the nanocomposites of the present invention can be constructed to absorb blue light, red light or green light, combinations of such colors, or any intermediate color of these colors. As used herein, blue light includes light having a wavelength from about 435 nm to about 500 nm, green light includes light from about 520 nm to 565 nm, and red light from about 625 nm to about 740 nm. Including light. One skilled in the art can construct nanocomposites that can filter these wavelengths or any combination of wavelengths between these colors, and such nanocomposites are embodied by the present invention.

  In other embodiments, the luminescent nanocrystal has a size and composition such that the luminescent nanocrystal absorbs photons in the ultraviolet, near infrared, and / or infrared spectra. As used herein, the ultraviolet spectrum includes light from about 100 nm to about 400 nm, the near infrared spectrum includes light from a wavelength of about 750 nm to about 100 μm, and the infrared spectrum ranges from about 750 nm to about 100 μm. Includes light up to 300 μm.

  In practicing the present invention, luminescent nanocrystals of any suitable material can be used, but in certain embodiments, the nanocrystals can be ZnS, InAs or CdSe nanocrystals, or Nanocrystals can include various combinations to form a population of nanocrystals used in the practice of the present invention. As discussed above, in a further embodiment, the luminescent nanocrystal is a core / shell nanocrystal such as CdSe / ZnS, CdSe / CdS, InP / ZnS.

  As described throughout, the composition 104 of the luminescent nanocrystal 106 preferably comprises a polymer substrate or matrix. For this reason, the present invention provides a method for hermetically sealing a composition containing luminescent nanocrystals, preferably a polymer containing luminescent nanocrystals by sealing the composition between a first and a second substrate. Includes substrate.

  The ability to use a polymer substrate within the composition 104 allows the composition to be formed into various shapes by simply shaping, expanding, dripping, dispersing, spraying, layering, or other processing into the desired shape / orientation. And the composition of the composition. For example, a solution / suspension of luminescent nanocrystals can be prepared (eg, luminescent nanocrystals in a polymer matrix). This solution can then be placed in any desired mold to form the required shape, or simply placed in shape and then cured to form a solid or semi-solid structure. (Eg, cooling or heating depending on the type of polymer). For example, as shown in FIG. 1A, the composition can be arranged in the form of a disc or drop.

  In an exemplary embodiment, the composition 104 comprising the luminescent nanocrystals 106 (Note: the figure is not to scale) may be used, for example, by screen printing, ink jet printing, or any other method that allows multiple individual samples to be volumed onto a substrate. By using applied technology, it is placed on the substrate 102 in a highly productive form.

  In suitable embodiments, the sealing in step 128 of flowchart 120 includes sealing with a polymer sealant. Suitable polymeric sealants that can be used in the practice of the present invention are known and are polymer sealants that are transparent, or at least translucent when dried or cured. Exemplary polymeric sealants that can be used include, but are not limited to, silicone, epoxy, various rubbers, various acrylics, and the like. Preferably, in addition to being transparent or at least translucent, the encapsulant is further impermeable to air and moisture so as to hermetically seal the first and second substrates. Or at least substantially impervious.

  Preferably, the first substrate 102 and the second substrate 108 are encapsulated, dipped, for example, in a sealant 110 such that the sealant forms a seal 112 between the first and second substrates. Sealing is performed by introducing the sealant 110 into the first and second substrates by coating, wicking, painting, injection, or the like. Preferably, the luminescent nanocrystal composition is cured (eg, by heating or cooling) prior to sealing with the sealant.

  In a further embodiment, as shown in FIGS. 2A-2B, the first substrate 102 preferably includes one or more recesses 202 formed in at least one of and on the substrate. As used herein, “recess” refers to a hole, indentation, well, crack, defect, or other indentation in and / or on the substrate 102. Formation of a recess in at least one of the interior and the top means that a recess is formed in and / or on the substrate 102. A recess “on” the first substrate 102 refers to a recess on the surface of the first substrate 102, eg, a recess formed in a third substrate, as described herein. The recess in the “inside” of the first substrate 102 refers to a recess that penetrates the surface of the first substrate 102 at an arbitrary depth. Note that the recesses can be formed both in and on the substrate in the same composition, or can be formed only in or on the substrate 102.

  Preferably, the recess in the substrate 102 does not pass through the entire substrate, but instead has a depth to the substrate that is less than the entire thickness of the substrate, thus providing a reservoir for receiving the composition 104. . Preferably, the recess 202 is about 0.5 mm to about 10 mm in at least one lateral dimension (a dimension in the plane of the first substrate 102, eg, a diameter when a circular shaped recess is utilized); More preferably, in at least one lateral dimension, about 1 mm to about 10 mm, about 1 mm to about 9 mm, about 1 mm to about 8 mm, about 1 mm to about 7 mm, about 1 mm to about 6 mm, about 1 mm to about 5 mm, about 1 mm To about 4 mm, about 1 mm to about 3 mm, about 1 mm to about 2 mm, or about 10 mm, about 9 mm, about 8 mm, about 7 mm, about 6 mm, about 5 mm, about 4 mm, about 3 mm, about 2 mm, or about 1 mm.

  The recesses are preferably sections of the substrate 102 (or other material as described herein) such that they are separated by a distance of about 0.1 mm to about 10 mm (edge-to-edge separation). Separated by. Preferably, the recess 202 is about 1 mm to about 10 mm, about 1 mm to about 9 mm, about 1 mm to about 8 mm, about 1 mm to about 7 mm, about 1 mm to about 6 mm, about 1 mm to about 5 mm, about 1 mm to about 4 mm, Separated at a distance of about 1 mm to about 3 mm, about 1 mm to about 2 mm, or about 10 mm, about 9 mm, about 8 mm, about 7 mm, about 6 mm, about 5 mm, about 4 mm, about 3 mm, about 2 mm, or about 1 mm .

  The depth of the recess 202 to the surface of the substrate 102 (ie, the distance to the substrate that is perpendicular to the surface of the substrate) is determined in part by the thickness of the substrate 102, but the depth is Preferably, only part of the direction toward the surface of the substrate 102 is stretched. In an exemplary embodiment, the depth of the recess 202 is from about 100 μm to about 100 mm, preferably from about 500 μm to about 10 mm. In the exemplary embodiment, the depth of the recess 202 can be uniform in the recess, but in other embodiments, the recess can have a slope or a non-uniform depth.

  In the exemplary embodiment, recess 202 has an annular cross section, but in other embodiments, any shape can be used, such as a rectangle, square, triangle, irregular shape, and the like.

  As shown in a further embodiment in FIG. 2F, the first substrate 102 can further include a third substrate 204 having one or more recesses 202 formed in the third substrate 204. Preferably, the recess in the third substrate passes through the entire surface thickness of the first substrate 102 (in a suitable embodiment, the surface 102 may further have a recess therein). In other embodiments, the recess 202 in the third substrate 204 does not pass through the entire third surface thickness. Thus, as shown in FIG. 2F, the recess 204 can be cylindrical (or other suitable shape, eg, rectangular, square, irregular, etc.). The thickness of the third substrate is preferably about 100 μm to about 100 mm, preferably about 500 μm to about 10 mm, or about 500 μm to about 5 mm.

  In the exemplary embodiment, third substrate 204 includes a polymer material that includes a photoresist material. The use of a photoresist material allows masking or etching to create a recess 202 in the third substrate 204 (as described herein). Examples of methods of utilizing photoresist materials are as well as photoresist developers, for example, the disclosure of that document is incorporated herein by reference in its entirety. M.M. "Semiconductor Devices, Physics and Technology", John Wiley & Sons, New York, pp. 436-442 (1985). In general, a photoresist (such as a negative photoresist) for use in the practice of the present invention comprises a polymer combined with a photosensitive compound. When exposed to radiation (eg, UV light), the photosensitive compound crosslinks with the polymer, thereby providing resistance to the developing solvent. However, the unexposed areas can be removed with a developing solvent. Some exemplary negative photoresist materials and developers are Kodak® 747, copolymer-ethyl acrylate and glycidyl methacrylate (COP), GeSe and poly (glycidyl methacrylate-co-ethyl acrylate) DCOPA including. The placement of the negative photoresist material can be performed using any suitable method, such as spin coating, spray coating, or other material layering. In contrast, a “positive photoresist” material acts oppositely to a negative photoresist material because it is less chemically robust when exposed to radiation. Here, the material exposed to radiation does not change for mask generation, but the areas that do not receive radiation are removed.

  As shown in FIGS. 2B and 2C, the composition 104 comprising luminescent nanocrystals is disposed in the recess 202. Preferably, the recess is filled so that there is no or little gap between the top of the composition 104 and the surface of the substrate 102. This is achieved by providing a tight seal between the second substrate 108 and the first substrate 104 when hermetically sealed with the sealant 110, as shown in FIGS. A hermetically sealed luminescent nanocrystal is provided. Where a third substrate 204 including a recess 202 is utilized, preferably the composition 104 is placed in the recess so that there is no or little gap between the top of the composition and the surface of the third substrate 102. The

  In a further embodiment, as shown in FIG. 1E, the method of the present invention further comprises step 130 in which a barrier layer (not shown) is disposed on the surfaces of the first substrate 102 and the second substrate 108. Can be included. As used herein, the term “barrier layer” is used to indicate a layer, coating, encapsulant, or other material disposed on a first substrate and a second substrate. The Such a barrier layer provides an additional measure of hermetic sealing above and below the hermetic seal provided by the sealing of the first and second substrates.

Examples of barrier layers include any material layer, coating or substance that can create a hermetic seal on the substrate / composition. Suitable barrier layers include inorganic layers, preferably inorganic oxides such as oxides of Al, Ba, Ca, Mg, Ni, Si, Ti, Zr. Exemplary inorganic oxide layer _comprises SiO _2, TiO 2, AlO 2 and the like. As used throughout, the terms “place” and “place” include any suitable method of depositing a barrier layer. For example, the arrangement includes layering, coating, spraying, sputtering, plasma assisted chemical vapor deposition, atomic layer deposition, or other suitable methods of depositing a barrier layer on a substrate / composition. In a preferred embodiment, sputtering is used to place a barrier layer on the substrate / composition. Sputtering includes a physical vapor deposition process in which high energy ions are used to bombard the material element source, the material element source emits atomic vapor, and then the atomic vapor is deposited as a thin layer on the substrate. . See, for example, US Pat. Nos. 6,541,790, 6,107,105, and 5,667,650. The disclosures of each of these documents are each hereby incorporated by reference in their entirety.

  In a further embodiment, barrier layer placement can be performed using atomic layer deposition. In order to properly hermetically seal the nanocrystalline composition, a barrier layer that is virtually defect-free (ie pinhole free) is often necessary. Furthermore, the arrangement of the barrier layer should not degrade the polymer, substrate and / or nanocrystal. Thus, in a preferred embodiment, atomic layer deposition is used to place the barrier layer.

Atomic layer deposition (ALD) can include placing an oxide layer (eg, TiO ₂ , SiO ₂ , AlO _2, etc.) on a substrate / composition, or in further embodiments, nitride (eg, Non-conductive layer deposition (such as silicon nitride) can be used. ALD deposits an atomic layer (i.e., only a few molecules thick) by alternately supplying reactant and purge gases. Thin coatings with high aspect ratios, uniformity within the recesses, and good electrical and physical properties can be formed. Preferably, the barrier layer deposited by the ALD method has a low impurity concentration and a thickness of less than 1000 nm, preferably less than about 500 nm, less than about 200 nm, less than about 50 nm, less than about 20 nm, or less than about 5 nm.

  For example, in a preferred embodiment, two reaction gases, A and B, are used. When only the reaction gas A flows into the reaction chamber, the atoms of the reaction gas A are chemically adsorbed on the substrate / composition. Next, the remaining reaction gas A is purged with an inert gas such as Ar or nitrogen. Next, the reaction gas B flows in, and the chemical reaction between the reaction gases A and B occurs only on the surface where the reaction gas A of the substrate / composition is adsorbed. As a result, the atomic barrier layer is formed on the substrate / composition. Is formed.

In embodiments in which a non-conductive layer such as a nitride layer is disposed, SiH ₂ Cl ₂ and remote plasma assisted NH ₃ are preferably used to dispose the silicon nitride layer. This embodiment can be performed at low temperatures and does not require the use of reactive oxygen species.

  The use of ALD to place the barrier layer on the substrate / composition produces a barrier layer that is virtually pinhole free, regardless of the substrate morphology. By repeating these deposition steps, the thickness of the barrier layer can be increased, whereby the layer thickness of the atomic layer unit can be increased with the number of repetitions. In addition, the barrier layer can be further coated with additional layers (eg, by sputtering, CVD or ALD) to protect the barrier layer or further strengthen the barrier layer.

  Preferably, the ALD process utilized in the practice of the present invention is performed at a temperature of less than about 500 ° C, preferably less than about 400 ° C, less than about 300 ° C, or less than about 200 ° C.

  Exemplary barrier materials include organic materials designed to clearly reduce oxygen and moisture transmission. Examples include filled epoxy resins (such as alumina filled epoxy resins) and liquid crystal polymers.

  As shown in flow chart 120 of FIG. 1E, the method of the present invention is preferably further sealed to one or more of each other after sealing of the substrate layers, as shown in FIGS. Separating the prepared composition. This separation can be done before or after placement of the barrier layer, but preferably the barrier layer, if utilized, is placed after the separation.

  As shown in FIGS. 3A-3C, a hermetically sealed structure 302 comprising a plurality of individually sealed compositions can be separated into substructures 304 or, preferably, each further As such, it can be separated into discrete structures 306 containing a single hermetically sealed composition comprising a plurality of luminescent nanocrystals. Thus, the preparation of a plurality of hermetically sealed compositions can result in separate, isolated compositions.

  Methods for separating hermetically sealed compositions from each other are known in the art such as mechanical cube cutting (eg, with a knife, wedge, saw, blade, or other cutting instrument), laser, water jet, etc. Various known methods are included.

  In a further embodiment, the present invention provides a further method of hermetically sealing a composition of one or more luminescent nanocrystals. As shown in the flowchart 400 of FIG. 4, with reference to FIGS. 2A-2G, in the exemplary embodiment, the method includes a step 402 in which a first substrate 102 is provided. In step 404 of flowchart 400, one or more recesses 202 are created in and / or on the first substrate.

  In step 406 of flowchart 400, one or more compositions 104 comprising a plurality of luminescent nanocrystals 106 are placed in the recesses 204. In step 408, the second substrate 108 is then placed on the first substrate 102 so as to cover the composition 104 of the luminescent nanocrystal 106. In step 410 of flowchart 400, the first and second substrates 112 are then sealed.

  As described in the full scope, preferably the substrates 102 and 108 are transparent or translucent substrates, such as polymer or glass substrates. The size and thickness of the substrates 102 and 108 are described in the full range.

  Step 404 of flowchart 400 includes creating one or more recesses 202 in and / or on the first substrate 102. In the exemplary embodiment, recess 202 is created directly on the surface of first substrate 102. That is, the material is removed from the surface of the first substrate 102 to create the recess 202. Methods for removing material from the first substrate 102 include etching (eg, chemical etching using various acids or other etchants, including those disclosed herein), gouging, cutting, cutting, Including excavation.

  In a further embodiment, the recess 202 can be created on the first substrate 102. In such an embodiment, the third substrate 204 is preferably disposed on the first substrate 102. A recess 202 is then created in the third substrate, for example by etching (eg, chemical etching using various acids), gouging, cutting, cutting, drilling, etc. into the substrate. Preferably, a masking / etching method is used to create a recess in the third substrate. In a further embodiment, the recess 202 can be created by placing a previously prepared third substrate where the recess has already been created. In another further embodiment, a recess can be formed in the surface of the first substrate 102 by placing and arranging the third substrate portion 206 on the first substrate 102, wherein the recess 202 is As shown in FIG. 2G, it is created and formed within the gap / space between the sections.

  Exemplary compositions comprising luminescent nanocrystals (eg, polymer composition / matrix) and suitable nanocrystals are described in their entirety. Preferably, the luminescent nanocrystal is a core-shell luminescent nanocrystal such as CdSe / ZnS, CdSe / CdS and InP / ZnS. Exemplary sizes of nanocrystals are described herein, and preferably the luminescent nanocrystals are about 1-10 nm in size. Methods for placing the composition of luminescent nanocrystals in the recess have been described to the full extent, including screen printing and other methods to produce highly productive deposits.

  As described in the full scope, preferably the second substrate is a transparent or translucent substrate such as a polymer material or glass. By hermetically sealing the composition of luminescent nanocrystals between two glass substrates, the nanocrystals are utilized for a variety of applications such as downconversion in LEDs as described herein. be able to.

  As described in the full scope, the first and second substrates are preferably hermetically sealed with a polymer sealant such as a silicon-based, epoxy-based or acrylic-based sealant. The sealant pours the sealant onto the substrate (and then squeezes the residue by pressurizing the substrate), wicking the substrate into the space between the substrates, the sealant on the substrate Can be introduced 110 into the first and second substrates using any suitable method, such as injecting, dropping a sealant onto the substrate, and other suitable methods. In other embodiments, the first and second sealants are applied by applying the sealant, for example, without painting, spraying, diffusing, or penetrating the sealant between the first and second substrates. It can be placed on the outer edge of the second substrate.

  As shown in FIG. 4, preferably the luminescent nanocrystals are cured in step 412 before encapsulating the first and second substrates in step 414, but in a further embodiment, the substrate is encapsulated. And then the composition of luminescent nanocrystals can be cured.

The method of the present invention can further include step 414 of flowchart 400 that places a barrier layer on the first and second substrates to further hermetically seal the substrate. Methods for disposing barrier layers (eg, atomic layer deposition, sputtering, etc.) are described in full range, as are exemplary barrier layers including inorganic material layers such as layers including SiO ₂ , TiO _2, or AlO _2. The

  As shown in flowchart 400, the method preferably further includes a step 416 in which the hermetically sealed compositions are separated from one another, as shown, for example, in FIGS. Separation can occur before or after the barrier layer is placed. As described herein, the provided methods allow for separate and separate examples of high-productivity luminescent nanocrystals that can be used for various applications such as LEDs, in displays, and the like.

  The present invention further provides hermetically sealed compositions prepared by the various methods described herein. Exemplary compositions, sizes and characteristics of luminescent nanocrystals, and substrates, encapsulants, and other components (eg, barrier layers) of the encapsulated composition are described to the full extent.

In suitable embodiments of the present invention, various methods for producing hermetically sealed luminescent nanocrystal compositions in a vacuum and / or in an inert atmosphere where only N ₂ or other inert gas is present. The steps are executed.

  As discussed herein, in a preferred embodiment, the hermetically sealed luminescent nanocrystal composition of the present invention is used in combination with an LED or other light source. Applications of these encapsulated nanocrystals / LEDs are known to those skilled in the art and include: For example, such encapsulated nanocrystals / LEDs are described in microprojectors (see, eg, US Pat. Nos. 7,180,566 and 6,755,563. The disclosures of these documents are hereby incorporated by reference in their entirety. Mobile phone, personal digital assistant (PDA), personal media player, gaming device, laptop computer, digital versatile disc (DVD) player and other video output devices It can be used in applications such as personal color eyewear, head-up or head-down (and other) displays for automobiles and aircraft. In further embodiments, hermetically sealed nanocrystals can be used in applications such as digital light processor (DLP) projectors.

  In a further embodiment, the hermetically sealed composition disclosed throughout is used to minimize the properties of an optical system known as an etendue (ie, how wide and where the light spreads). be able to. Arrange the composition or container of the claimed invention, stack in layers, or otherwise cover (or partially cover) the LED or other light source, and the luminescent nanocrystal composition or container By controlling the ratio of the total area (eg thickness) to the area of the LED (eg thickness), the amount or range of etendue can be minimized, thereby increasing the amount of light captured and emitted. Preferably, the thickness of the luminescent nanocrystal composition or container is less than about 1/5 of the thickness of the LED layer. For example, the light-emitting nanocrystal composition or container can be less than about 1/6, less than about 1/7, less than about 1/8, less than about 1/9, less than about 1/10, less than about 1/10 of the thickness of the LED layer. Less than 15 or less than about 1/20.

  In another further embodiment, the present invention provides a microsphere 500 as shown in FIG. Preferably, the microspheres of the present invention include a central region 502 and a first layer 504 on the outer surface 506 of the central region 502, the first layer 504 including one or more luminescent nanocrystals 508. . The microsphere 500 further includes a barrier layer 512 on the outer surface 510 of the first layer 504.

  Exemplary microspheres comprising a central region, a first layer, and nanoparticles, and methods for making such microspheres are disclosed in US Pat. No. 7,229,690, which is incorporated herein by reference. The disclosure is incorporated herein by reference in its entirety.

  As disclosed in US Pat. No. 7,229,690, preferably, the central region 502 comprises silica and the first layer 504 comprises an inorganic material such as silica or titanium. Luminescent nanocrystals 508 contained within microspheres are disclosed herein and preferably include core-shell luminescent nanocrystals such as CdSe / ZnS, CdSe / CdS or InP / ZnS nanocrystals. In an exemplary embodiment, the luminescent nanocrystal is about 1-10 nm in size.

As described in detail herein, the addition of a barrier layer to the surface of the composition comprising the luminescent nanocrystals provides a hermetic seal on the composition, thereby providing moisture and / or air. Reduce or eliminate the passage of nanocrystals. Preferably, the barrier layer 512 on the microsphere 500 includes an inorganic material layer SiO ₂ , TiO _2, or AlO ₂ , although other layers described herein and known in the art are also available. is there.

  In exemplary embodiments, the microspheres 500 of the present invention are less than about 500 microns, such as less than about 400 microns, less than about 250 microns, less than about 100 microns, less than about 50 microns, less than about 10 microns, or about 1 It has a diameter of less than a micron (including values between these ranges).

  The present invention further provides a method of forming microspheres, as illustrated in flowchart 600 of FIG. 6, with reference to FIG. In step 602 of flowchart 600, particles 502 comprising a first inorganic material are provided. The particles are then contacted in step 604 with a composition comprising a second inorganic material precursor and one or more light-emitting nanocrystals 508. In step 606, the peripheral region 504 is formed on the outer surface 506 of the particle 502, and the peripheral region includes the second inorganic material and the luminescent nanocrystal 508. Next, at step 608, a barrier layer 512 is disposed on the outer surface 510 of the peripheral region 504.

  As described herein, preferably silica particles are provided, and the particles are in contact with an organic material comprising silica or titanium containing luminescent nanocrystals. As described herein, the luminescent nanocrystal is preferably a core-shell luminescent nanocrystal, such as a CdSe / ZnS, CdSe / CdS or InP / ZnS nanocrystal having a size of about 1-10 nm. Methods for preparing silica particles and peripheral region 504 are described in full scope in US Pat. No. 7,229,690.

_Preferably, the barrier layer comprising SiO 2, TiO _2, or AlO inorganic material layer such as _2, is disposed on the microspheres. As described herein, the barrier layer can be disposed in a variety of ways, including atomic layer deposition and sputtering.

  Exemplary embodiments of the present invention have been presented. The present invention is not limited to these examples. These examples are presented herein for purposes of illustration and not for purposes of limitation. Alternative embodiments will be apparent to those skilled in the art based on the teachings contained herein (including equivalents, extensions, modifications, deflections, etc., of the embodiments described herein). Such alternative embodiments are within the scope and spirit of the present invention.

  All published articles, patents and patent applications mentioned in this specification are to the extent that each individual published article, patent or patent application is specifically and individually indicated to be incorporated by reference, Which is incorporated herein by reference.

As shown in FIGS. 2B and 2C, the composition 104 comprising luminescent nanocrystals is disposed in the recess 202. Preferably, the recess is filled so that there is no or little gap between the top of the composition 104 and the surface of the substrate 102. This is achieved by providing a tight seal between the second substrate 108 and the first substrate 102 when hermetically sealed with the sealant 110, as shown in FIGS. A hermetically sealed luminescent nanocrystal is provided. Where a third substrate 204 including a recess 202 is utilized, preferably the composition 104 is placed in the recess such that there is no or little gap between the top of the composition and the surface of the third substrate 204. The

As shown in FIG. 4, preferably the luminescent nanocrystals are cured in step 412 prior to sealing the first and second substrates in step 410 , but in a further embodiment, the substrate is sealed. And then the composition of luminescent nanocrystals can be cured.

Claims (96)

A method of hermetically sealing one or more compositions comprising a plurality of luminescent nanocrystals, the method comprising:
(A) providing a first substrate;
(B) disposing one or more compositions comprising a plurality of luminescent nanocrystals on the first substrate;
(C) disposing a second substrate on the first substrate so as to cover the composition of luminescent nanocrystals;
(D) sealing the first and second substrates;
Including a method.   The method of claim 1, wherein the providing includes providing a glass substrate.   The method of claim 1, wherein the providing includes providing a first substrate having one or more recesses formed therein.   The method of claim 1, wherein the providing comprises providing a first substrate further comprising a third substrate having one or more recesses formed therein.   The method of claim 1, wherein disposing in (b) comprises disposing a composition comprising a plurality of core-shell luminescent nanocrystals.   6. Arranging in (b) comprises disposing a composition comprising a plurality of core-shell luminescent nanocrystals selected from the group consisting of CdSe / ZnS, CdSe / CdS and InP / ZnS. the method of.   The method of claim 1, wherein disposing in (b) comprises disposing a composition comprising a plurality of luminescent nanocrystals having a size of about 1-10 nm.   The method according to claim 1, wherein the placing in (c) includes placing a glass substrate.   The method according to claim 1, wherein the sealing in (c) includes sealing with a polymer sealant.   The method according to claim 9, wherein the sealing in (d) includes sealing with an epoxy sealant.   The method of claim 1, further comprising curing the luminescent nanocrystal composition prior to sealing in (d).   The method of claim 1, further comprising disposing a barrier layer on the first and second substrates.   The method of claim 12, wherein disposing the barrier layer includes disposing an inorganic material layer. The method of claim 13, wherein disposing the inorganic material layer comprises disposing a layer of SiO ₂ , TiO ₂ , or AlO ₂ .   The method of claim 12, wherein disposing the barrier layer comprises atomic layer deposition.   The method of claim 12, wherein the disposing comprises sputtering the barrier layer over the composition.   The method of claim 1, wherein the placing in (b) comprises screen printing the plurality of luminescent nanocrystals on the first substrate.   The method of claim 1, further comprising separating the one or more hermetically sealed compositions from each other after sealing in (d). A method of hermetically sealing one or more compositions comprising a plurality of luminescent nanocrystals, the method comprising:
(A) providing a first substrate;
(B) generating one or more recesses in at least one of and in the first substrate;
(C) placing one or more compositions comprising a plurality of luminescent nanocrystals in the recess;
(D) disposing a second substrate on the first substrate so as to cover the composition of luminescent nanocrystals;
(E) sealing the first and second substrates;
Including a method.   The method of claim 19, wherein the providing includes providing a glass substrate.   The method of claim 19, wherein the generating includes etching the first substrate to form one or more recesses therein.   The method of claim 19, wherein the generating includes placing a third substrate having one or more recesses formed therein on the first substrate.   The method of claim 19, wherein the generating includes disposing a third substrate on the first substrate and etching one or more recesses in the third substrate. .   21. The generating includes placing a third substrate on the first substrate to form one or more recesses on the surface of the first substrate. the method of.   20. The method of claim 19, wherein the placing in (c) comprises placing a composition comprising a plurality of core-shell luminescent nanocrystals.   The placing in (c) comprises placing a composition comprising a plurality of core-shell luminescent nanocrystals selected from the group consisting of CdSe / ZnS, CdSe / CdS, and InP / ZnS. The method described.   20. The method of claim 19, wherein disposing in (b) comprises disposing a composition comprising a plurality of luminescent nanocrystals having a size of about 1-10 nm.   The method of claim 19, wherein the placing in (d) comprises placing a glass substrate.   20. The method of claim 19, wherein the sealing in (e) includes sealing with a polymer sealant.   30. The method of claim 29, wherein the sealing in (e) comprises sealing with an epoxy sealant.   20. The method of claim 19, further comprising curing the luminescent nanocrystal composition prior to sealing in (e).   The method of claim 19, further comprising disposing a barrier layer on the first and second substrates.   35. The method of claim 32, wherein disposing the barrier layer includes disposing an inorganic material layer. Wherein placing the inorganic material layer _includes placing a SiO 2, TiO _2, or layer of AlO _2, The method of claim 33.   35. The method of claim 32, wherein disposing the barrier layer includes atomic layer deposition.   35. The method of claim 32, wherein disposing the barrier layer comprises sputtering the barrier layer over the composition.   20. The method of claim 19, wherein the placing in (b) includes screen printing the plurality of luminescent nanocrystals in the recess.   20. The method of claim 19, further comprising separating the one or more hermetically sealed compositions from each other after sealing in (e). A hermetically sealed composition comprising a plurality of luminescent nanocrystals,
(A) providing a first substrate;
(B) disposing one or more compositions comprising a plurality of luminescent nanocrystals on the first substrate;
(C) disposing a second substrate on the first substrate so as to cover the composition of luminescent nanocrystals;
(D) sealing the first and second substrates;
A hermetically sealed composition prepared by a method comprising:   40. The hermetically sealed composition of claim 39, wherein the providing comprises providing a glass substrate.   40. The hermetically sealed composition of claim 39, wherein the providing includes providing a first substrate having one or more recesses formed therein.   40. The hermetically sealed composition of claim 39, wherein the providing comprises providing a first substrate further comprising a third substrate having one or more recesses formed therein.   40. The hermetically sealed composition of claim 39, wherein the disposing in (b) comprises disposing a composition comprising a plurality of core-shell luminescent nanocrystals.   44. Arranging in (b) comprises disposing a composition comprising a plurality of core-shell luminescent nanocrystals selected from the group consisting of CdSe / ZnS, CdSe / CdS, and InP / ZnS. A hermetically sealed composition as described.   40. The hermetically sealed composition of claim 39, wherein the disposing in (b) comprises disposing a composition comprising a plurality of luminescent nanocrystals having a size of about 1-10 nm.   40. The hermetically sealed composition of claim 39, wherein disposing in (c) comprises disposing a glass substrate.   40. The hermetically sealed composition of claim 39, wherein the sealing in (d) comprises sealing with a polymer sealant.   48. The hermetically sealed composition of claim 47, wherein the sealing in (d) includes sealing with an epoxy sealant.   40. The hermetically sealed composition of claim 39, further comprising curing the luminescent nanocrystal composition prior to sealing in (d).   40. The hermetically sealed composition of claim 39, further comprising disposing a barrier layer on the first and second substrates.   51. The hermetically sealed composition of claim 50, wherein disposing the barrier layer includes disposing an inorganic material layer. Wherein placing the inorganic material layer includes placing the SiO _2, a layer of TiO ₂ or AlO _2, hermetically sealed composition of claim 51.   51. The hermetically sealed composition of claim 50, wherein disposing the barrier layer comprises atomic layer deposition.   51. The hermetically sealed composition of claim 50, wherein disposing the barrier layer comprises sputtering the barrier layer over the composition.   40. The hermetically sealed composition of claim 39, wherein the disposing in (b) comprises screen printing the plurality of luminescent nanocrystals on the first substrate.   40. The hermetically sealed composition of claim 39, wherein the one or more hermetically sealed compositions are separated from each other after sealing in (d). A hermetically sealed composition comprising a plurality of luminescent nanocrystals,
(A) providing a first substrate;
(B) generating one or more recesses in at least one in and on the first substrate;
(C) placing one or more compositions comprising a plurality of luminescent nanocrystals in the recess;
(D) disposing a second substrate on the first substrate so as to cover the composition of luminescent nanocrystals;
(E) disposing a sealant for sealing the first and second substrates;
A hermetically sealed composition prepared by a method comprising:   58. The hermetically sealed composition of claim 57, wherein the providing includes providing a glass substrate.   58. The hermetically sealed composition of claim 57, wherein the generating comprises etching the first substrate to form one or more recesses therein.   58. The hermetically sealed composition of claim 57, wherein the generating comprises disposing a third substrate having one or more recesses formed therein on the first substrate. .   58. The hermetic seal of claim 57, wherein the generating includes disposing a third substrate on the first substrate and etching one or more recesses in the third substrate. Composition.   58. The generating of claim 57, wherein the generating includes placing a third substrate on the first substrate to form one or more recesses on the surface of the first substrate. A hermetically sealed composition.   58. The hermetically sealed composition of claim 57, wherein the disposing in (c) comprises disposing a composition comprising a plurality of core-shell luminescent nanocrystals.   64. The placing in (c) comprises placing a composition comprising a plurality of core-shell luminescent nanocrystals selected from the group consisting of CdSe / ZnS, CdSe / CdS, and InP / ZnS. A hermetically sealed composition.   58. The hermetically sealed composition of claim 57, wherein the disposing in (b) includes disposing a composition comprising a plurality of luminescent nanocrystals having a size of about 1-10 nm.   58. The hermetically sealed composition according to claim 57, wherein the disposing in (d) includes disposing a glass substrate.   58. The hermetically sealed composition of claim 57, wherein the disposing in (e) comprises disposing a polymer sealant.   68. The hermetically sealed composition of claim 67, wherein the placing in (e) comprises placing an epoxy sealant.   58. The hermetically sealed composition of claim 57, further comprising curing the luminescent nanocrystal composition prior to disposing the sealant in (e).   58. The hermetically sealed composition of claim 57, further comprising disposing a barrier layer on the first and second substrates.   71. The hermetically sealed composition of claim 70, wherein disposing the barrier layer includes disposing an inorganic material layer. Wherein placing the inorganic material layer includes placing the SiO _2, a layer of TiO ₂ or AlO _2, hermetically sealed composition of claim 71.   71. The hermetically sealed composition of claim 70, wherein disposing the barrier layer comprises atomic layer deposition.   71. The hermetically sealed composition of claim 70, wherein disposing the barrier layer comprises sputtering the barrier layer onto the composition.   58. The hermetically sealed composition of claim 57, wherein the placing in (b) comprises screen printing the plurality of luminescent nanocrystals in the recess.   58. The hermetically sealed composition of claim 57, wherein the one or more hermetically sealed compositions are separated from each other after sealing in (e). A microsphere,
(A) a central region;
(B) a first layer on the outer surface of the central region, the first layer comprising one or more luminescent nanocrystals;
(C) a barrier layer on the outer surface of the first layer;
Including, microspheres.   78. The microsphere of claim 77, wherein the central region comprises silica.   78. The microsphere of claim 77, wherein the first layer comprises an inorganic material.   80. The microsphere of claim 79, wherein the inorganic material comprises silica or titanium.   78. The microsphere of claim 77, wherein the luminescent nanocrystal is a core-shell luminescent nanocrystal.   82. The microsphere of claim 81, wherein the core-shell luminescent nanocrystal is selected from the group consisting of CdSe / ZnS, CdSe / CdS, and InP / ZnS.   78. The microsphere of claim 77, wherein the luminescent nanocrystal is about 1-10 nm in size.   78. The microsphere of claim 77, wherein the barrier layer includes an inorganic material layer. The barrier layer _comprises SiO 2, TiO _2, or AlO _2, microsphere of claim 84.   78. The microsphere of claim 77, wherein the microsphere has a diameter of less than about 500 microns.   90. The microsphere of claim 86, wherein the microsphere has a diameter of less than about 10 microns.   90. The microsphere of claim 86, wherein the microsphere has a diameter of less than about 1 micron. A method of forming a microsphere,
(A) providing particles comprising a first inorganic material;
(B) contacting the particles with a composition comprising a precursor of a second inorganic material and one or more luminescent nanocrystals;
(C) forming a peripheral region on the outer surface of the particle, the peripheral region including the second inorganic material and the luminescent nanocrystal;
(D) disposing a barrier layer on the outer surface of the peripheral region;
Including a method.   90. The method of claim 89, wherein the providing comprises providing silica particles.   90. The method of claim 89, wherein the contacting comprises contacting with a composition comprising silica or titanium.   90. The method of claim 89, wherein the contacting comprises contacting with a composition comprising core-shell luminescent nanocrystals.   94. The method of claim 92, wherein the contacting comprises contacting with a composition comprising a luminescent nanocrystal selected from the group consisting of CdSe / ZnS, CdSe / CdS, and InP / ZnS.   90. The method of claim 89, wherein the contacting comprises contacting with a composition comprising luminescent nanocrystals having a size of about 1-10 nm.   90. The method of claim 89, wherein disposing the barrier layer comprises disposing an inorganic material layer. Placing the barrier layer _comprises placing SiO 2, TiO _2, or AlO _2, The method of claim 95.

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