There is provided white light illumination system including a radiation source, a first luminescent material having a peak emission wavelength of about 575 to about 620 nm, a second luminescent material having a peak emission wavelength of about 495 to about 550 nm, which is different from the first luminescent material and a third luminescent material having a peak emission wavelength of about 420 to about 480 nm, which is different from the first and second luminescent materials. The LED may be a UV LED and the luminescent materials may be a blend of three or four phosphors. The first phosphor may be an orange emitting Eu2+, Mn2+ activated strontiumpyrophosphate, Sr2P2O7:Eu2+, Mn2+. The second phosphor may be a blue-green emitting Eu2+ activated bariumsilicate, (Ba,Sr,Ca)2SiO4:Eu2+. The third phosphor may be a blue emitting SECA phosphor, (Sr,Ba,Ca)5(PO4)3Cl:Eu2+. Optionally, the fourth phosphor may be a red emitting Mn4+ activated magnesium fluorogermanate, 3.5MgO*0.5MgF2*GeO2:Mn4+. A human observer perceives the combination of the orange, blue-green, blue and / or red phosphor emissions as white light.
A blue-emitting phosphor is optimized by controlling mole fractions typically of Mg and Si in Sr3-eMgbSi2cO8d:Eue or by further including an optimal amount of at least one additional component such as Ba or Ca. The resulting phosphor exhibits a higher brightness and a higher color purity upon excitation by ultraviolet light emitted as a result of discharge of xenon gas. The optimized phosphor is incorporated into light emitting devices such as lamps and PDPs, and further into display devices.
An LED lamp or bulb is disclosed that comprises a light source, a heat sink structure and an optical cavity. The optical cavity comprises a phosphor carrier having a conversions material and arranged over an opening to the cavity. The phosphor carrier comprises a thermally conductive transparent material and is thermally coupled to the heat sink structure. An LED based light source is mounted in the optical cavity remote to the phosphor carrier with light from the light source passing through the phosphor carrier. A diffuser dome is included that is mounted over the optical cavity, with light from the optical cavity passing through the diffuser dome. The diffuser dome can disperse the light passing through it into the desired emission pattern, such as omnidirection. In one embodiment, the light source can be blue emitting LED and the phosphor carrier can include a yellow phosphor, with the LED lamp or bulb emitting a white light combination of LED and phosphor light.
The present invention is directed to a full color organic electroluminescent device which comprises a substrate; a first electrode formed on the substrate; an organic emitting layer formed on the first electrode, and having a red-emitting layer, a green-emitting layer and a blue-emitting layer, respectively patterned in a red pixel region, a green pixel region and a blue pixel region, and having the red and green-emitting layer consisting of a phosphorescent material and the blue-emitting layer consisting of a fluorescent material; a hole blocking layer formed on the organic emitting layer as a common layer; and a second electrode formed on the hole blocking layer, so that the full color organic electroluminescent device having enhanced lifetime and luminous efficiency characteristics can be provided.
The present invention relates to a novel diamine derivative, a method for preparation thereof, and an organic electronic device using the same. The diamine derivative according to the present invention can serve as a hole injecting, hole transporting, electron injecting, electron transporting, or light emitting material in an organic electronic device including an organic light emitting device. Particularly, it can be used as a light emitting material as used alone, and also serve as a light emitting host, or a light emitting dopant, in particular, a blue light emitting dopant. The organic electronic device according to the present invention exhibits excellent characteristics in terms of efficiency, drive voltage, life time, and stability.