Luminescent diode chip with luminescence conversion element and angular filter element

• US 8,405,104 B2
• Filed: 05/21/2008
• Issued: 03/26/2013
• Est. Priority Date: 05/30/2007
• Status: Active Grant

• Current Assignee: OSRAM OLED GMBH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Streubel, Klaus, Wirth, Ralph
• Primary Examiner(s): Nguyen, Ha Tran T
• Assistant Examiner(s): Tran, Thanh Y
• Application Number:
  US12/595,356
• Publication Number:
  US 20100084678A1
• Time in Patent Office: 1,770 Days
• Field of Search: 257/98, 257/99, 257/100, 257/89, 257/88, 257/79, 257/80, 257/95, 257/436, 438/22, 438/25, 438/26, 438/27, 438/28, 438/29, 438/24, 438/46, 438/47, 438/48, 438/35, 438/34
• US Class Current: 257/98
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/50 Wavelength conversion elements

Abstract

A luminescent diode chip includes a semiconductor body, which produces radiation of a first wavelength. A luminescence conversion element produces radiation of a second wavelength from the radiation of the first wavelength. An angular filter element reflects radiation that impinges on the angular filter element at a specific angle in relation to a main direction of emission back in the direction of the semiconductor body.

Claims

1. A luminescent diode chip comprising:

a semiconductor body that produces radiation of a first wavelength;

a luminescence conversion element that produces radiation of a second wavelength from the radiation of the first wavelength; and

an angular filter element that reflects radiation that impinges on the angular filter element in a predetermined angular range in relation to a main direction of emission at least partially back in the direction of the semiconductor body, wherein, at the first wavelength, the angular filter element has a greater intensity reflection factor for smaller angles of incidence than larger angles of incidence, and wherein, at the first wavelength, the angular filter element has a lower intensity transmission factor for smaller angles of incidence than larger angles of incidence.

2. The luminescent diode chip according to claim 1, wherein the angular filter element reflects at least part of the radiation of the first wavelength back in such a way that an overall radiation emitted by the luminescent diode chip has a uniform color location independent of angle.

3. The luminescent diode chip according to claim 2, wherein the overall radiation emitted by the luminescent diode chip has radiation components of the first wavelength and of the second wavelength.

4. The luminescent diode chip according to claim 1, wherein the angular filter element reflects radiation of the first wavelength back in the direction of the semiconductor body.

5. The luminescent diode chip according to claim 1, wherein the angular filter element is arranged on the semiconductor body and the luminescence conversion element is arranged downstream of the angular filter element in the main direction of emission.

6. The luminescent diode chip according to claim 5, wherein the luminescence conversion element comprises a luminescence conversion layer applied to the angular filter element.

7. The luminescent diode chip according to claim 6, wherein the luminescence conversion element comprises a sealing, which contains a luminescence conversion material and in which the angular filter element and the semiconductor body are embedded.

8. The luminescent diode chip according to claim 1, wherein the angular filter element reflects radiation of the second wavelength in the direction of a coupling-out side of the luminescent diode chip.

9. The luminescent diode chip according to claim 1, wherein the luminescence conversion element is arranged on the semiconductor body and the angular filter element is arranged downstream of the luminescence conversion element in the main direction of emission.

10. The luminescent diode chip according to claim 9, wherein the luminescence conversion element comprises a luminescence conversion layer applied to the semiconductor body.

11. The luminescent diode chip according to claim 1, wherein the angular filter element comprises a dielectric filter.

12. The luminescent diode chip according to claim 1, wherein the angular filter element comprises a stack of layers made up of at least two layers with different refractive indexes.

13. The luminescent diode chip according to claim 12, wherein the stack of layers comprises a first layer that comprises silicon oxide and a second layer that comprises silicon nitride.

14. The luminescent diode chip according to claim 1, wherein the angular filter element comprises a Bragg reflector.

15. The luminescent diode chip according to claim 1, wherein the angular filter element has structural elements.

16. The luminescent diode chip according to claim 15, wherein the structural elements are formed in a conical, pyramidal or prismatic manner.

17. The luminescent diode chip according to claim 1, wherein the radiation reflected back in the direction of the semiconductor body has a wavelength that is at a long-wave flank of a stop band of the angular filter element.

18. The luminescent diode chip according to claim 1, wherein the radiation reflected back in the direction of the semiconductor body has a wavelength that is within a stop band of the angular filter element.

19. The luminescent diode chip according to claim 1, wherein the semiconductor body comprises a thin-film semiconductor body.

20. The luminescent diode chip according to claim 1, further comprising a reflective layer arranged on a side of the semiconductor body that is facing away from the angular filter element.

21. A luminescent diode component comprising a luminescent diode chip according to claim 1, the luminescent diode chip being arranged in a package.

22. The luminescent diode chip according to claim 1, wherein, at the first wavelength, the intensity transmission factor of the angular filter element varies over the greater angles of incidence.

23. The luminescent diode chip according to claim 22, wherein the intensity transmission factor of the angular filter element has more than one maximum value over the greater angles of incidence.

24. A luminescent diode chip comprising:

a semiconductor body that produces radiation of a first wavelength;

a luminescence conversion element that produces radiation of a second wavelength from the radiation of the first wavelength; and

an angular filter element that reflects radiation that impinges on the angular filter element in a predetermined angular range in relation to a main direction of emission at least partially back in the direction of the semiconductor body, wherein the angular filter element reflects at least part of the radiation of the first wavelength back in such a way that an overall radiation emitted by the luminescent diode chip has a uniform color location independent of angle, wherein, at the first wavelength, the angular filter element has a lower intensity transmission factor for smaller angles of incidence than larger angles of incidence.

25. The luminescent diode chip according to claim 24, wherein the radiation of the first wavelength that leavers the luminescent diode chip is attenuated by means of the reflection of the angular filter element.

26. The luminescent diode chip according to claim 24, wherein the angular filter element comprises a stack of layers made up of at least two layers with different refractive indices.

27. A luminescent diode chip comprising:

a semiconductor body that produces radiation of a first wavelength;

a luminescence conversion element that produces radiation of a second wavelength from the radiation of the first wavelength; and

an angular filter element that reflects radiation that impinges on the angular filter element in a predetermined angular range in relation to a main direction of emission at least partially back in the direction of the semiconductor body, wherein, at the first wavelength, the angular filter element has a greater intensity reflection factor over a first angular range than over a second angular range, wherein the first angular range is located between the main direction of emission and the second angular range, wherein the first angular range is a range of angles from the main direction of emission less than 30°

, and wherein the second angular range is a range of angles from the main direction of emission of 30°

to about 60°

.

28. The luminescent diode chip according to claim 27, wherein, at the first wavelength, the angular filter element has a greater intensity reflection factor over a third angular range than the second angular range, and wherein the third angular range is a range of angles from the main direction of emission greater than 70°

.

29. A luminescent diode chip comprising:

a semiconductor body that produces radiation of a first wavelength;

wherein, at the first wavelength, the angular filter element has a lower intensity transmission factor over the first angular range than over the second angular range.

30. The luminescent diode chip according to claim 29, wherein, at the first wavelength, the intensity transmission factor of the angular filter element varies over the second angular range.

31. The luminescent diode chip according to claim 30, wherein the intensity transmission factor of the angular filer element has more than one maximum value over the second angular range.