4415 results about "Quantum efficiency" patented technology

A polymer light emitting material, wherein the material has a light emitting mechanism based on transition from an excited triplet state to a ground state or transition through an excited triplet state to a ground state of an electron energy level, and the material comprises a nonionic light emitting part which constitutes a part of the polymer or is bound to the polymer. The polymer light emitting material exhibits high light emission efficiency above 5%, which is the limit of external quantum efficiency of fluorescence and can be designed so as to have a large area and hence are suitable for mass production of organic light emitting devices.

Matrixes doped with semiconductor nanocrystals are provided. In certain embodiments, the semiconductor nanocrystals have a size and composition such that they absorb or emit light at particular wavelengths. The nanocrystals can comprise ligands that allow for mixing with various matrix materials, including polymers, such that a minimal portion of light is scattered by the matrixes. The matrixes of the present invention can also be utilized in refractive index matching applications. In other embodiments, semiconductor nanocrystals are embedded within matrixes to form a nanocrystal density gradient, thereby creating an effective refractive index gradient. The matrixes of the present invention can also be used as filters and antireflective coatings on optical devices and as down-converting layers. Processes for producing matrixes comprising semiconductor nanocrystals are also provided. Nanostructures having high quantum efficiency, small size, and / or a narrow size distribution are also described, as are methods of producing indium phosphide nanostructures and core-shell nanostructures with Group II-VI shells.

The present invention provides: an organic EL element exhibiting high luminance, a high external quantum efficiency and a long high temperature driving life at 50° C.; an illuminator and a display device employing the organic EL element; and a material preferably used for the organic EL element.

A high external quantum efficiency is stably secured in a semiconductor light emitting device. At least one recess and / or protruding portion is created on the surface portion of a substrate for scattering or diffracting light generated in a light emitting region. The recess and / or protruding portion has a shape that prevents crystal defects from occurring in semiconductor layers.

Matrixes doped with semiconductor nanocrystals are provided. In certain embodiments, the semiconductor nanocrystals have a size and composition such that they absorb or emit light at particular wavelengths. The nanocrystals can comprise ligands that allow for mixing with various matrix materials, including polymers, such that a minimal portion of light is scattered by the matrixes. The matrixes are optionally formed from the ligands. The matrixes of the present invention can also be utilized in refractive index matching applications. In other embodiments, semiconductor nanocrystals are embedded within matrixes to form a nanocrystal density gradient, thereby creating an effective refractive index gradient. The matrixes of the present invention can also be used as filters and antireflective coatings on optical devices and as down-converting layers. Processes for producing matrixes comprising semiconductor nanocrystals are also provided. Nanostructures having high quantum efficiency, small size, and / or a narrow size distribution are also described, as are methods of producing indium phosphide nanostructures and core-shell nanostructures with Group II-VI shells.

The invention relates to a quantum dot. The quantum dot comprises a core including a semiconductor material Y selected from the group consisting of Si and Ge. The quantum dot also comprises a shell surrounding the core. The quantum dot is substantially defect free such that the quantum dot exhibits photoluminescence with a quantum efficiency that is greater than 10 percent.