An organometallic complex which can be provided at low cost and which emits blue phosphorescence is provided. An organometallic complex in which nitrogen at the 1-position of a 5-aryl-4H-1,2,4-triazole derivative is coordinated to a Group 9 metal or a Group 10 metal, the aryl group is bonded to the Group 9 metal or the Group 10 metal, and the 5-aryl-4H-1,2,4-triazole derivative is a 3-aryl-5,6,7,8-tetrahydro-4H-[1,2,4]triazolo[4,3-a]pyridine derivative is provided. The organometallic complex emits green to blue phosphorescence and is also advantageous in terms of cost.

An organometallic complex which can be provided at low cost and which emits blue phosphorescence is provided. An organometallic complex in which nitrogen at the 1-position of a 5-aryl-4H-1,2,4-triazole derivative is coordinated to a Group 9 metal or a Group 10 metal, the aryl group is bonded to the Group 9 metal or the Group 10 metal, and the 5-aryl-4H-1,2,4-triazole derivative is a 3-aryl-5,6,7,8-tetrahydro-4H-[1,2,4]triazolo[4,3-a]pyridine derivative is provided. The organometallic complex emits green to blue phosphorescence and is also advantageous in terms of cost.

A light-emitting device includes a light-emitting element for emitting primary light, and a wavelength conversion unit for absorbing part of the primary light and emitting secondary light having a wavelength longer than that of the primary light, wherein the wavelength conversion unit includes plural kinds of phosphors having light absorption characteristics different from each other, and then at least one kind of phosphor among the plural kinds of phosphors has an absorption characteristic that can absorb the secondary light emitted from at least another kind of phosphor among the plural kinds of phosphors.

A light-emitting device includes a light-emitting element for emitting primary light, and a wavelength conversion unit for absorbing part of the primary light and emitting secondary light having a wavelength longer than that of the primary light, wherein the wavelength conversion unit includes plural kinds of phosphors having light absorption characteristics different from each other, and then at least one kind of phosphor among the plural kinds of phosphors has an absorption characteristic that can absorb the secondary light emitted from at least another kind of phosphor among the plural kinds of phosphors.

A core-shell fluorescent material and a light source device using the same are disclosed. The core-shell fluorescent material includes a core and a shell for generating an emitting light with wavelength within 520 and 800 nm after absorbing an exciting light with wavelength within 370 and 500 nm. The core may include yellow, green or red fluorescent powder, and the shell includes manganese (IV)-doped fluoride compound. The light source device generally includes the core-shell fluorescent material, a radiation source, leads and a package. The leads provide current to the radiation source and cause the radiation source to emit radiation. The core-shell fluorescent material is coated on the package for receiving the radiation so as to generate a high quality emission served as the desired light source for the field of lighting and displaying.

A core-shell fluorescent material and a light source device using the same are disclosed. The core-shell fluorescent material includes a core and a shell for generating an emitting light with wavelength within 520 and 800 nm after absorbing an exciting light with wavelength within 370 and 500 nm. The core may include yellow, green or red fluorescent powder, and the shell includes manganese (IV)-doped fluoride compound. The light source device generally includes the core-shell fluorescent material, a radiation source, leads and a package. The leads provide current to the radiation source and cause the radiation source to emit radiation. The core-shell fluorescent material is coated on the package for receiving the radiation so as to generate a high quality emission served as the desired light source for the field of lighting and displaying.

A material for organic electroluminescence devices comprising a compound having a specific structure and an organic electroluminescence device comprising an organic thin film layer which comprises one layer or a plurality of layers comprising at least a light emitting layer and disposed between a cathode and an anode, wherein at least one layer in the organic thin film layer comprises the material for organic electroluminescence devices, are provided. The material provides the organic electroluminescence device exhibiting a great efficiency of light emission, having no defect pixels, exhibiting excellent heat resistance and having a long life.

The purpose of the present invention is to provide a scintillator for a charged particle beam device and a charged particle beam device which achieve both an increase in emission intensity and a reduction in afterglow intensity. This scintillator for a charged particle beam device is characterized by comprising a substrate (13), a buffer layer (14) formed on a surface of the substrate (13), a stack (12) of a light emitting layer (15) and a barrier layer (16) formed on a surface of the buffer layer (14), and a conductive layer (17) formed on a surface of the stack (12) and by being configured such that the light emitting layer (15) contains InGaN, the barrier layer (16) contains GaN, and the ratio b/a of the thickness b of the barrier layer (16) to the thickness a of the light emitting layer (15) is 11 to 25.

A light guide assembly, a total reflective display device and a method for manufacturing a light guide assembly are provided in the embodiments of the disclosure, the light guide assembly including: a first transparent adhesion layer, having a first profile formed thereon; a second transparent adhesion layer adhered to the first transparent adhesion layer and formed with a second profile corresponding to the first profile on a side of the second transparent adhesion layer adhered to the first transparent adhesion layer, the first profile and the second profile being formed to be in positive fit with each other and configured to incur light refraction at an interface therebetween of light rays being incident upon the first transparent adhesion layer from the second transparent adhesion layer to decrease an incident angle of the light rays; and a light guide panel, arranged on a side of the second transparent adhesion layer facing away from the first transparent adhesion layer.

Provided are an organic electroluminescence device, which shows high luminous efficiency, is free of any pixel defect, and has a long lifetime, and a material for an organic electroluminescence device for realizing the device. The material for an organic electroluminescence device is a compound having a n-conjugated heteroacene skeleton crosslinked with a carbon atom, nitrogen atom, oxygen atom, or sulfur atom. The organic electroluminescence device has one or more organic thin film layers including a light emitting layer between a cathode and an anode, and at least one layer of the organic thin film layers contains the material for an organic electroluminescence device.