The white light emitting diode comprising a light emitting component using a semiconductor as a light emitting layer and a phosphor which absorbs a part of light emitted by the light emitting component and emits light of wavelength different from that of the absorbed light, wherein the light emitting layer of the light emitting component is a nitride compound semiconductor and the phosphor contains garnet fluorescent material activated with cerium which contains at least one element selected from the group consisting of Y, Lu, Sc, La, Gd and Sm, and at least one element selected from the group consisting of Al, Ga and In and, and is subject to less deterioration of emission characteristic even when used with high luminance for a long period of time.

Light emitting device having a nitride compound semiconductor and a phosphor containing a garnet fluorescent material

The light-radiating semiconductor component has a radiation-emitting semiconductor body and a luminescence conversion element. The semiconductor body emits radiation in the ultraviolet, blue and/or green spectral region and the luminescence conversion element converts a portion of the radiation into radiation of a longer wavelength. This makes it possible to produce light-emitting diodes which radiate polychromatic light, in particular white light, with only a single light-emitting semiconductor body. A particularly preferred luminescence conversion dye is YAG:Ce.

Light-radiating semiconductor component with a luminescence conversion element

A nitride semiconductor device including a light emitting device comprises a n-type region of one or more nitride semiconductor layers having n-type conductivity, a p-type region of one or more nitride semiconductor layers having p-type conductivity and an active layer between the n-type region and the p-type region. In such devices, there is provided with a super lattice layer comprising first layers and second layers which are nitride semiconductors having a different composition respectively. The super lattice structure makes working current and voltage of the device lowered, resulting in realization of more efficient devices.

Nitride semiconductor device

The invention relates to a light source comprising a phosphor composition and a light emitting device such as an LED or a laser diode. The phosphor composition absorbs radiation having a first spectrum and emits radiation having a second spectrum and comprises at least one of: YBO3:Ce3+,Tb3+; BaMgAl?10?O17:Eu?2+, Mn2+?; (Sr,Ca,Ba)(Al,Ga)?2?S4:Eu?2+?; and Y?3?Al5O12-Ce?3+?; and at least one of: Y?2?O2S:Eu?3+,Bi3+; YVO?4:Eu3+,Bi3+; SrS:Eu2+; SrY2S4:Eu2+; CaLa?2?S4:Ce?3+?; and (Ca,Sr)S:Eu2+. The phosphor composition and the light source together can produce white light with pleasing characteristics, such as a color temperature of 3000-6500° K, a color rendering index of about 83-87, and a device luminous efficacy of about 10-20 lumens per watt.

Light emitting device with phosphor composition

A light emitting assembly comprising a solid state device coupleable with a power supply constructed and arranged to power the solid state device to emit from the solid state device a first, relatively shorter wavelength radiation, and a down-converting luminophoric medium arranged in receiving relationship to said first, relatively shorter wavelength radiation, and which in exposure to said first, relatively shorter wavelength radiation, is excited to responsively emit second, relatively longer wavelength radiation. In a specific embodiment, monochromatic blue or UV light output from a light-emitting diode is down-converted to white light by packaging the diode with fluorescent organic and/or inorganic fluorescers and phosphors in a polymeric matrix.

Solid state white light emitter and display using same

A light emitting diode comprising a first layer of gallium nitride, a second, substantially intrinsic layer of magnesium doped gallium nitride forming a junction therewith, a metallic rectifying contact to the second layer, an ohmic contact to the first layer, and means for applying a voltage across said contacts and said junctions whereby to bias the device and generate light.

D Stevenson

Papers

Gallium nitride metal-semiconductor junction light emitting diode