Quantum well device with control of spontaneous photon emission, and method of manufacturing same

• US 5,089,860 A
• Filed: 06/25/1990
• Issued: 02/18/1992
• Est. Priority Date: 06/25/1990
• Status: Expired due to Term

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Rogers, Thomas J., Deppe, Dennis G.
• Primary Examiner(s): James, Andrew J.
• Assistant Examiner(s): Crane, Sara W.
• Application Number:
  US07/543,477
• Time in Patent Office: 603 Days
• Field of Search: 357/16, 357/17, 372/47, 372/43, 372/49
• US Class Current: 257/13
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01S 5/18358 containing spacer layers to adjust the phase of the light wave in the cavity
• CPC Class Codes: H01S 5/18361 Structure of the reflectors, e.g. hybrid mirrors

Abstract

In the present invention, spontaneous photon emission intensity in a semiconductor quantum well is strongly influenced by a highly reflecting interface, with the quantum well to interface spacing being less than the optical emission wavelength of the quantum well. An enhancement/inhibition ratio on the order of 10 is possible according to the present invention using a single reflector, and enhancement/inhibition ratios on the order of 1000 are possible when two reflectors are used in the quantum well light-emitting diode structures. In addition, according to the present invention, the gain, directionality, and efficiency of a vertical cavity surface-emitting laser can also be greatly improved. A method of making a device according to the present invention is also presented.

Claims

1. A light-emitting semiconductor device with improved spontaneous photon emission, comprising:

a quantum well capable of emitting light of an optical emission wavelength, a thickness of said quantum well being much less than said optical wavelength; and

a single reflector spaced from said quantum well a distance substantially equal to one-fourth said optical emission wavelength, said reflector having means for causing phase shift of said emission wavelength, to control spontaneous photon emission of said quantum well.

6. The device of claim 1, wherein the quantum well is at an anti-node of said electromagnet vacuum field.

7. The device of claim 1, wherein the quantum well is at a node of said electromagnetic vacuum field.

8. The device of claim 1, further comprising:

a material of first conductivity adjacent a first side of said quantum well intermediate said reflector and said quantum well; and

a material of a second conductivity adjacent a second side of said quantum well.

2. A light-emitting semiconductor device with improved spontaneous photon emission, comprising:

a quantum well capable of emitting light of an optical emission wavelength, a thickness of said quantum well being much less than said optical wavelength;

a first reflector spaced from said quantum well a distance substantially equal to said optical emission wavelength;

a second reflector spaced from said quantum well a distance substantially equal to one-fourth said optical emission wavelength, whereby said quantum well is intermediate said first and second reflectors, and wherein a reflectivity of said first reflector is less than a reflectivity of said second reflector; and

said second reflector having means for causing phase shift of said emission wavelength to control spontaneous photon emission of said quantum well.

3. The device of claim 2, wherein said reflectivity of said first reflector is much less than said reflectivity of said second reflector.

4. The device of claim 2, wherein said quantum well is placed at an anti-node of said electromagnetic vacuum field within said semiconductor device.

5. The device of claim 2, further comprising:

a material of a first conductivity intermediate said first reflector and said quantum well; and

a material of a second conductivity intermediate said second reflector and said quantum well.

9. The device of claim 2, wherein said quantum well is at a node of an electromagnetic vacuum field within said semiconductor device.

10. The device of claim 2, wherein said quantum well is at an anti-node of an electromagnetic vacuum field within said semiconductor device.

11. The device of claim 2, said second reflector comprising materials of alternating values of refractive index.

12. A light-emitting semiconductor device with improved spontaneous photon emission, comprising:

a quantum well capable of emitting light of an optical emission wavelength, a thickness of said quantum well being much less than said optical wavelength; and

a single reflector having a reflectivity of at most 0.998 and spaced from said quantum well a distance substantially equal to one-fourth said optical emission wavelength;

said quantum well being placed at an anti-node or node of an electromagnetic vacuum field within said semiconductor device.

13. The device of claim 12, further comprising:

a material of first conductivity adjacent a first side of said quantum well intermediate said reflector and said quantum well; and

a material of a second conductivity adjacent a second side of said quantum well.

14. A light-emitting semiconductor device with improved spontaneous photon emission, comprising:

a quantum well capable of emitting light of an optical emission wavelength, a thickness of said quantum well being much less than said optical wavelength;

a first reflecting interface spaced from said quantum well a distance substantially equal to said optical emission wavelength;

a second reflecting interface including a plurality of material layers of alternating values of refractive index, said plurality of layers having one layer arranged nearest said quantum well and spaced from said quantum well a distance substantially equal to one-fourth said optical emission wavelength, whereby said quantum well is intermediate said first and second reflecting interfaces, and wherein a reflectivity of said first reflecting interface is less than a reflectivity of said second reflecting interface; and

said quantum well being at an anti-node or node of an electromagnetic vacuum field within said semiconductor device.