203results about How to "Light emission efficiency" patented technology

A method of making an OLED display having a plurality of OLED devices includes providing a plurality of OLED devices on a substrate, such OLED devices sharing a common light-transmissive electrode; forming a patterned conductive layer structure over the common light-transmissive electrode to define wells in alignment with emissive areas of one or more OLED devices; and providing optical material into one or more wells

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.

A light-emitting element containing a light-emitting material and having high light emission efficiency is provided. The light-emitting element includes a host material and a guest material. The host material includes at least a first molecule and a second molecule having the same molecular structure. The guest material has a function of exhibiting fluorescence or converting triplet excitation energy into light emission. The first molecule and the second molecule 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 skeleton includes at least one of a π-electron rich heteroaromatic skeleton and an aromatic amine skeleton and the second skeleton includes a π-electron deficient heteroaromatic skeleton. The first molecule and the second molecule have a function of forming an excited complex.

According to the nitride semiconductor device with the active layer made of the multiple quantum well structure of the present invention, the performance of the multiple quantum well structure can be brought out to intensify the luminous output thereof thereby contributing an expanded application of the nitride semiconductor device. In the nitride semiconductor device comprises an n-region having a plurality of nitride semiconductor films, a p-region having a plurality of nitride semiconductor films, and an active layer interposed therebetween, a multi-film layer with two kinds of the nitride semiconductor films is formed in at least one of the n-region or the p-region.

To provide a light-emitting element with high light emission efficiency, a long lifetime, and reduced driving voltage. To provide a light-emitting element including an anode, a cathode, and a plurality of light-emitting layers which are in contact with each other so that a stacked structure is formed, between the anode and the cathode, in which the plurality of light-emitting layers are formed with a first light-emitting layer which is close to the anode and a second light-emitting layer which is close to the cathode, the first light-emitting layer and the second light-emitting layer each include a host material, a hole-transporting material, and a light-emitting material, and the concentration of the hole-transporting material in the first light-emitting layer is higher than the concentration of the hole-transporting material in the second light-emitting layer.

There is provided a light source for an illumination apparatus and a method of manufacturing the same. The light source includes a light emitting device; a power unit module supplying an electrical signal to the light emitting device; a support unit having the light emitting device thereon and discharging heat generated by the light emitting device to the outside; and a housing unit covering and protecting the light emitting device, the power unit module and the support unit. The light emitting device is disposed to have a height greater than that of a contact region between the power unit module and the housing unit with relation to a lower edge of the housing unit.

A semiconductor device comprises an active layer having a quantum well structure, the active layer including a well layer and a barrier layer and being sandwiched by a first conductivity type layer and a second conductivity type layer, wherein a first barrier layer is provided on side of the first conductivity type layer in the active layer and a second barrier layer is provided on the side of the second conductivity type layer in the active layer, at least one well layer is sandwiched thereby, and the second barrier layer has a band gap energy lower than that of the first barrier layer in the form of asymmetric barrier layer structure, where the second conductivity type layer preferably includes a carrier confinement layer having a band gap energy higher than that of the first barrier layer, resulting in a reverse structure in each of conductivity type layer in respect to the asymmetric structure of the active layer to provide a waveguide structure having excellent crystallinity and device characteristics in the nitride semiconductor light emitting device operating at a wavelength of 380 nm or shorter.

The light guide plate 32 has a light receiving portion 36 on one side thereof to receive light emitted by the LED 24 and a flexible light guide body 35 for transforming the light received by the light receiving portion 36 into planar light. The light guide body 35 is arranged along the liquid crystal panel 23 and has a plurality of light scattering portions 30 arranged on an outer surface thereof in a propagation direction of light emitted by the LED 24. Since the light guide plate 32 comprises a flexible member and thus can be arranged in a curved shape conforming to the liquid crystal panel 23 having a curved surface portion, the curved surface portion of the liquid crystal panel 23 can be illuminated uniformly. Further, the provision of the light scattering portions 30 can enhance a light reception efficiency and light emission efficiency even if the light guide plate 32 is thin.

An alternating current light-emitting device includes a substrate, a plurality of microdie light-emitting elements formed on the substrate, a rectifying element-dedicated member formed on a surface of a portion of microdie light-emitting elements, a rectifying unit formed on the rectifying element-dedicated member and provided with at least four rectifying elements forming a Wheatstone bridge circuit, and an electrically conductive structure electrically connecting the rectifying elements and the microdie light-emitting elements. With the rectifying unit being formed on the rectifying element-dedicated member, the rectifying elements are highly tolerant of reverse bias and feature low starting forward bias. Also, the present invention provides a method for fabricating an alternating current light-emitting device.

A nitride light emitting diode, on a patterned substrate, comprising a nitride interlayer having at least two periods of alternating layers of InxGa1-xN and InyGa1-yN where 0<x<1 and 0≦y<1, and a nitride based active region having at least one quantum well structure on the nitride interlayer.

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.

A display apparatus that includes: a plurality of light-emitting devices disposed on a substrate with an accumulation of, in this or inverse order, a light transmissive electrode layer, a functional layer including a light-emitting layer, and an opposing electrode layer; and a color conversion layer that is provided on a side of the light transmissive electrode layer for any of the light-emitting devices, and applies color conversion to an emitted light generated by the light-emitting layer for the light-emitting device. In the display apparatus, the light-emitting devices each have a reflective surface on a position where the light-emitting layer is sandwiched with the light transmissive electrode layer, and an optical distance between the reflective surface and the light-emitting layer varies by the light-emitting devices depending on provision of the color conversion layer.

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.

An organic electroluminescence device including a lower electrode disposed on a substrate, an organic layer having at least a light emission layer and disposed above the lower electrode, and upper electrode having a transparent conductive film and disposed above the organic layer, in which the device has an electron injecting layer between the organic layer and the upper electrode. The electron injecting layer has a buffer layer comprising an insulative material and a mixed layer comprising an organic material that has an electron transporting property and a metal material that has an electron injecting property.

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.

A light emitting device having a simple structure that can be easily manufactured, attaining high light emitting efficiency stably for a long time is obtained, which light emitting device includes: a GaN substrate as a nitride semiconductor substrate and, on a first main surface of the nitride semiconductor substrate, an n-type AlxGa1-xN layer, a p-type AlxGa1-xN layer positioned further than the n-type AlxGa1-xN layer viewed from the nitride semiconductor substrate, and a quantum well positioned between the n-type AlxGa1-xN layer and the p-type AlxGa1-xN layer. In the light emitting device, specific resistance of the nitride semiconductor substrate is at most 0.5 Ω·cm, the side of p-type AlxGa1-xN layer is mounted face-down, and the light is emitted from the second main surface 1a that is opposite to the first main surface of the nitride semiconductor substrate. The second main surface 1a of nitride semiconductor substrate has trenches formed therein.

A nanowire light emitting diode (LED) and method of emitting light employ a plasmonic mode. The nanowire LED includes a nanowire having a semiconductor junction, a shell layer coaxially surrounding the nanowire, and an insulating layer, which is plasmonically thin, isolating the shell layer from the nanowire. The shell layer supports a surface plasmon that couples to the semiconductor junction by an evanescent field. Light is generated in a vicinity of the semiconductor junction and the surface plasmon is coupled to the semiconductor junction during light generation. The coupling enhances one or both of an efficiency of light emission and a light emission rate of the LED. A method of making the nanowire LED includes forming the nanowire, providing the insulating layer on the surface of the nanowire, and forming the shell layer on the insulating layer in the vicinity of the semiconductor junction.

Disclosed is a light emitting device having a plurality of light emitting cells and a package having the same mounted thereon. The light emitting device includes a plurality of light emitting cells which are formed on a substrate and each of which has an N-type semiconductor layer and a P-type semiconductor layer located on a portion of the N-type semiconductor layer. The plurality of light emitting cells are bonded to a submount substrate. Accordingly, heat generated from the light emitting cells can be easily dissipated, so that a thermal load on the light emitting device can be reduced. Meanwhile, since the plurality of light emitting cells are electrically connected using connection electrodes or electrode layers formed on the submount substrate, it is possible to provide light emitting cell arrays connected to each other in series. Further, it is possible to provide a light emitting device capable of being directly driven by an AC power source by connecting the serially connected light emitting cell arrays in reverse parallel to each other.

An organic EL element including: a transparent supporting substrate; a diffraction grating having a concavity and convexity layer with first concavities and convexities formed on a surface thereof and disposed on the transparent supporting substrate; and a transparent electrode, an organic layer, and a metal electrode which are stacked in this order on the diffraction grating and formed into such shapes that a shape of the first concavities and convexities formed on the surface of the diffraction grating is maintained, the organic layer comprising at least a light emitting layer. The organic EL element satisfies specified conditions (A) to (C).

According to the nitride semiconductor device with the active layer made of the multiple quantum well structure of the present invention, the performance of the multiple quantum well structure can be brought out to intensify the luminous output thereof thereby contributing an expanded application of the nitride semiconductor device. In the nitride semiconductor device comprises an n-region having a plurality of nitride semiconductor films, a p-region having a plurality of nitride semiconductor films, and an active layer interposed therebetween, a multi-film layer with two kinds of the nitride semiconductor films is formed in at least one of the n-region or the p-region,

A multi-stack package light emitting diode (LED) includes an LED chip, a first fluorescent powder layer, a first optical bandpass filter layer and a second fluorescent powder layer. The LED chip generates an LED light. The first fluorescent powder layer and the second fluorescent powder layer respectively have a first fluorescent powder and a second fluorescent powder. The first fluorescent powder and the second fluorescent powder are excited by the LED light to respectively generate a first excitation light and a second excitation light. The first optical bandpass filter layer allows the LED light and the first excitation light to pass and reflects the second excitation light. A wavelength of the LED light is shorter than a wavelength of the second excitation light. The wavelength of the second excitation light is shorter than a wavelength of the first excitation light. Therefore, the multi-stack package LED improves a light emission efficiency.

A method of forming a phosphor layer of a gas discharge tube provided with the phosphor layer on an internal surface of an elongated tubular vessel forming a discharge space. The method includes the steps of introducing a slurry of phosphor powder and a binding resin dispersed in a medium into the tubular vessel, holding the tubular vessel sideways to deposit the phosphor powder and the binding resin in the tubular vessel, and removing the medium from the tubular vessel, thereby forming a phosphor layer on one side of the internal surface of the tubular vessel.

A semiconductor light-emitting device includes: a support; a semiconductor light-emitting element bonded to the support and comprising a first electrode, a second electrode, and a semiconductor layer including at least an active layer, at least one of the first and second electrodes overlying the semiconductor layer; and a wiring metal formed to extend from above a portion of an upper surface of the support not underlying the semiconductor light-emitting element to one said electrode overlying the semiconductor layer. The electrode is fed with power through the wiring metal.

A light-emitting diode element includes: an n-type conductive layer 2 being made of a gallium nitride-based compound, a principal surface being an m-plane; a semiconductor multilayer structure 21 provided on a first region 2a of the principal surface of the n-type conductive layer 2, the semiconductor multilayer structure 21 including a p-type conductive layer 4 and an active layer 3; a p-electrode 5 provided on the p-type conductive layer 4; a conductor portion 9 provided on a second region 2b of the principal surface of the n-type conductive layer 2, the conductor portion 9 being in contact with an inner wall of a through hole 8; and an n-type front surface electrode 6 provided on the second region 2b of the principal surface of the n-type conductive layer 2, the n-type front surface electrode 6 being in contact with the conductor portion 9.

To provide a light-emitting element with high light emission efficiency, a long lifetime, and reduced driving voltage. To provide a light-emitting element including an anode, a cathode, and a plurality of light-emitting layers which are in contact with each other so that a stacked structure is formed, between the anode and the cathode, in which the plurality of light-emitting layers are formed with a first light-emitting layer which is close to the anode and a second light-emitting layer which is close to the cathode, the first light-emitting layer and the second light-emitting layer each include a host material, a hole-transporting material, and a light-emitting material, and the concentration of the hole-transporting material in the first light-emitting layer is higher than the concentration of the hole-transporting material in the second light-emitting layer.

An optoelectronic device is disclosed. The optoelectronic device comprises a transparent conductive substrate, an optoelectronic element, and a base. The transparent conductive substrate comprises a transparent plate, a transparent electrode film formed on the transparent plate, and an insulating part formed on the transparent plate. The insulating part divides the transparent electrode film into a first transparent electrode film and a second transparent electrode film that non-conduct each other. The optoelectronic element comprising a positive electrode and a negative electrode is disposed on the transparent conductive substrate and electrically connected to the first transparent electrode film and the second transparent electrode film individually. The base is formed with an opening that has a reflective surface on the bottom of the opening, and the optoelectronic element is held in the opening in a manner of suspending from or connecting with the bottom of the opening.

A method for producing a gallium nitride based compound semiconductor light emitting device which is excellent in terms of the light emitting properties and the light emission efficiency and a lamp is provided. In such a method for producing a gallium nitride based compound semiconductor light emitting device, which is a method for producing a GaN based semiconductor light emitting device having at least a buffer layer, an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer on a translucent substrate, on which an uneven pattern composed of a convex shape and a concave shape is formed, the buffer layer is formed by a sputtering method conducted in an apparatus having a pivoted magnetron magnetic circuit and the buffer layer contains AlN, ZnO, Mg, or Hf.

There is provided a projection type image display device capable of simplifying cooling of light source elements of light source arrays, thereby reducing the size of refrigerating means, dispensing with complicated temperature adjustment and reducing the manufacturing cost and the electric power cost. The projection type image display device can attain projection light by modulating light beams of at least three primary colors in accordance with image information and synthesizing the modulated light beams. The projection type image display device comprises a light source unit constituted by arranging a plurality of light source elements hierarchically so as to conduct the light beams of the colors to irradiation surfaces of a synthesizing prism, the light source elements comprising light source arrays each of plural light emitting elements arranged on one and same substrate, the light source arrays being arranged on heat receiving plates respectively; refrigerating means including at least a refrigerant compressor, a condenser, a pressure reducing device and a refrigerant pipe constituting an evaporator; and auxiliary cooling means lower in cooling capacity than the refrigerating means. Of the plural light source arrays, those relatively large in the amount of heat generated are connected to the refrigerating means, while the others are connected to the auxiliary cooling means.

A semiconductor device comprises an active layer having a quantum well structure, the active layer including a well layer and a barrier layer and being sandwiched by a first conductivity type layer and a second conductivity type layer, wherein a first barrier layer is provided on side of the first conductivity type layer in the active layer and a second barrier layer is provided on the side of the second conductivity type layer in the active layer, at least one well layer is sandwiched thereby, and the second barrier layer has a band gap energy lower than that of the first barrier layer in the form of asymmetric barrier layer structure, where the second conductivity type layer preferably includes a carrier confinement layer having a band gap energy higher than that of the first barrier layer, resulting in a reverse structure in each of conductivity type layer in respect to the asymmetric structure of the active layer to provide a waveguide structure having excellent crystallinity and device characteristics in the nitride semiconductor light emitting device operating at a wavelength of 380 nm or shorter.