Ultraviolet light emitting device doped with boron

• US 9,876,143 B2
• Filed: 10/01/2014
• Issued: 01/23/2018
• Est. Priority Date: 10/01/2014
• Status: Active Grant

• Current Assignee: Rayvio Corporation
• Original Assignee: Rayvio Corporation
• Inventors: Liao, Yitao, Collins, Douglas A., Zhang, Wei
• Primary Examiner(s): Moore, Whitney T
• Assistant Examiner(s): ASSOUMAN, HERVE-LOUIS Y
• Application Number:
  US14/504,202
• Publication Number:
  US 20160099382A1
• Time in Patent Office: 1,210 Days
• Field of Search: 257 79, 257101-103
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02551 Group 12/16 materials
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/325 characterised by the doping materials

Abstract

In an example, the present invention provides a light-emitting device configured to emit electromagnetic radiation in a range of 210 to 360 nanometers. The device has a substrate member comprising a surface region. The device has a thickness of AlGaN material formed overlying the surface region and an aluminum concentration characterizing the AlGaN material having a range of 0 to 100%. The device has a boron doping concentration characterizing the AlGaN material having a range between 1e15 to 1e20 atoms/centimeter3.

Claims

1. A light emitting device configured to emit electromagnetic radiation in a range of 210 to 360 nanometers, the device comprising:

a p-type layer;

an n-type layer;

a thickness of Al_yGa_1-yN material formed epitaxially and having an aluminum concentration greater than 0% and smaller than 100%;

the thickness of the Al_yGa_1-yN material comprising a quantum well disposed between the p-type layer and n-type layer; and

wherein the Al_yGa_1-yN material comprises a boron doping concentration between 1e15 and 1e20 atoms/centimeter.

2. The device of claim 1 wherein the boron doping concentration is configured within a spatial region of the thickness of Al_yGa_1-yN material;

wherein an average lattice constant of the thickness Al_yGa_1-yN material is maintained;

wherein the thickness of Al_yGa_1-yN material is single crystal material.

3. The device of claim 1 wherein the boron doping concentration causes a local compressive strain.

4. The device of claim 1 wherein boron substitutes for nitrogen atoms within the thickness of Al_yGa_1-yN material.

5. The device of claim 1 wherein boron substitutes for either aluminum or gallium atoms within the thickness of Al_yGa_1-yN material.

6. The device of claim 1 wherein boron substitutes for both nitrogen atoms and aluminum and/or gallium atoms within the thickness of Al_yGa_1-yN material.

7. The device of claim 1 wherein boron occupies an interstitial within the thickness of Al_yGa_1-yN material.

8. The device of claim 1 wherein the boron does not form BN, BAlN, BGaN, or BAlGaN.

9. The device of claim 1 wherein the thickness of Al_yGa_1-yN material comprises an active region comprising a plurality of quantum wells.

10. The device of claim 1 further comprising a buffer region.

11. The device of claim 1 further comprising an AlGaN PN junction comprising a p-type layer and an n-type layer and an active region sandwiched between the p-type layer and the n-type layers.

12. The device of claim 1 further comprising a substrate member selected from sapphire, GaN, AlN, GaN on sapphire, AlN on sapphire, silicon, silicon carbide, and quartz.

13. The device of claim 1 wherein the aluminum concentration is between 1% and 80% and the boron doping concentration is between 1e16 and 1e18 atoms/centimeter3.

14. The device of claim 1 wherein the boron is an impurity within the thickness of Al_yGa_1-yN material.

15. The device of claim 1 wherein a light emitting efficiency of the thickness of Al_yGa_1-yN material is enhanced by introducing boron as a dopant to the thickness of Al_yGa_1-yN material.

16. The device of claim 1, wherein light emitted from the thickness of Al_yGa_1-yN material is red-shifted by at least 10 nanometers by introducing boron as a dopant to the thickness of Al_yGa_1-yN material compared to a thickness of Al_yGa_1-yN material without boron which has the same aluminum concentration.

17. The device of claim 1, wherein the thickness of Al_yGa_1-yN material is pumped by an external source comprising a light source or an electron source, the external source providing carriers into the thickness of AlGaN layer such that the thickness of Al_yGa_1-yN material emits light.

18. A light emitting device configured to emit electromagnetic radiation in a range of 210 to 360 nanometers, the device comprising:

a p-type layer, an n-type layer, and quantum well disposed between the p-type layer and n-type layer;

the quantum well comprising Al_yGa_1-yN material having aluminum composition greater than 0% and smaller than 100%;

the Al_yGa_1-yN comprising a first portion with a boron concentration between 1e15 and 1e22 atoms/centimeter and a second portion with no boron, wherein;

the first portion has a first band gap energy;

the second portion has a second band gap energy; and

the first band gap energy is within 0.5 eV of the second band gap energy.