Semiconductor light emitting device with quantum well active region of indirect bandgap semiconductor material

• US 4,365,260 A
• Filed: 12/08/1980
• Issued: 12/21/1982
• Est. Priority Date: 10/13/1978
• Status: Expired due to Term

• Current Assignee: University of Illinois
• Original Assignee: University of Illinois
• Inventors: Holonyak, Nick Jr.
• Primary Examiner(s): Edlow, Martin H.
• Application Number:
  US06/214,894
• Time in Patent Office: 743 Days
• Field of Search: 357/17, 357/16, 357/18
• US Class Current: 257/13
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/0025 comprising only AIIIBV compounds
• CPC Class Codes: H01S 5/34313 with a well layer having only As as V-compound, e.g. AlGaAs, InGaAs
• CPC Class Codes: H01S 5/3432 the whole junction comprising only (AI)GaAs

Abstract

Advantageous operation can be achieved in a semiconductor heterostructure light emitting device by utilizing a single thin active layer which exhibits quantum size effects. It has been found that performance can be degraded by employing a single quantum layer that is thinner than a certain minimum thickness, this minimum thickness being about 100 Angstroms, (the approximate carrier scattering path length). In one form of the invention, there is provided a semiconductor heterostructure device which includes first and second relatively wide bandgap semiconductor regions of opposite conductivity types. A single quantum well active layer is disposed between the first and second regions. The active layer is formed of a relatively narrow bandgap semiconductor having a thickness which is in the range of about 100 to 400 Angstroms, and is preferably about 200 Angstroms. One preferred combination of materials for the device comprises aluminum gallium arsenide for the relatively wide bandgap semiconductor regions, and gallium arsenide for the single active layer. However, other combinations of materials may be suitable, for example: indium phosphide for the relatively wide bandgap regions and indium gallium phosphide arsenide for the single active layer; or indium gallium arsenide phosphide for the relatively wide bandgap regions and gallium arsenide phosphide for the single active layer; or aluminum gallium arsenide phosphide for the confining layer and gallium arsenide phosphide for the active layer. The latter two are particularly useful as emitters in the visible portion of the spectrum. In a further form of the invention, there is disclosed a semiconductor heterostructure device wherein the active region comprises one or more quantum layers of an indirect bandgap semiconductor material, preferably germanium.

Claims

1. A semiconductor light emitter heterostructure device, comprising:

first and second relatively wide bandgap semiconductor regions of opposite conductivity types; and

an active region disposed between said first and second regions, said active region comprising a quantum well active layer of a relatively narrow bandgap indirect bandgap semiconductor material, said layer having a thickness in the range of about 100 to 400 Angstroms.

2. The device as defined by claim 1, wherein said indirect gap semiconductor material comprises germanium.

3. The device as defined by claim 1, wherein the thickness of said active layer is about 200 Angstroms.

4. The device as defined by claim 2, wherein the thickness of said active layer is about 200 Angstroms.

5. The device as defined by claim 1, wherein said first and second regions comprise Al_x Ga_1-x As.

6. The device as defined by claim 2, wherein said first and second regions comprise Al_x Ga_1-x As.

7. The device as defined by claim 3, wherein said first and second regions comprise Al_x Ga_1-x As.

8. The device as defined by claim 4, wherein said first and second regions comprise Al_x Ga_1-x As.

9. The device as defined by claim 5, wherein said active region further comprises thin layers of GaAs between the Al_x Ga_1-x As regions and the germanium layers.

10. The device as defined by claim 8, wherein said active region further comprises thin layers of GaAs between the Al_x Ga_1-x As regions and the germanium layer.

11. The device as defined by claim 1 wherein said active layer is a single active layer.

12. The device as defined by claim 2 wherein said active layer is a single active layer.