1175 results about "Emission efficiency" patented technology

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.

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 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.

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.

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