Light emitting device with blue light led and phosphor components

• US 7,215,074 B2
• Filed: 08/23/2005
• Issued: 05/08/2007
• Est. Priority Date: 07/29/1996
• Status: Expired due to Fees

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Shimizu, Yoshinori, Moriguchi, Toshio, Sakano, Kensho, Noguchi, Yasunobu
• Primary Examiner(s): WILLIAMS, JOSEPH L
• Application Number:
  US11/208,729
• Publication Number:
  US 20050280357A1
• Time in Patent Office: 623 Days
• Field of Search: 313/512, 313/486, 313/489, 313/498, 313/501, 313/502, 313/493, 313/503, 313/506, 257/103, 428/690
• US Class Current: 313/503
• CPC Class Codes: C09K 11/7767 Chalcogenides
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: G02B 6/0023 provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• CPC Class Codes: G02B 6/0025 Diffusing sheet or layer; Prismatic sheet or layer
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: H01J 29/20 characterised by the luminescent material
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/45169 Platinum (Pt) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01021 : Scandium [Sc]
• CPC Class Codes: H01L 2924/01067 : Holmium [Ho]
• CPC Class Codes: H01L 2924/01068 : Erbium [Er]
• CPC Class Codes: H01L 2924/12036 : PN diode
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/15747 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/20751 : larger or equal to 10 microns less than 20 microns
• CPC Class Codes: H01L 2924/20752 : larger or equal to 20 microns less than 30 microns
• CPC Class Codes: H01L 2924/20753 : larger or equal to 30 microns less than 40 microns
• CPC Class Codes: H01L 2924/20754 : larger or equal to 40 microns less than 50 microns
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 2933/0091 : Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/50 : Wavelength conversion elements
• CPC Class Codes: H01L 33/501 : characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/504 : Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/56 : Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H05B 33/14 : characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: Y02B 20/00 : Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A light emitting device accoridng to an emboidment includes a first light emitting component including a semiconductor layer that is doped with an impurity, the first light emitting component emitting light in a blue region; a second light emitting component including a light-emitting semiconductor layer that emits light in a red region; and a phosphor capable of absorbing a part of the light emitted by the first light emitting component, and emitting light in a yellow region. The phosphor is not substantially excited by the light from the second light emitting component. The light emitting device is capable of emitting red/white light.

Claims

1. A light emitting device comprising:

a first light emitting component including a semiconductor layer that is doped with an impurity, said first light emitting component emitting light in a blue region;

a second light emitting component including a light-emitting semiconductor layer that emits light in a red region; and

a phosphor capable of absorbing a part of the light emitted by said first light emitting component, and emitting light in a yellow region,

wherein said phosphor is not substantially excited by the light from said second light emitting component, and

wherein said light emitting device is capable of emitting red and/or white light.

2. The light emitting device according to claim 1, wherein the light-emitting semiconductor layer of said first light emitting component includes a nitride compound semiconductor.

3. The light emitting device according to claim 1, wherein the light-emitting semiconductor layer of said second light emitting component includes a semiconductor selected from a group consisting of gallium phosphate, gallium aluminum arsenide, gallium arsenic phosphate, and indium aluminum phosphate.

4. The light emitting device according to claim 1, wherein said phosphor contains a garnet fluorescent material comprising 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 being activated with cerium.

5. The light emitting device according to claim 1, wherein a main emission peak of said first light emitting component is set within the range from 400 nm to 530 nm and a main emission wavelength of said phosphor is set to be longer than the main emission peak of said first light emitting component.