1277results about How to "Improve emission efficiency" patented technology

An organic polymeric phosphorescent compound that is stable and emits very highly efficient phosphorescence, used as a material of an organic light-emitting device is provided. Also, an organic light-emitting device employing the organic polymeric phosphorescent compound's provided. The phosphorescent compound according to the present invention is a neutral organic polymeric phosphorescent compound emitting phosphorescence and used in an organic light-emitting device, characterized in that a phosphorescent unit being a repeat unit for emitting phosphorescence and a carrier transporting unit being a repeat unit for transporting a carrier are included.

Disclosed herein is a light emitting device including one or more light emitting diodes to primarily emit light having different wavelengths in the wavelength range of ultraviolet rays and / or blue light, and a wavelength-conversion means to convert the primary light into secondary light in the visible light wavelength range. The light emitting device of the current invention has a high color temperature of 2000 to 8000 K or 10000 K and a high color rendering index of 90 or more, thus easily realizing desired emission on the color coordinate system. Therefore, the lighting emitting device is applicable to mobile phones, notebook computers, and keypads or backlight units for various electronic products, and, in particular, automobiles and exterior and interior lighting fixtures.

Affords a GaN substrate from which enhanced-emission-efficiency light-emitting and like semiconductor devices can be produced, an epi-substrate in which an epitaxial layer has been formed on the GaN substrate principal surface, a semiconductor device, and a method of manufacturing the GaN substrate. The GaN substrate is a substrate having a principal surface with respect to whose normal vector the [0001] plane orientation is inclined in two different off-axis directions.

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.

A light-emitting element with high emission efficiency. The light-emitting element includes a first organic compound, a second organic compound, and a guest material. The LUMO level of the first organic compound is lower than the LUMO level of the second organic compound. The HOMO level of the first organic compound is lower than the HOMO level of the second organic compound. The HOMO level of the guest material is higher than the HOMO level of the second organic compound. The energy difference between the LUMO level of the guest material and the HOMO level of the guest material is larger than the energy difference between the LUMO level of the first organic compound and the HOMO level of the second organic compound. The guest material has a function of converting triplet excitation energy into light emission. The first organic compound and the second organic compound form an exciplex.

The compositions, methods and systems of the invention provide nanocrystal taggants for unobtrusive monitoring of objects. Objects can be tagged with nanocrystal taggant compositions for detection of informative invisible emissions on illumination with appropriate excitation wavelengths.

An object is to provide an organometallic complex that can emit red light. Another object is to provide an organometallic complex having high emission efficiency. Still another object is to provide an organometallic complex that can emit red light with high luminous efficiency. The present invention provides an organometallic complex having a structure represented by the following general formula (G1′).In the formula, Ar represents an aryl group having 6 to 25 carbon atoms; R1 represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms; R2 to R8 each represent any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen group; at least one of pairs R3 and R4, R4 and R5, and R5 and R6 may be bound to each other to form a ring; and M represents a central metal of Group 9 elements and Group 10 elements.

An organic light emitting display (OLED) device includes a substrate, a plurality of first electrodes, a plurality of light emitting layers, a second electrode, a power supply line, a third electrode, and an encapsulation member. The third electrode that is formed on the power supply line and the second electrode that is formed on the light emitting layers extend to a contact region that is in a peripheral region of the substrate. The third electrode and the second electrodes have an uneven pattern in the contact region.

The invention provides a light-emitting device, a manufacturing method thereof, and an electronic apparatus which can improve the emission efficiency of light, obtain uniform brightness within a display surface in high reliability, in particular, and which can suppress lowering of the emission efficiency of light due to various wiring line structures, even though a large screen is performed. In a light-emitting device having a light-emitting element in which a first electrode on a base substrate, a functional layer having a light-emitting layer, and a second electrode are sequentially deposited, the first electrode and the second electrode are reflective, and the second electrode has an opening through which light from the light-emitting layer passes.

According to the invention, a Group III nitride compound semiconductor light-emitting element is provided with a light-emitting layer comprising two layers of different in ratio of AlGaInN composition, and emitting light with an emission peak wavelength in an ultraviolet region and light with an emission peak wavelength in a visible region. The light-emitting element and a fluorescent material excited by light in the ultraviolet region are combined to configure a light emitting device.

An object is to provide a light-emitting element which includes an exciplex being used as an energy donor capable of efficiently transferring energy to a substance exhibiting thermally activated delayed fluorescence. The exciplex comprises two kinds of substances and its singlet and triplet excited states are close to each other. Thus, by making light emission of the exciplex overlap with an absorption band on the longest wavelength side which corresponds to absorption by the substance exhibiting thermally activated delayed fluorescence, i.e., an energy acceptor, in a singlet excited state, it becomes possible to achieve efficient energy transfer from a singlet excited state of the exciplex to a singlet excited state of the substance exhibiting thermally activated delayed fluorescence, and it also becomes possible to achieve efficient energy transfer from a triplet excited state of the exciplex to a triplet excited state of the substance exhibiting thermally activated delayed fluorescence.

To provide a phosphor having an emission characteristic such that a peak wavelength of light emission is in a range from 580 to 680 nm, and having a high emission intensity, and having a flat excitation band with high efficiency for excitation light in a broad wavelength range from ultraviolet to visible light (wavelength range from 250 nm to 550 nm). For example, Ca3N2(2N), AlN(3N), Si3N4(3N), Eu2O3(3N) are prepared, and after weighing and mixing a predetermined amount of each raw material, raw materials are fired at 1500° C. for 6 hours, thus obtaining the phosphor including a product phase expressed by a composition formula CaAlSiN3:Eu and having an X-ray diffraction pattern satisfying a predetermined pattern.

A light emitting device includes a substrate having a first surface and a second surface not parallel to the first surface, and a light emission layer disposed over the second surface to emit light. The light emission layer has a light emission surface which is not parallel to the first surface.

A white organic light emitting element, a white organic light emitting display device, and a method of manufacturing the white organic light emitting element are provided. The organic light emitting element includes a multi-layered emission layer structure. The multi-layered emission layer structure includes a first electroluminescent layer and a second electroluminescent layer that are arranged to overlap at first area of the white organic light emitting element. The lights from the first and second electroluminescent layers collectively form white light. Among the first and second electroluminescent layers, one of the EL layers is extended out to the second area of the white organic light emitting element. A plurality of color filter elements are used to filter the white light to generate colored lights at the corresponding sub pixel regions.

Disclosed is a wavelength conversion member that is provided with: a light transmissive member including a light input plane into which excitation light is inputted, and a light output plane from which wavelength converted light is outputted; and a semiconductor fine particle phosphor, which is dispersed in the light transmissive member, and which absorbs the excitation light, converts the wavelength, and emits light. The dispersion concentration of the semiconductor fine particle phosphor in the direction parallel to the light traveling direction, i.e., the direction connecting the light input plane and the light output plane, is lower than the dispersion concentration of the semiconductor fine particle phosphor in the direction orthogonal to the light traveling direction.

A white organic light emitting diode (OLED) includes an emission layer between two electrodes. The emission layer comprises two or more kinds of compounds for the host and two or more kinds of compounds for the dopant that facilitate production of a white color. Among the two or more kinds of compounds for the host, at least one is a hole transporting material and the other is an electron transporting material. The white OLED has improved stability which increases its efficiency and life.

To provide a phosphor having an emission spectrum with a broad peak in a range from yellow color to red color (580 nm to 680 nm) and an excellent excitation band on the longer wavelength side from near ultraviolet / ultraviolet of excitation light to visible light (250 nm to 550 nm), and having an improved emission intensity. The phosphor is provided, which is given by a general composition formula expressed by MmAaBbOoNn:Z, (wherein element M is more than one kind of element having bivalent valency, element A is more than one kind of element having tervalent valency selected from the group consisting of Al, Ga, In, Tl, Y, Sc, P, As, Sb, and Bi, element B is more than one kind of element having tetravalent valency, O is oxygen, N is nitrogen, and element Z is more than one kind of element selected from rare earth elements or transitional metal elements, satisfying m>0, a>0, b>0 o≧0, and n=2 / 3m+a+4 / 3b−2 / 3o), and further containing boron and / or fluorine.

In a display device having a color filter, a color material dispersed layer having the function of absorbing light of specific wavelengths in the visible light beam region is provided on the optical path so that the light absorption peak of this color material dispersed layer in the visible light beam region is located in the range of ±30 nm from the overlap point in the spectral transmission properties of each color of the color filter. Further, the color material dispersed layer is provided on a filter as a constituent part of the back light of the display. This filter has, as its substrate, a thermoplastic resin having a thickness of 30-350 micrometers and has a transmission in the maximum absorption wavelength in the color material dispersed layer of not more than 75%. The back light has, as its light source, a fluorescent lamp comprising a three band tube, and its emission color is subjected to color correction by an auxiliary filter having an organic color material dispersed layer provided on the illuminating light path.

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.

The invention provides an oxynitride phosphor represented by a composition formula M1-aCeaSibAlcOdNe, 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.

In the nitride semiconductor device of the present invention, an active layer 12 is sandwiched between a p-type nitride semiconductor layer 11 and an n-type nitride semiconductor layer 13. The active layer 12 has, at least, a barrier layer 2a having an n-type impurity; a well layer 1a made of a nitride semiconductor that includes In; and a barrier layer 2c that has a p-type impurity, or that has been grown without being doped. An appropriate injection of carriers into the active layer 12 becomes possible by arranging the barrier layer 2c nearest to the p-type layer side.

An object is to provide a light-emitting element which uses a plurality of kinds of light-emitting dopants and has high emission efficiency. In one embodiment of the present invention, a light-emitting device, a light-emitting module, a light-emitting display device, an electronic device, and a lighting device each having reduced power consumption by using the above light-emitting element are provided. Attention is paid to Förster mechanism, which is one of mechanisms of intermolecular energy transfer. Efficient energy transfer by Förster mechanism is achieved by making an emission wavelength of a molecule which donates energy overlap with the longest-wavelength-side local maximum peak of a graph obtained by multiplying an absorption spectrum of a molecule which receives energy by a wavelength raised to the fourth power.

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.

The present invention is a semiconductor structure for light emitting devices that can emit in the red to ultraviolet portion of the electromagnetic spectrum. The semiconductor structure includes a first cladding layer of a Group III nitride, a second cladding layer of a Group III nitride, and an active layer of a Group III nitride that is positioned between the first and second cladding layers, and whose bandgap is smaller than the respective bandgaps of the first and second cladding layers. The semiconductor structure is characterized by the absence of gallium in one or more of these structural layers.

A GaN based semiconductor light emitting device has: an active layer disposed between an n-type layer and a p-type layer; and a polycrystalline nitride based semiconductor uneven layer disposed between the n-type layer and the active layer. The active layer is formed uneven according to the uneven form of the polycrystalline nitride based semiconductor uneven layer.

Provided is a light-emitting element including a fluorescence-emitting material with high emission efficiency. The light-emitting element includes a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a first organic compound, a second organic compound, and a guest material. The first organic compound has a function of emitting a thermally activated delayed fluorescence at room temperature. The guest material has a function of emitting fluorescence. A HOMO level of the first organic compound higher than or equal to a HOMO level of the second organic compound. A LUMO level of the first organic compound is lower than or equal to a LUMO level of the second organic compound.

A phosphor with high efficiency having an excitation band corresponding to light of the ultraviolet-visible (300 to 550 nm) wavelength region emitted from a light emitting element which emits blue or ultraviolet light is provided. Commercially available CaO [3N], Si3N4 [3N], and Eu2O3 [3N] are prepared, respective materials are weighed and mixed to have a mol ratio of CaO:Si3N4:Eu2O3=1.4775:1:0.01125, and then the mixture is heated to 1600° C. by a heating rate of 15° C. / min under a nitrogen atmosphere and retained and fired at 1600° C. for three hours. Thereafter, the raw materials are cooled down from 1600° C. to 200° C. for an hour to thereby produce a phosphor having a composition formula Ca1.58Si3O1.63N4.35:Eu0.024.