P-contact and light-emitting diode for the ultraviolet spectral range

Patent metadata

Field	Value
Publication number	US-9331246-B2
Application number	US-201013384208-A
Country	US
Kind code	B2
Filing date	Jul 16, 2010
Priority date	Jul 17, 2009
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

The present invention relates to a p-doped contact for use in a light-emitting diode for the ultraviolet spectral range, comprising a p-contact layer having a first surface for contacting a radiation zone and a second surface comprising, on the side facing away from the first surface: a) a coating, which directly contacts 5%-99.99% of the second surface of the p-contact layer and contains or consists of a material having a maximum reflectivity of at least 60% for light with a wavelength of 200 nm to 400 nm; b) a plurality of p-injectors, which are disposed directly on the second surface of the p-contact layer.

First claim

The invention claimed is:

1. A p-doped contact for use in a light-emitting diode for the ultraviolet spectral range, the p-doped contact comprising:
a p-contact layer comprising AlGaN and having a first surface for contacting a radiation zone, and a second surface opposite the first surface;
a coating covering 75%-96% of the second surface of the p-contact layer, the coating comprising a material having a maximum reflectivity of at least 60% for light in a UV range with a wavelength of 200 nm to 400 nm; and
a plurality of p-injectors arranged on the second surface of the p-contact layer, the p-injectors comprising a p-injector metal layer and at least one other p-injector layer in direct contact with the p-injector metal layer, the at least one other p-injector layer comprising p-GaN or p-(In)GaN.

2. The p-doped contact according to claim 1 , wherein the coating is electrically conductive.

3. The p-doped contact according to claim 1 , wherein the coating further covers one or more p-injectors of the p-doped contact.

4. The p-doped contact according to claim 1 , wherein the coating comprises Al.

5. The p-doped contact according to claim 1 , wherein the p-injectors comprise at least one p-injector metal layer, which enables an ohmic connection of the p-contact layer with a current source.

6. The p-doped contact according to claim 1 , wherein the p-injectors comprise a p-injector metal layer comprising at least one of Au, Ni, Pd, Pt, Rh, Ti, Ni/Au, Pd/Ti/Au, Pd/Pt/Au or Pt/Ti/Au.

7. The p-doped contact according to claim 1 , wherein the p-contact layer comprises one or more different semiconductor layers.

8. The p-doped contact according to claim 1 , wherein the p-contact layer further comprises a semiconductor layer, which forms the second surface of the p-contact layer and to which the p-injectors are applied, comprising p-doped AlGaN.

9. The p-doped contact according to claim 1 , wherein the p-injectors have a maximum width D of 10 nm to 50 μm.

10. The p-doped contact according to claim 1 , wherein the p-injectors are spaced a distance A of 20 nm to 20 μm away from their respectively adjacent p-injectors.

11. The p-doped contact according to claim 1 , wherein distances A between the p-injectors and their respective adjacent p-injectors are identical for all p-injectors.

12. The p-doped contact according to claim 1 , wherein the p-injectors have a maximum width D, the p-injectors are spaced at a distance A, and D and A are selected in such a way that a ratio D to A is between 1:1 and 1:4.

13. The p-doped contact according to claim 1 , wherein the p-injectors are arranged in a uniform pattern on the second surface of the p-contact layer.

14. A light-emitting diode comprising a radiation zone, which is arranged between an n-doped contact and the p-doped contact according to claim 1 .

15. The light-emitting diode according to claim 14 , wherein the light-emitting diode is configured to emit light in the UV range of 200 nm to 400 nm.

16. The light-emitting diode according to claim 15 , wherein the light emitting diode is configured to emit light in at least one of a UV-A range, a UV-B range, or a UV-C range.

17. The p-doped contact according to claim 1 , wherein the at least one other p-injector layer consists of p-GaN or p-(In)GaN.

18. The p-doped contact according to claim 1 , wherein the at least one other p-injector layer has a cross section that substantially matches that of the p-injector metal layer in a plane parallel to a surface of the p-contact layer.

Assignees

• Kneissl Michael
• Weyers Markus
• Einfeldt Sven
• Rodriguez Hernan
• Forschungsverbund Berlin Ev

Inventors

• Kneissl Michael
• Weyers Markus
• Einfeldt Sven
• Rodriguez Hernan

Classifications

• H10H20/841

  Reflective coatings, e.g. dielectric Bragg reflectors · CPC title

• H10H20/832

  characterised by their material · CPC title

• H10H20/8316 Primary

  Multi-layer electrodes comprising at least one discontinuous layer · CPC title

• H01L33/46

  Electricity · mapped topic

• H01L33/387 Primary

  Electricity · mapped topic