1832results about How to "Improve luminous efficiency" patented technology

A package structure including a first lead, a second lead, an encapsulant, a light-emitting device and an electrostatic discharge (ESD) protection device is provided. The second lead is disposed beside the first lead, and parts of the first lead and the second lead are encapsulated by the encapsulant. The encapsulant has a first cavity and a second cavity. Parts of the first lead and the second lead are exposed by the first cavity and the other parts of the first lead and the second lead are exposed by the second cavity. The light-emitting device is disposed inside the first cavity and electrically connected to the first lead and the second lead. The ESD protection device is disposed inside the second cavity and electrically connected to the first lead and the second lead.

An OLED device comprises a cathode, an anode, and has therebetween a light-emitting layer containing a phosphorescent emitter and a host comprising a first aluminum or gallium complex containing at least one 2-(2-hydroxyphenyl)pyridine ligand and at least one phenoxy ligand, wherein the phenoxy ligand is substituted by an amine or there is further present adjacent to the light-emitting layer on the cathode side a layer containing a second aluminum or gallium complex containing at least one 2-(2-hydroxyphenyl)pyridine ligand and at least one phenoxy ligand.

Provided is an organic electroluminescent device (organic EL device) that is improved in luminous efficiency, fully secured of driving stability, and simply constructed. The EL device has a light-emitting layer disposed between an anode and a cathode stacked one upon another on a substrate and the light-emitting layer comprises a phosphorescent dopant and an indolocarbazole derivative as a host material. Examples of the indolocarbazole compounds include a compound represented by the following formula (2) or (3), wherein X is N or CH, at least one of Xs is N, and Ar₁ to Ar₃ each is a substituted or unsubstituted aromatic group.

A light-emitting element containing a light-emitting material with high light emission efficiency is provided. The light-emitting element includes a high molecular material and a guest material. The high molecular material includes at least a first high molecular chain and a second high molecular chain. The guest material has a function of exhibiting fluorescence or converting triplet excitation energy into light emission. The first high molecular chain and the second high molecular chain each include a first skeleton, a second skeleton, and a third skeleton, and the first skeleton and the second skeleton are bonded to each other through the third skeleton. The first high molecular chain and the second high molecular chain have a function of forming an excited complex.

Improved apparatus and methods for spatial light modulation are disclosed which utilize optical cavities having both front and rear reflective surfaces. Light-transmissive regions are formed in the front reflective surface for spatially modulating light.

The present invention provides a high quality thin film comparable to a bulk single crystal and providres a semiconductor device with superior characteristics. A channel layer 11, for example, is formed of a semiconductor such as zinc oxide ZnO or the like. A source 12, a drain 13, a gate 14 and a gate insulating layer 15 are formed on the channel layer 111 to form an FET. For a substrate 16, a proper material is selected depending on a thin film material of the channel layer 11 in consideration of compatibility of both lattice constants. For example, if ZnO is used for the semiconductor of the channel layer as a base material, ScAlMgO₄ or the like can be used for the substrate 16.

The light-emitting diode lamp has a light-emitting diode chip mounted on a cup-shaped mounting portion of a lead frame. The mounting portion is formed at one end of a lead portion of the lead frame. The light-emitting diode chip and the mounting portion are embedded in a convex shape lens made of a resin. The lead frame has a hood portion serving as a reflector. The hood portion downwardly reflects the outgoing beam of the light-emitting diode chip and also shields external incident light obliquely from the upper side. Thus, it is possible to increase the luminous efficiency in the downward direction, improve the visibility from the lower side and increase the luminous efficiency in the desired direction without any combination of complicated lens configurations.

A multicolor light-emitting element using fluorescence and phosphorescence, which has a small number of manufacturing steps owing to a relatively small number of layers to be formed and is advantageous for practical application can be provided. In addition, a multicolor light-emitting element using fluorescence and phosphorescence, which has favorable emission efficiency is provided. A light-emitting element which includes a light-emitting layer having a stacked-layer structure of a first light-emitting layer exhibiting light emission from a first exciplex and a second light-emitting layer exhibiting phosphorescence is provided.

Disclosed herein is a nitride semiconductor light emitting device having patterns formed on the upper and lower surfaces of a substrate from which light is emitted in a flip chip bonding structure wherein the patterns are capable of changing light inclination at the upper and lower surfaces of the substrate to decrease total reflection at the interfaces, thereby improving light emitting efficiency. The nitride semiconductor light emitting device comprises a substrate having upper and lower surfaces on which predetermined patterns are formed such that light can be incident within a critical angle, the substrate allowing a gallium nitride-based semiconductor material to be grown thereon, an n-type nitride semiconductor layer formed on the upper surface of the substrate, an active layer formed on the upper surface of the n-type nitride semiconductor layer such that the n-type nitride semiconductor layer is partially exposed, a p-type nitride semiconductor layer formed on the upper surface of the active layer, a p-electrode formed on the upper surface of the p-type nitride semiconductor layer, and an n-side electrode formed on the partially exposed n-type nitride semiconductor layer.

A semiconductor device includes a substrate comprising a first surface having a first orientation and a second surface having a second orientation and a plurality of III-V nitride layers on the substrate, wherein the plurality of III-V nitride layers are configured to emit light when an electric current is produced in one or more of the plurality of III-V nitride layers.

A flip-chip LED including a light emitting structure, a first dielectric layer, a first metal layer, a second metal layer, and a second dielectric layer is provided. The light emitting structure includes a first conductive layer, an active layer, and a second conductive layer. The active layer is disposed on the first conductive layer, and the second conductive layer is disposed on the active layer. The first metal layer is disposed on the light emitting structure and is contact with the first conductive layer, and part of the first metal layer is disposed on the first dielectric layer. The second metal layer is disposed on the light emitting structure and is in contact with the second conductive layer, and part of the second metal layer is disposed on the first dielectric layer. The second dielectric layer is disposed on the first dielectric layer.

The invention provides an oxynitride phosphor represented by a composition formula M_1-aCe_aSi_bAl_cO_dN_e, wherein M denotes La or a compound of which main component is La and sub-component is at least one kind of element selected from the group consisting of Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb and Lu; the a that represents a composition ratio of Ce is a real number satisfying 0.1≦a≦1; the b that represents a composition ratio of Si is a real number satisfying b=(6−z)×f; the c that represents a composition ratio of Al is a real number satisfying c=(1+z)×g; the d that represents a composition ratio of O is a real number satisfying d=z×h; the e that represents a composition ratio of N is a real number satisfying e=(10−z)×i; the z is a real number satisfying 0.1≦z≦3; the f is a real number satisfying 0.7≦f≦1.3; the g is a real number satisfying 0.7≦g≦3; the h is a real number satisfying 0.7≦h≦3; the i is a real number satisfying 0.7≦i≦1.3; and a JEM phase is contained in an amount of 50% or more, and a semiconductor light-emitting device that uses the oxynitride phosphor.

A light-emitting element using GaN. On a substrate (10), formed are an SiN buffer layer (12), a GaN buffer layer (14), an undoped GaN layer (16), an Si-doped n-GaN layer (18), an SLS layer (20), an undoped GaN layer (22), an MQW light-emitting layer (24), an SLS layer (26), and a p-GaN layer (28), forming a p electrode (30) and an n electrode (32). The MQW light-emitting layer (24) has a structure in which InGaN well layers and AlGaN barrier layers are alternated. The Al content ratios of the SLS layers (20, and 26) are more than 5% and less than 24%. The In content ratio of the well layer in the MQW light-emitting layer (24) is more than 3% and less than 20%. The Al content ratio of the barrier layer is more than 1% and less than 30%. By adjusting the content ratio and film thickness of each layer to a desired value, the light luminous efficiency for wavelength of less than 400 nm is improved.

The invention provides an organic electroluminescent device and a display device. The organic electroluminescent device comprises an organic luminescent layer; the organic luminescent layer comprisesa main body material, a sensitizing agent material and a resonance thermally activated delayed fluorescence (TADF) material; the main body material is a broad-band gap material; the sensitizing agentmaterial is a thermally activated delayed fluorescence material; a singlet-state energy level of the thermally activated delayed fluorescence material is located between a singlet-state energy level of the broad-band gap material and a singlet-state energy level of the resonance thermally activated delayed fluorescence material; and a triplet-state energy level of the thermally activated delayed fluorescence material is located between a triplet-state energy level of the broad-band gap material and a triplet-state energy level of the resonance thermally activated delayed fluorescence material.With the organic electroluminescent device and the display device, the defects of short life time and wide spectrum of the device caused by a condition that the traditional TADF material is adopted to emit light at the present stage can be overcome.

A photoluminescent liquid crystal display (PL-LCD) includes: a front plate and a rear plate; liquid crystals disposed between the front and rear plates; an electrode that is disposed on an inner surface of each of the front and rear plates and forms an electric field in the liquid crystals; an emitting layer that is formed on the front plate and emits visible light by being excited by light having a wavelength of about 390 nm to about 410 nm; a light source unit that is formed on a rear side of the rear plate and includes a lamp emitting near blue-UV light having a wavelength of about 390 nm to about 410 nm toward the emitting layer; and a UV filter blocking UV rays in ambient light from entering a front side of the front plate.

A light emitting diode package. A package substrate has first and second electrode structures and a light emitting diode is mounted on the package substrate and electrically connected to the first and second electrode structures. A resin encapsulant is made of a transparent resin to seal the light emitting diode. A plurality of transparent spherical particles having a refractive index higher than the transparent resin are dispersed in the resin encapsulant.

The present invention provides a highly stable light emitting device having high light-emitting efficiency (light-extraction efficiency) with high luminance and low power consumption, and a method of manufacturing thereof. A partition wall and a heat-resistant planarizing film are formed of a same material so as to be well-adhered to each other, thereby reducing material costs. Either an anode or a cathode is formed on the heat-resistant planarizing film. The partition wall and the heat-resistant planarizing film is adhered to each other without inserting a film having different refractive index therebetween, and therefore reflection of light is not caused in an interface.

The present invention provides a substrate for LED packaging and a fabrication method thereof. The substrate can dissipate heat quickly and enhance light emitting efficiency. For this purpose, several via holes are formed in the substrate and metal layers are coated to act as light reflector. In the substrate, the via holes are filled with the material with high thermal conductivity, such as Copper, to conduct the heat efficiently; and the reflector are coated the metal with high reflection factor to visible light, such as Ag, Au, Al, to enhance the light emitting efficiency.

The invention belongs to the synthesis field of porous silicon materials, and particularly relates to a method for preparing porous silicon by magnesiothermic reduction. The method comprises the following steps: carrying out magnesiothermic reduction reaction based on silicon oxide SiOx (x = 0.5-2) as a raw material to generate a mixture of silicon and magnesium oxide; and then selectively dissolving away magnesium oxide with an acid so as to ultimately obtain a self-supported porous silicon material. Compared with the previous conventional electrochemical anodic etching methods, the method provided by the invention has the advantages that the use of expensive monocrystal silicon wafers is avoided, but simple, easily available and low-cost silicon oxide is used as the raw material, thereby not only reducing the cost but also increasing the yield; and the method has the advantages of simple preparation process, environmental friendliness, high preparation efficiency and good repeatability, is more suitable for industrial production, and is expected to be widely applied in the fields of lithium ion secondary batteries, optical materials, biomedical devices, gas-sensitive devices, etc.

A structure of multi-wavelength light emitting device comprises multi-stacked active layer structure. Each stacked layer comprises lower energy bandgap well 4 and higher energy bandgap barrier layer 3 wherein at least one stacked layer in the device contains nanoparticles. As a result, the emitting wavelengths of the multi-stacked active layer structure consist parts (or all) of the emitting wavelengths come from the stack layers containing nanoparticles, and parts (or all) of the emitting wavelengths come from the stack layers not containing nanoparticles. In another embodiment, parts (or all) of the emitting wavelengths of the multi-stacked active layer structure can be also used to trigger one or more phosphorescences from the phosphors, thus the emitting wavelengths of such a phosphors converted light emitting device may come partially from the multi-stacked active layer itself and partially (or all) from the phosphors.

Disclosed is a light emitting diode (LED) having an active region of a multiple quantum well structure in which well layers and barrier layers are alternately laminated between a GaN-based N-type compound semiconductor layer and a GaN-based P-type compound semiconductor layer. The LED includes a middle barrier layer having a bandgap relatively wider than the first barrier layer adjacent to the N-type compound semiconductor layer and the n-th barrier layer adjacent to the P-type compound semiconductor layer. The middle barrier layer is positioned between the first and n-th barrier layers. Accordingly, positions at which electrons and holes are combined in the multiple quantum well structure to emit light can be controlled, and luminous efficiency can be enhanced. Furthermore, an LED is provided with enhanced luminous efficiency using a bandgap engineering or impurity doping technique.

Exemplary embodiments of the present invention relate to light emitting diodes. A light emitting diode according to an exemplary embodiment of the present invention includes a substrate having a first side edge and a second side edge, and a light emitting structure arranged on the substrate. The light emitting structure includes a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer. A transparent electrode layer including a concave portion and a convex portion is arranged on the second conductivity-type semiconductor layer. A first electrode pad contacts an upper surface of the first conductivity-type semiconductor layer and is located near a center of the first side edge. Two second electrode pads are located near opposite distal ends of the second side edge to supply electric current to the second conductivity-type semiconductor layer. A first pad extension extends from the first electrode pad and a second pad extension extends from each of the two second electrode pads.

The present invention relates to a white organic light emitting device and a method for manufacturing the same, in which a hole transport layer is made to have an energy level higher than an energy level of an excited state of a phosphorescent light emitting layer adjacent thereto for enhancing light emitting efficiency of the hole transport layer without an additional exciton blocking layer, and a dopant content in the phosphorescent light emitting layer is adjusted for preventing color shift from taking place.

The white organic light emitting device includes an anode and a cathode placed on a substrate opposite to each other, a charge generation layer formed between the anode and the cathode, a first stack of a first hole transport layer, a first light emitting layer for emitting a blue light, and a first electron transport layer between the anode and the charge generation layer, and a second stack of a second hole transport layer, a second light emitting layer having a host doped with phosphorescence red and green together, and a second electron transport layer between the charge generation layer and the cathode, wherein the second hole transport layer has an energy level set higher than a triplet excited state energy level of the second light emitting layer.

A GaN-based semiconductor light-emitting device includes (A) a first GaN-based compound semiconductor layer 13 having n-type conductivity, (B) an active layer 15 having a multi-quantum well structure including well layers and barrier layers for separating between the well layers, and (C) a second GaN-based compound semiconductor layer 17 having p-type conductivity. The well layers are disposed in the active layer 15 so as to satisfy the relation d₁<d₂ wherein d₁ is the well layer density on the first GaN-based compound semiconductor layer side in the active layer and d₂ is the well layer density on the second GaN-based compound semiconductor layer side.

There is provided a method of fabricating a vertical light emitting diode. The method comprises the steps of: growing a low doped first conductive semiconductor layer on a sacrificial substrate; forming an aluminum layer on the low doped first conductive semiconductor layer; forming an AAO layer having a large number of holes formed therein by performing anodizing treatment of the aluminum layer; etching and patterning the low doped first conductive semiconductor layer using the aluminum layer with a large number of the holes as a shadow mask to expose a portion of the low doped first conductive semiconductor layer, thereby forming a large number of grooves; removing the aluminum layer remaining on the low doped first conductive semiconductor layer; sequentially forming a high doped first conductive semiconductor layer, an active layer and a second conductive semiconductor layer on the low doped first conductive semiconductor layer with a large number of the grooves; forming a metal reflective layer and a conductive substrate on the second conductive semiconductor layer; separating the sacrificial substrate; and forming an electrode pad on the other surface of the low doped first conductive semiconductor layer, the electrode pad being filled in a large number of the grooves to be in ohmic contact with the high doped first conductive semiconductor layer

A headlamp (1) includes a laser diode (2) for emitting a laser beam and a light-emitting section (5), which contains a fluorescent substance for emitting fluorescence upon receiving the laser beam emitted from the laser diode (2) and diffusing particles (15) for diffusing the laser beam.

The invention relates to an electroluminescent compound and an electroluminescent device comprising the same. The electroluminescent compound is characterized in that the electroluminescent compound is indicated by the following chemical formula (1) and has a non-symmetric structure with L---L' as a benchmark. According to the electroluminescent compound, substituent groups having high efficiency or long service life are respectively combined with pryene compound in a non-symmetric way, so illuminating efficiency and service life are improved and excitation purity and thermal stability are enhanced; the electroluminescent device comprising the same also has excellent excitation purity, illuminating efficiency and long service life; and the electroluminescent compound can be applied to various displaying elements.

Disclosed herein is an organic EL display device, including: a lower electrode provided every first organic EL element for a blue color and every second organic EL element for another color on a substrate; a hole injection/transport layer provided every first and second organic EL elements; a second organic light emitting layer for another color provided on said hole injection/transport layer for said second organic EL element; a connection layer made of a low-molecular material and provided over an entire surface of said hole injection/transport layer for said second organic light emitting layer and said first organic EL element; a first organic light emitting layer for a blue color provided over an entire surface of said connection layer; and an electron injection/transport layer and an upper electrode provided over an entire surface of said organic light emitting layer in order.

The invention provides a method which uses a graphic substrate to improve the illumination efficiency of a GaN-based efficiency, comprising the steps as follows: a silicon dioxide film is deposited on a sapphire substrate; a photoresist graphic array is optically etched; the photoresist graphic array is taken as a mask so as to etch the silicon dioxide film with the graphic structure; the silicon dioxide film with the graphic structure is taken as a mask so as to etch the sapphire substrate and the graphics is etched onto the sapphire substrate; the sapphire substrate is thoroughly cleaned so as to form a pyramid structure with triangular sections; a low-temperature nucleation layer grows on the graphic sapphire substrate; temperature is continuously increased on the low-temperature nucleation layer so as to grow an n-typed mixed GaN layer and an array structure which has low dislocation density and V-shaped holes on the surface; a multiple quantum well layer and a p-typed material layer required when the LED structure material grows continue to grow; furthermore, the final surface is led to still have the array structure with V-shaped holes.

A liquid crystal display device is provided which is capable of improving quality of moving images. A field dividing driving operation is performed in which an odd field during which each of scanning electrodes in odd-numbered rows is sequentially driven and an even field during which each of scanning electrodes in even-numbered rows is sequentially driven occur, alternately and repeatedly, with time width of a refresh rate. In the former half of the odd field, display data is written in each of pixel regions corresponding to scanning electrodes in odd-numbered rows and, in the latter half of the odd field, black data is written in each of the pixel regions corresponding to scanning electrodes in the odd-numbered rows. In the former half of the even field, display data is written in each of pixel regions corresponding to scanning electrodes in the even-numbered rows and, in the latter half of the even field, black data is written in each of pixel regions corresponding to scanning electrodes in the even-numbered rows.