Abstract: Provide is a light emitting device including a reflective layer including a phase modulation surface, a planarization layer disposed on the reflective layer, a first electrode disposed on the planarization layer, an organic emission layer disposed on the first electrode and configured to emit visible light that includes light of a first wavelength and light of a second wavelength that is shorter than the first wavelength, and a second electrode disposed on the organic emission layer, wherein the reflective layer and the second electrode form a micro cavity configured to resonate the light of the first wavelength, and wherein the planarization layer includes a light absorber configured to absorb the light of the second wavelength.

Abstract: Provide is a light emitting device including a reflective layer including a phase modulation surface, a planarization layer disposed on the reflective layer, a first electrode disposed on the planarization layer, an organic emission layer disposed on the first electrode and configured to emit visible light that includes light of a first wavelength and light of a second wavelength that is shorter than the first wavelength, and a second electrode disposed on the organic emission layer, wherein the reflective layer and the second electrode form a micro cavity configured to resonate the light of the first wavelength, and wherein the planarization layer includes a light absorber configured to absorb the light of the second wavelength.

Abstract: Provide is a light emitting device including a reflective layer including a phase modulation surface, a planarization layer disposed on the reflective layer, a first electrode disposed on the planarization layer, an organic emission layer disposed on the first electrode and configured to emit visible light that includes light of a first wavelength and light of a second wavelength that is shorter than the first wavelength, and a second electrode disposed on the organic emission layer, wherein the reflective layer and the second electrode form a micro cavity configured to resonate the light of the first wavelength, and wherein the planarization layer includes a light absorber configured to absorb the light of the second wavelength.

Abstract: A polyimide that is a reaction product of a diamine represented by Chemical Formula 1, a diamine represented by Chemical Formula 2, and a tetracarboxylic dianhydride represented by Chemical Formula 3: wherein, in Chemical Formulae 1 to 3, L1, L2, Ra to Rf, m, R2, R10, R12, R13, n7, and n8 are the same as defined in the specification.

Abstract: A diffractive optical element including a diffraction layer including a plurality of optical axes along an in-plane direction, wherein the diffraction layer includes an anisotropic material that satisfies one of Relationship Equations 1A to 3A ?n1(450 nm)<?n1(550 nm)??n1(650 nm)??Relationship Equation 1A ?n1(450 nm)??n1(550 nm)<?n1(650 nm)??Relationship Equation 2A ?n1(450 nm)=?n1(550 nm)=?n1(650 nm)??Relationship Equation 3A wherein, in Relationship Equations 1A to 3A, ?n1 (450 nm) is a birefringence of the anisotropic material at a wavelength of 450 nanometers, ?n1 (550 nm) is a birefringence of the anisotropic material at a wavelength of 550 nanometers, and ?n1 (650 nm) is a birefringence of the anisotropic material at a wavelength of 650 nanometers.

Abstract: A light emitting device includes a first electrode; a white organic light emission structure provided on the first electrode; a second electrode provided on the white organic light emission structure; and a reflective layer provided on an opposite side of the first electrode from the white organic light emission structure and including a first reflective region, a second reflective region, and a third reflective region having different heights from one another and forming different separation distances from the second electrode. A plurality of recesses may be provided in at least one of the first reflective region, the second reflective region, and the third reflective region on a surface of the reflective layer, and thus the color purity of the light emitting device may be improved.

Abstract: Provide is a light emitting device including a reflective layer including a phase modulation surface, a planarization layer disposed on the reflective layer, a first electrode disposed on the planarization layer, an organic emission layer disposed on the first electrode and configured to emit visible light that includes light of a first wavelength and light of a second wavelength that is shorter than the first wavelength, and a second electrode disposed on the organic emission layer, wherein the reflective layer and the second electrode form a micro cavity configured to resonate the light of the first wavelength, and wherein the planarization layer includes a light absorber configured to absorb the light of the second wavelength.

Abstract: A diffractive optical element including a diffraction layer including a plurality of optical axes along an in-plane direction, wherein the diffraction layer includes an anisotropic material that satisfies one of Relationship Equations 1A to 3A ?n1(450 nm)<?n1(550 nm)??n1(650 nm)??Relationship Equation 1A ?n1(450 nm)??n1(550 nm)<?n1(650 nm)??Relationship Equation 2A ?n1(450 nm)=?n1(550 nm)=?n1(650 nm)??Relationship Equation 3A wherein, in Relationship Equations 1A to 3A, ?n1 (450 nm) is a birefringence of the anisotropic material at a wavelength of 450 nanometers, ?n1 (550 nm) is a birefringence of the anisotropic material at a wavelength of 550 nanometers, and ?n1 (650 nm) is a birefringence of the anisotropic material at a wavelength of 650 nanometers.

Abstract: A polyimide that is a reaction product of a diamine represented by Chemical Formula 1, a diamine represented by Chemical Formula 2, and a tetracarboxylic dianhydride represented by Chemical Formula 3: wherein, in Chemical Formulae 1 to 3, L1, L2, Ra to Rf, m, R2, R10, R12, R13, n7, and n8 are the same as defined in the specification.

Abstract: A polyimide film, which is a reaction product of a diamine including an amide structural unit in an amount of greater than about 0 mol % and less than or equal to about 80 mol % and an aromatic dianhydride, wherein the polyimide film has a Martens hardness of about 14 N/mm2 to about 120 N/mm2 at a thickness of about 30 ?m to about 100 ?m.