55results about How to "Suppresses light absorption" patented technology

A semiconductor device having a light-emitting element with excellent light-emitting characteristics is provided. The semiconductor device is provided with a first depressed portion or opening portion formed in an insulating film; a first electrode which is formed over the insulating film around the first depressed portion or opening portion, which is positioned in the first depressed portion or opening portion, and which forms a second depressed portion together with the first depressed portion or opening portion; a semiconductor layer of a first conductivity type which is formed over the first electrode and which forms a third depressed portion together with the second depressed portion; a light-emitting layer which is formed over the semiconductor layer of the first conductivity type and which forms a fourth depressed portion together with the third depressed portion; a semiconductor layer of a second conductivity type which is formed over the light-emitting layer and which forms a fifth depressed portion together with the fourth depressed portion; and a second electrode formed over the semiconductor layer of the second conductivity type that forms a bottom surface and a side surface of the fifth depressed portion.

In an optical waveguide device according to the present invention, a multi-layer cladding which is formed by laminating one or more high refractive index layers having the refractive index higher than that of a core and one or more low refractive index layers having the refractive index lower than that of the core, is disposed on a substrate on which an optical waveguide is formed, and utilizing the structural birefringence of this multi-layer cladding, the polarization-dependence of the optical waveguide is increased. As a result, it becomes possible to provide the optical waveguide device having a simple optical waveguide structure for selectively attenuating one of polarization modes of a propagated light.

An object of the present invention is to provide a Group III nitride semiconductor element which comprises a thick AlGaN layer exhibiting high crystallinity and containing no cracks, and which does not include a thick GaN layer (which generally serves as a light-absorbing layer in an ultraviolet LED).The inventive Group III nitride semiconductor element comprises a substrate; a first nitride semiconductor layer composed of AlN which is provided on the substrate; a second nitride semiconductor layer composed of Alx1Ga1-x1N (0≦x1≦0.1) which is provided on the first nitride semiconductor layer; and a third nitride semiconductor layer composed of Alx2Ga1-x2N (0<x2<1 and x1+0.02≦x2) which is provided on the second nitride semiconductor layer.

This optical modulator includes a substrate and a phase modulation unit on the substrate, said phase modulation unit including: a first traveling-wave electrode, a second traveling-wave electrode, and an optical waveguide configured from a first cladding layer, a semiconductor layer, which is laminated on the first cladding layer, and has a refractive index that is higher than that of the first cladding layer, and a second cladding layer, which is laminated on the semiconductor layer, and has a refractive index that is lower than that of the semiconductor layer. The semiconductor layer is provided with: a rib section, which is formed in the optical axis direction of the optical waveguide, and is to be the core of the optical waveguide; a first slab section formed in the optical axis direction on one side of the rib section; a second slab section formed in the optical axis direction on the other side of the rib section; a third slab section formed in the optical axis direction on the first slab section side opposite to the rib section; and a fourth slab section formed in the optical axis direction on the second slab section side opposite to the rib section. The first slab section is formed thinner than the rib section and the third slab section, and the second slab section is formed thinner than the rib section and the fourth slab section.

A light-emitting device includes a substrate; a light-emitting element mounted on the substrate; a first light-transmissive member bonded to an upper surface of the light-emitting element via an adhesive; and a second light-transmissive member placed on an upper surface of the first light-transmissive member. In a plan view of the light-emitting device, a peripheral edge of a lower surface of the first light-transmissive member is positioned more inward than a peripheral edge of the upper surface of the light-emitting element. The adhesive extends from the upper surface of the light-emitting element to a lower surface of the second light-transmissive member, the adhesive covers a side surface of the first light-transmissive member, and the adhesive is separated from the substrate.

The invention relates to an organic electroluminescence element. The present invention provides an organic EL element having a multi-photon structure, in which optical absorption in the visible region caused by a charge-transfer complex in a conventional intermediate layer structure is inhibited, and the resistance of this intermediate layer to a counter career is improved, thus allowing high efficiency and a long operation life of the element. The element is arranged to be formed on a substrate 1 and have a multi-photon structure in which a plurality of light emitting units 4 including at least one light emitting layer are stacked via an intermediate layer 5 between an anode layer 2 and a cathode layer 3 which is a counter electrode, the above-mentioned intermediate layer 5 is formed by mixing or stacking an electron accepting material or an electron donating material and an organic compound, so as to avoid formation of a charge-transfer complex.

Disclosed is a light-emitting device (100) has a light-emitting layer portion (24) which is composed of a group III-V compound semiconductor and a transparent thick-film semiconductor layer (90) with a thickness of not less than 40 μm which is formed on at least one major surface side of the light-emitting layer portion (24) and composed of a group III-V compound semiconductor having a band gap energy larger than the photon energy equivalent of the peak wavelength of emission flux from the light-emitting layer portion (24). The transparent thick-film semiconductor layer (90) has a lateral surface portion (90S) which is a chemically etched surface. The dopant concentration of the transparent thick-film semiconductor layer (90) is not less than 5×1016 / cm3 and not more than 2×1018 / cm3. The light-emitting device can have a transparent thick-film semiconductor layer while being significantly improved in light taking-out efficiency from the lateral surface portion.

A surface emitting laser having a photonic crystal layer 130 on a substrate 105 with an active layer therebetween, in which the photonic crystal layer includes at least a first periodic structure for resonating in an in-plane direction and a second periodic structure for modulating a light intensity distribution in an in-plane direction. The light intensity in the photonic crystal layer is periodically distributed to a region having high light intensity and a region having low light intensity by the second periodic structure. Further, a conductive film 170 for performing current injection into the active layer is selectively provided just above the region having low light intensity. The surface emitting laser provides suppression of light absorption and highly efficient current injection into an active layer to attain a high power.

A method of manufacturing a semiconductor light-emitting device includes steps of forming a vertical cavity structure including a layer to be oxidized on a semiconductor substrate, and then forming a circular groove having a depth which penetrates at least the layer to be oxidized from an upper surface of the vertical cavity structure, thereby forming a columnar mesa whose side face is surrounded by the groove, oxidizing the layer to be oxidized from the side face of the mesa, thereby forming a current confinement layer, and forming a mask layer covering at least a central region of the upper surface of the mesa and exposing at least an edge of the upper surface and the side face of the mesa to an external, and then etching at least the edge of the upper surface and the side face of the mesa by using the mask layer as a mask.

An oligoaniline compound represented by the formula (1) can provide a charge transporting thin film which shows a suppressed coloration in the visible range. Use of this thin film makes it possible to ensure a color reproducibility of a device without lowering the color purity of an electroluminescent light or a light having passed through a color filter.wherein R1 to R10 independently represent each a hydrogen atom, a halogen, etc.; m and n independently represent each an integer of 1 or more while satisfying the condition m+n≦20; and X is a structure represented by any of the following formulae (4) to (10), etc.;wherein R21 to R36 independently represent each a hydrogen atom, a hydroxyl group, etc.; p and q represent each an integer of 1 or more while satisfying the conditions p≦20 and q≦20; and W1s independently represent each —(CR1R2)p-, —O—, —S—, etc.

In a top emission type organic EL display device, brightness gradient in a screen is reduced while keeping a screen brightness. A reflection film is formed under a lower electrode and the light from an organic EL layer is emitted through an upper electrode. Light absorption of the upper electrode is larger on the side of a shorter wavelength. When a film thickness of the upper electrode is enlarged in order to reduce the brightness gradient in a screen, the film thicknesses of the upper electrodes for a red pixel and a green pixel are enlarged without enlarging the film thickness of the upper electrode for a blue pixel. This makes it possible to reduce the brightness gradient as well as to suppress the light absorption of the upper electrode.