# US 8,541,778 B2 · Diffraction grating, organic EL element using the same, and manufacturing methods thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,778 B2 - Document ID: US8541778B2 - Status: Granted - Kind: B2 - Application number: 13/384,551 - Filed: 2010-07-16 - Published: 2012-05-31 - Granted: 2013-09-24 - Earliest claimed: 2009-07-16 - Assignees: Jx Nippon Oil & Energy Corporation - Applicants: Takashi Seki; Suzushi Nishimura; Maki Fukuda; Madoka Fukushima; Satoshi Masuyama; Soon Moon Jeong; Hideo Takezoe; Won Hoe Koo - Inventors: Takashi Seki; Suzushi Nishimura; Maki Fukuda; Madoka Fukushima; Satoshi Masuyama; Soon Moon Jeong; Hideo Takezoe; Won Hoe Koo - Web page: https://patentgrep.com/patent/US8541778B2 ## CPC - G02B 5/1809: {with pitch less than or comparable to the wavelength} - H05B 33/10: Apparatus or processes specially adapted to the manufacture of electroluminescent light sources - H10K 50/858: comprising refractive means, e.g. lenses - H10K 71/821: {Patterning of a layer by embossing, e.g. stamping to form trenches in an insulating layer} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract A diffraction grating having a transparent supporting substrate; and a cured resin layer which is stacked on the transparent supporting substrate and which has concavities and convexities formed on a surface thereof, wherein when a Fourier-transformed image is obtained by performing two-dimensional fast Fourier transform processing on a concavity and convexity analysis image obtained by analyzing a shape of the concavities and convexities formed on the surface of the cured resin layer by use of an atomic force microscope, the Fourier-transformed image shows a circular or annular pattern substantially centered at an origin at which an absolute value of wavenumber is 0 μm−1, and the circular or annular pattern is present within a region where an absolute value of wavenumber is within a range of 10 μm−1 or less. ## Claims ### Claim 1 A diffraction grating comprising: a transparent supporting substrate; and a cured resin layer which is stacked on the transparent supporting substrate and which has concavities and convexities formed on a surface thereof, wherein when a Fourier-transformed image is obtained by performing two-dimensional fast Fourier transform processing on a concavity and convexity analysis image obtained by analyzing a shape of the concavities and convexities formed on the surface of the cured resin layer by use of an atomic force microscope, the Fourier-transformed image shows a circular or annular pattern substantially centered at an origin at which an absolute value of wavenumber is 0 μm−1, and the circular or annular pattern is present within a region where an absolute value of wavenumber is within a range of 10 μm−1 or less. ### Claim 2 (depends on 1) The diffraction grating according to claim 1, wherein the pattern is an annular pattern, and the annular pattern is present within a region where the absolute value of wavenumber is within a range from 1.25 to 5 μm−1. ### Claim 3 (depends on 1) The diffraction grating according to claim 1, wherein an average height of the concavities and convexities formed on the surface of the cured resin layer is within a range from 20 to 200 nm. ### Claim 4 (depends on 1) The diffraction grating according to claim 1, wherein an average pitch of the concavities and convexities formed on the surface of the cured resin layer is within a range from 100 to 600 nm. ### Claim 5 (depends on 1) The diffraction grating according to claim 1, wherein an average value and a median of a depth distribution of the concavities and convexities formed on the surface of the cured resin layer satisfy a condition represented by the following inequality (1): 0.95×Y≦M≦1.05×Y (1) wherein in the inequality (1), Y represents a value obtained by calculation according to a formula: Y=1.062 m−2.2533 (in the formula, m represents the average value of the depth distribution of the concavities and convexities), and M represents the median of the depth distribution of the concavities and convexities. ### Claim 6 (depends on 1) The diffraction grating according to claim 1, wherein a kurtosis of the concavities and convexities formed on the surface of the cured resin layer has a value of −1.2 or greater. ### Claim 7 (depends on 1) The diffraction grating according to claim 1, wherein a kurtosis of the concavities and convexities formed on the surface of the cured resin layer has a value within a range from −1.2 to 1.2. ### Claim 8 A method for manufacturing a diffraction grating, comprising: a step of applying a curable resin onto a transparent supporting substrate, then curing the curable resin with a master block being pressed thereto, and thereafter detaching the master block, thereby stacking, on the transparent supporting substrate, a cured resin layer having concavities and convexities formed thereon, wherein the master block is obtained by any of the following methods (A) and (B) for manufacturing a master block: (A) the method (A) for manufacturing a master block comprising the steps of: applying a block copolymer solution comprising a block copolymer and a solvent onto a base member, the block copolymer having a first polymer segment made of a first homopolymer and a second polymer segment made of a second homopolymer having a solubility parameter which is higher than a solubility parameter of the first homopolymer by 0.1 to 10 (cal/cm3)1/2, and satisfying all the following conditions (i) to (iii): (i) a number average molecular weight is 500000 or more, (ii) a molecular weight distribution (Mw/Mn) is 1.5 or less, and (iii) a volume ratio between the first polymer segment and the second polymer segment (the first polymer segment:the second polymer segment) is 3:7 to 7:3; and forming a micro phase separation structure of the block copolymer by drying a coating film on the base member, thereby obtaining a first master block having concavities and convexities formed on a surface thereof; and (B) the method (B) for manufacturing a master block comprising the steps of: a method comprising the steps of: forming a vapor-deposition film under a temperature condition of 70° C. or above on a surface of a polymer film made of a polymer whose volume changes by heat, and then cooling the polymer film and the vapor-deposition film, thereby forming concavities and convexities of wrinkles on a surface of the vapor-deposition film; and attaching a master block material onto the vapor-deposition film, then curing the master block material, and thereafter detaching the cured master block material from the vapor-deposition film, thereby obtaining a master block. ### Claim 9 (depends on 8) The method for manufacturing a diffraction grating according to claim 8, wherein in the step of obtaining the first master block in the method (A) for manufacturing a master block, the dried coating film is heated at a temperature higher than a glass transition temperature of the block copolymer. ### Claim 10 (depends on 8) The method for manufacturing a diffraction grating according to claim 8, wherein in the step of obtaining the first master block in the method (A) for manufacturing a master block, the dried coating film is subjected to an etching treatment. ### Claim 11 (depends on 8) The method for manufacturing a diffraction grating according to claim 8, wherein the method (A) for manufacturing a master block further comprises a step of attaching a transfer material onto the first master block, then curing the transfer material, and thereafter detaching the transfer material from the first master block, thereby obtaining a second master block having concavities and convexities formed on a surface thereof. ### Claim 12 (depends on 8) The method for manufacturing a diffraction grating according to claim 8, wherein a combination of the first homopolymer and the second homopolymer in the block copolymer used in the method (A) for manufacturing a master block is any of a combination of a styrene-based polymer and a polyalkyl methacrylate, a combination of a styrene-based polymer and polyethylene oxide, a combination of a styrene-based polymer and polyisoprene, and a combination of a styrene-based polymer and polybutadiene. ### Claim 13 (depends on 8) The method for manufacturing a diffraction grating according to claim 8, wherein the block copolymer solution used in the method (A) for manufacturing a master block further comprises a different homopolymer from the first homopolymer and the second homopolymer in the block copolymer. ### Claim 14 (depends on 13) The method for manufacturing a diffraction grating according to claim 13, wherein a combination of the first homopolymer and the second homopolymer in the block copolymer is a combination of polystyrene and polymethyl methacrylate, and the different homopolymer is a polyalkylene oxide. ### Claim 15 (depends on 8) The method for manufacturing a diffraction grating according to claim 8, wherein the polymer whose volume changes by heat used in the method (B) for manufacturing a master block is a silicone-based polymer. ### Claim 16 (depends on 8) The method for manufacturing a diffraction grating according to claim 8, wherein an average pitch of the concavities and convexities formed on the surface of the cured resin layer is within a range from 100 to 600 nm. ### Claim 17 (depends on 1) An organic EL element comprising: a transparent supporting substrate; a cured resin layer which is stacked on the transparent supporting substrate and which has concavities and convexities formed on a surface thereof; and a transparent electrode, an organic layer, and a metal electrode, which are stacked in this order on the cured resin layer and formed into such shapes that a shape of the concavities and convexities formed on the surface of the cured resin layer is maintained, wherein a constituent portion formed by the transparent supporting substrate and the cured resin layer in the organic EL element comprises the diffraction grating according to claim 1. ### Claim 18 (depends on 8) A method for manufacturing an organic EL element, the organic EL element comprising a transparent supporting substrate, a transparent electrode, an organic layer, and a metal electrode, the method comprising: a diffraction grating formation step comprising a step of applying a curable resin onto a transparent supporting substrate, then curing the curable resin with a master block being pressed thereto, and thereafter detaching the master block, thereby stacking, on the transparent supporting substrate, a cured resin layer having concavities and convexities formed thereon; and a step of stacking, on the cured resin layer, each of the transparent electrode, the organic layer, and the metal electrode formed into such a shape that a shape of the concavities and convexities formed on the surface of the cured resin layer is maintained, thereby obtaining an organic EL element, wherein the diffraction grating formation step is the method for manufacturing a diffraction grating according to claim 8.