Tunnel junction multiple wavelength light-emitting diodes

• US 5,166,761 A
• Filed: 04/01/1991
• Issued: 11/24/1992
• Est. Priority Date: 04/01/1991
• Status: Expired due to Fees

• Current Assignee: Midwest Research Institute
• Original Assignee: Midwest Research Institute
• Inventors: Olson, Jerry M., Kurtz, Sarah R.
• Primary Examiner(s): MINTEL, WILLIAM A
• Application Number:
  US07/678,230
• Time in Patent Office: 603 Days
• Field of Search: 357/17, 357/16, 357/30 J, 357/12, 250/211 R, 250/212, 250/213 R
• US Class Current: 257/46
• CPC Class Codes: H01L 31/0687 Multiple junction or tandem solar cells
• CPC Class Codes: H01L 31/0725 Multiple junction or tandem solar cells
• CPC Class Codes: H01L 33/0016 having at least two p-n junctions
• CPC Class Codes: H01L 33/0025 comprising only AIIIBV compounds
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials

Abstract

A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect.

Claims

1. A multiple wavelength light-emitting diode having a monolithic cascade cell structure comprising:

diodes having at least two p-n junctions, wherein each of said at least two p-n junction diodes are top and bottom cells having substantially different band gaps;

electrical connector means by which said at least two p-n junctions may be collectively energized; and

a transparent tunnel p-n junction interconnecting said diodes of substantially different band gaps.

2. A diode structure as in claim 1, wherein said monolithic cascade cell structure comprises GaInP₂ /GaAs as top/bottom cells.

3. The diode of claim 1, wherein said monolithic cascade cell structure comprises AlGaInP/GaAs as top/bottom cells.

4. The diode of claim 1, wherein said diode is a two-terminal monolithic cell and said structure consists of Ga₀.5 In₀.5 P grown epitaxially upon GaAs as a bottom cell, and said transparent tunnel junction is of GaInP n⁺ /GaAs p⁺.

5. The diode of claim 1, wherein said diode is a two-terminal monolithic cell structure that consists of Ga₀.5 In₀.5 P grown epitaxially upon GaAs as a bottom cell, and said transparent tunnel junction is of GaAs n⁺ /GaAs p⁺.

6. The diode of claim 2, wherein the tunnel p-n junction is GaAs n⁺ /GaAs p⁺.

7. The diode of claim 3, wherein the tunnel p-n junction is GaAs n⁺ /GaAs p⁺.

8. The diode of claim 4, wherein the tunnel p-n junction if GaAs n⁺ /GaAs p⁺.

9. The diode of claim 1, comprising:

a top cell of n-AlInP₂ of about 0.03 μ

m thickness, n-GaInP₂ of about 0.1 μ

m thickness and p-GaInP₂ of about 0.7 μ

m thickness;

a tunnel junction of p+GaAs of between about 0.01-0.02 μ

m thickness and n+GaAs of between about 0.01-0.02 μ

m thickness; and

a bottom cell of n-AlGaAs of about 0.1 μ

m thickness, n-GaAs of about 0.1 μ

m thickness and p-GaAs of about 3.5 μ

m thickness.