1182 results about "Emission efficiency" patented technology

Organic light emitting devices are described wherein the emissive layer comprises a host material containing a fluorescent or phosphorescent emissive molecule, which molecule is adapted to luminesce when a voltage is applied across the heterostructure, wherein an intersystem crossing molecule of optical absorption spectrum matched to the emission spectrum of the emissive molecule enhances emission efficiency.

As a novel substance having a novel skeleton, an organometallic complex having high emission efficiency and improved color purity is provided. The color purity is improved by reducing the half width of an emission spectrum. The organometallic complex is represented by General Formula (G1). In General Formula (G1), at least one of R1 to R4 represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and the others each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. Note that the case where all of R1 to R4 represent alkyl groups each having 1 carbon atom is excluded. Further, R5 to R9 each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

As a novel substance having a novel skeleton, an organometallic complex with high emission efficiency which achieves improved color purity by a reduction of half width of an emission spectrum is provided. One embodiment of the present invention is an organometallic complex in which a β-diketone and a six-membered heteroaromatic ring including two or more nitrogen atoms inclusive of a nitrogen atom that is a coordinating atom are ligands. In General Formula (G1), X represents a substituted or unsubstituted six-membered heteroaromatic ring including two or more nitrogen atoms inclusive of a nitrogen atom that is a coordinating atom. Further, R1 to R4 each represent a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

Disclosed is a light-emitting element having high emission efficiency, capable of driving at low voltage, and showing a long lifetime. The light-emitting element contains a compound between a pair of electrodes, and the compound is configured to give a first peak of m / z around 202 and a second peak of m / z around 227 in a mass spectrum. The first and second peaks are product ions of the compound and possess compositions of C16H9 and C17H10N, respectively, which are derived from a dibenzo[f,h]quinoline unit.

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.

Provided is 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 that of the second organic compound, and the HOMO level of the first organic compound is lower than that of the second organic compound. The LUMO level of a guest material is higher than that of the first organic compound, and the HOMO level of the guest material is lower than that 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.

Provided is a novel substance that can emit phosphorescence. Alternatively, provided is a novel substance with high emission efficiency. An organometallic complex in which a 4-arylpyrimidine derivative is a ligand and iridium is a central metal is provided. Specifically, an organometallic complex having a structure represented by a general formula (G1) is provided. In the general formula (G1), R1 represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, R2 represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and a substituted or unsubstituted phenyl group, R3 represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and Ar1 represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms.

A light-emitting element having a long lifetime is provided. A light-emitting element exhibiting high emission efficiency in a high luminance region is provided. A light-emitting element includes a light-emitting layer between a pair of electrodes. The light-emitting layer contains a first organic compound, a second organic compound, and a phosphorescent compound. The first organic compound is represented by a general formula (G0). The molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000. The second organic compound is a compound having an electron-transport property. In the general formula (G0), Ar1 and Ar2 each independently represent a fluorenyl group, a spirofluorenyl group, or a biphenyl group, and Ar3 represents a substituent including a carbazole skeleton.

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.

An object of the present invention is to provide a light emitting device exhibiting a superior emission efficiency which enables easy adjustment of an emission spectrum.The above object is achieved by a light emitting device comprising a semiconductor light emitting element and a phosphor layer, which has an area A and an area B of different emission spectra, and in which a plurality of phosphor portions are disposed on a plane such that identical phosphor portions do not adjoin one another, and the surface area occupied by specific phosphor portions in the phosphor layer is different in area A and area B.

To provide a light-emitting element with high emission efficiency and low driving voltage. The light-emitting element includes a guest material and a host material. A HOMO level of the guest material is higher than a HOMO level of the host material. An energy difference between the LUMO level and a HOMO level of the guest material is larger than an energy difference between the LUMO level and a HOMO level of the host material. The guest material has a function of converting triplet excitation energy into light emission. An energy difference between the LUMO level of the host material and the HOMO level of the guest material is larger than or equal to energy of light emission of the guest material.

Provided is a novel light-emitting element, a light-emitting element with a long lifetime, or a light-emitting element with high emission efficiency. The light-emitting element includes an EL layer between a pair of electrodes. The EL layer includes at least a light-emitting layer containing a fluorescent substance and a host material, a first electron-transport layer containing a first electron-transport material, and a second electron-transport layer containing a second electron-transport material, which are in contact with each other and in this order. The LUMO level of each of the host material and the second electron-transport material is higher than the LUMO level of the first electron-transport material.

An Organic Light Emitting Display (OLED) that is capable of decreasing the number of output lines for a data driver using a demultiplexer, displaying an image with uniform brightness, and adjusting white balance includes: a plurality of red, green and blue sub-pixels, and each sub-pixel is provided with an auxiliary capacitor to compensate a decreased driving voltage. The respective auxiliary capacitors are different in capacitance according to emission efficiency of the red, green and blue sub-pixels. The auxiliary capacitor of the green sub-pixel has a larger capacitance than the auxiliary capacitor of the red sub-pixel, and the auxiliary capacitor of the red sub-pixel has a larger capacitance than the auxiliary capacitor of the blue sub-pixel. This enables the white balance to be adjusted with the same data voltage.

To provide a light-emitting element with high emission efficiency and low driving voltage. The light-emitting element includes a guest material and a host material. A LUMO level of the guest material is lower than a LUMO level of the host material. An energy difference between the LUMO level and a HOMO level of the guest material is larger than an energy difference between the LUMO level and a HOMO level of the host material. The guest material has a function of converting triplet excitation energy into light emission. An energy difference between the LUMO level of the guest material and the HOMO level of the host material is larger than or equal to energy of light emission of the guest material.

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.

A light-emitting element having extremely high efficiency of approximately 25% is provided. The light-emitting element includes a light-emitting layer which contains a phosphorescent guest, an n-type host, and a p-type host, where the light-emitting layer is interposed between an n-type layer including the n-type host and a p-type layer including the p-type host, and where the n-type host and the p-type host are able to form an exciplex in the light-emitting layer. The light-emitting element exhibits an extremely high emission efficiency (power efficiency of 74.3 lm / W, external quantum efficiency of 24.5%, energy efficiency of 19.3%) at a low driving voltage (2.6 V) at which luminance of 1200 cd / m2 is attainable.

An opposed reflecting mirror is provided so as to face a light source. The opposed reflecting mirror is configured to reflect light rays, emitted from the light source, so as to allow the reflected light rays to advance in a predetermined direction. A light guide body having a plurality of reflecting surfaces is provided to permit the incidence of light rays supplied from the opposed reflecting mirror and to reflect the incident light rays. The plurality of reflecting surfaces are located at different positions in a sliding split manner along the direction of light rays supplied from the opposed reflecting mirror. By virtue of this construction, a light emitting apparatus can be provided in which, while making the best use of a feature of LED, i.e., a small thickness, impressive illumination of an elongated shape by one light emitting device and high external emission efficiency can be realized. The arrangement of a plurality of light emitting apparatuses of the above type at predetermined intervals can provide on-vehicle or other displays of a novel and unconventional design.

The present invention provides a white organic light-emitting element high in the emission efficiency. In particular, the invention provides a white organic light-emitting element that has an emission spectrum having peaks in the respective wavelength regions of red color, green color and blue color and is high in the emission efficiency. Since a spectrum region lowest in the emission efficiency is a red region, by introducing a reddish phosphorescent material, a highly efficient white organic light-emitting element is obtained. At this time, in order to inhibit the reddish phosphorescent material from singularly emitting, as shown in FIG. 1, a distance between a second emission region 114 where a reddish phosphorescent material 124 is a luminescent material and a first emission region 113 that exhibits emission in a shorter wavelength side than the second emission region is separated. In a configuration shown in FIG.1, it is preferable to use an electron transport material in a layer 115 between the first emission region and the second emission region and more preferable to use a hole block material.

To provide a phosphor having an emission spectrum with a broad peak in a range from green color to yellow color, having a broad and flat excitation band capable of using lights of broad range from near ultraviolet / ultraviolet to blue lights as excitation lights, and having excellent emission efficiency and luminance. The problem is solved by providing the phosphor expressed by a general composition formula MmAaBbOoNn:Z (where element M is one or more kinds of elements having bivalent valency, element A is one or more kinds of elements having tervalent valency, element B is one or more kinds of elements having tetravalent valency, O is oxygen, N is nitrogen, and element Z is one or more kinds of elements acting as the activator.), satisfying 4.0<(a+b) / m<7.0, a / m≧0.5, b / a>2.5, n>o, n=2 / 3 m+a+4 / 3 b−2 / 3 o.

A light-emitting element having extremely high efficiency of approximately 25% is provided. The light-emitting element includes a light-emitting layer which contains a phosphorescent guest, an n-type host, and a p-type host, where the light-emitting layer is interposed between an n-type layer including the n-type host and a p-type layer including the p-type host, and where the n-type host and the p-type host are able to form an exciplex in the light-emitting layer. The light-emitting element exhibits an extremely high emission efficiency (power efficiency of 74.3 lm / W, external quantum efficiency of 24.5%, energy efficiency of 19.3%) at a low driving voltage (2.6 V) at which luminance of 1200 cd / m2 is attainable.

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.

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 a local maximum peak on the longest wavelength side of a graph obtained by multiplying an absorption spectrum of a molecule which receives energy by a wavelength raised to the fourth power.

To provide a phosphor having a broad emission spectrum in a range of blue color (peak wavelength from 400 nm to 500 nm), having a broad and flat excitation band in the range of near ultraviolet / ultraviolet, and having excellent emission efficiency and emission intensity / luminance. The phosphor is expressed by a general composition formula MmAaBbOoNn:Z (where element M is more than one kind of element having bivalent valency, element A is more than one kind of element having tervalent valency, 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 acting as an activator.), satisfying 5.0<(a+b) / m<9.0, 0≦a / m≦2.0, 0≦o<n, n=2 / 3m+a+4 / 3b−2 / 3o, and having an emission spectrum with a maximum peak wavelength from 400 nm to 500 nm under an excitation of the light in a wavelength range from 350 nm to 430 nm.

A phosphor, which has less reduction in emission efficiency and is capable of keeping high luminance even when density of an electron beam for exciting the phosphor increases, is provided. As raw materials, Ca3N2 (2N), AlN (3N), Si3N4 (3N), and Eu2O3 (3N) are prepared, and each of the raw materials is weighed so that a mole ratio of each element is, for example, (Ca+Eu):Al:Si=1:1:1, and mixed, then the mixture is held and fired at 1500° C. under the inert atmosphere for three hours, and thereafter ground to produce a phosphor having a composition formula of Ca0.985SiAlN3:Eu0.015

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.

A phosphor, which has less reduction in emission efficiency and is capable of keeping high luminance even when density of an electron beam for exciting the phosphor increases, is provided. As raw materials, Ca3N2 (2N), AlN (3N), Si3N4 (3N), and Eu2O3 (3N) are prepared, and each of the raw materials is weighed so that a mole ratio of each element is, for example, (Ca+Eu):Al:Si=1:1:1, and mixed, then the mixture is held and fired at 1500° C. under the inert atmosphere for three hours, and thereafter ground to produce a phosphor having a composition formula of Ca0.985SiAlN3:Eu0.015