WAVELENGTH CONVERTING SUBSTANCE, WAVELENGTH CONVERTING GEL AND LIGHT EMITTING DEVICE

• US 20140131751A1
• Filed: 05/29/2013
• Published: 05/15/2014
• Est. Priority Date: 11/12/2012
• Status: Active Grant

• Current Assignee: Genesis Photonics Inc.
• Original Assignee: Genesis Photonics Inc.
• Inventors: Li, Yun-Li, Li, Yu-Chu, Chen, Cheng-Yen
• Granted Patent: US 9,299,894 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: C09K 11/706 Aluminates; Silicates
• CPC Class Codes: G02F 1/3556 Semiconductor materials, e.g. quantum wells
• 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: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A wavelength converting substance is made of semiconductor material. The wavelength converting substance is suitable for absorbing an exciting light with the wavelength range falling between 300 nanometers and 490 nanometers and converting the exciting light to an emitted light with wavelength range falling between 450 nanometers and 750 nanometers.

Claims

1. A wavelength converting substance made of a semiconductor material, the wavelength converting substance being suitable for absorbing an exciting light with wavelength range falling between 300 nanometers and 490 nanometers, and the exciting light being converted to an emitted light with wavelength range falling between 450 nanometers and 750 nanometers.

2. The wavelength converting substance as recited in claim 1, wherein a chemical formula of the wavelength converting substance is (Al_xGa_1-x)_yIn_1-yP, wherein 0≦

x≦

0.7 and 0≦

y≦

0.7.

3. The wavelength converting substance as recited in claim 1, wherein the wavelength range of the emitted light falls between 570 nanometers and 750 nanometers.

4. A wavelength converting gel comprising:

an encapsulating glue; and

a plurality of wavelength converting substances made of a semiconductor material and dispersed within the encapsulating glue, each wavelength converting substance being suitable for absorbing an exciting light with wavelength range falling between 300 nanometers and 490 nanometers, and the exciting light being converted to an emitted light with wavelength range falling between 450 nanometers and 750 nanometers.

5. The wavelength converting gel as recited in claim 4 further comprising a plurality of yellow fluorescent materials dispersed within the encapsulating glue, wherein a wavelength range of an emitted light of each yellow fluorescent material falls between 500 nanometers and 570 nanometers.

6. The wavelength converting gel as recited in claim 5, wherein each yellow fluorescent material comprises yttrium aluminum garnet fluorescent powders, terbium aluminum garnet fluorescent powders, lutetium aluminum garnet fluorescent powders, silicate fluorescent powders or nitride fluorescent powders.

7. The wavelength converting gel as recited in claim 4, wherein a particle size of each wavelength converting substance is ranged from 1 micron to 100 microns.

8. The wavelength converting gel as recited in claim 4, wherein a chemical formula of each wavelength converting substance is (Al_xGa_1-x)_yIn_1-yP, wherein 0≦

x≦

0.7 and 0≦

y≦

0.7.

9. A light emitting device comprising:

a light emitting element, the light emitting element emitting an exciting light with wavelength range falling between 300 nanometers and 490 nanometers; and

at least one wavelength converting substance disposed on the light emitting element, the wavelength converting substance made of a semiconductor material, wherein each wavelength converting substance absorbs the exciting light and converts the exciting light to an emitted light with wavelength range falling between 450 nanometers and 750 nanometers.

10. The light emitting device as recited in claim 9, wherein the wavelength converting substance is in a powder form, and a particle size of the wavelength converting substance is ranged from 1 micron to 100 microns.

11. The light emitting device as recited in claim 9, wherein the light emitting element comprises a substrate, a first-type semiconductor layer, a second-type semiconductor layer, a light emitting layer, a first electrode and a second electrode, the first-type semiconductor layer, the light emitting layer and the second-type semiconductor layer are sequentially stacked on an upper surface of the substrate, the first electrode and the second electrode are respectively disposed on the first-type semiconductor layer and the second-type semiconductor layer, the wavelength converting substance covers a lower surface of the substrate opposite to the upper surface, and the wavelength converting substance is a sheet wavelength converting substance.

12. The light emitting device as recited in claim 10 further comprising a sealant, and the at least one wavelength converting substance comprising a plurality of wavelength converting substances, wherein the sealant covers the light emitting element and the wavelength converting substances.

13. The light emitting device as recited in claim 12 further comprising a plurality of yellow fluorescent materials dispersed within the sealant, wherein each yellow fluorescent material is excited by the exciting light to emit a fluorescence with wavelength range falling between 500 nanometers and 570 nanometers.

14. The light emitting device as recited in claim 9, wherein the light emitting element is a gallium nitride based light emitting diode chip.

15. The light emitting device as recited in claim 10 further comprising an encapsulating glue, and the at least one wavelength converting substance comprising a plurality of wavelength converting substances, wherein the encapsulating glue mixes with the wavelength converting substances so as to define a wavelength converting gel.

16. The light emitting device as recited in claim 15 further comprising a transparent layer covering the light emitting element and disposed between the wavelength converting gel and the light emitting element.

17. The light emitting device as recited in claim 16, wherein a refractive index of the transparent layer is ranged from 1.0 to 2.0, and the transparent layer is an air layer or a film layer made of inorganic material.

18. The light emitting device as recited in claim 16 further comprising a yellow fluorescent adhesive layer disposed between the transparent layer and the wavelength converting gel, wherein the yellow fluorescent adhesive layer is excited by the exciting light to emit a fluorescence with wavelength range falling between 500 nanometers and 570 nanometers.

19. The light emitting device as recited in claim 9, wherein a chemical formula of the wavelength converting substance is (Al_xGa_1-x)_yIn_1-yP, wherein 0≦

x≦

0.7 and 0≦

y≦

0.7.