Aperiodic dielectric multilayer stack

• US 20050266218A1
• Filed: 06/01/2004
• Published: 12/01/2005
• Est. Priority Date: 06/01/2004
• Status: Active Grant

• Current Assignee: The Trustees of Princeton University (Princeton University)
• Original Assignee: The Trustees of Princeton University (Princeton University)
• Inventors: Forrest, Stephen, Peumans, Peter
• Granted Patent: US 7,196,835 B2
• Time in Patent Office: Days
• US Class Current: 428/216
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick

Abstract

A structure is provided that includes an aperiodic dielectric stack. The structure may include a substrate, a device disposed over the substrate, and a first dielectric stack disposed between the substrate and the device. The first dielectric stack includes a plurality of layers comprising a first dielectric material, wherein at least two of the layers comprising a first dielectric material have substantially different thicknesses, as well as a plurality of layers comprising a second dielectric material. The average outcoupling efficiency into air of the device over a bandwidth of at least 300 nm may be at least 40% greater than that of an otherwise identical device disposed in a structure without the first dielectric stack. The substrate may have a treated surface such that light that may otherwise be waveguided in the substrate is outcoupled into air, and the average outcoupling efficiency into air of the device over a bandwidth of at least 300 nm may be at least 10% greater than that of an otherwise identical device disposed in a structure without the first dielectric stack. The structure may include an optical cavity defined by a first end layer and a second end layer, where the first end layer further comprising a first dielectric stack having a plurality of layers comprising a first dielectric material, wherein at least two of the layers comprising a first dielectric material have substantially different thicknesses, and a plurality of layers comprising a second dielectric material. An optoelectronic device having a first active layer may be disposed within the optical cavity.

Claims

1. A structure, comprising:

a substrate;

a device disposed over the substrate; and

a first dielectric stack disposed between the substrate and the device, wherein the first dielectric stack further comprises;

a plurality of layers comprising a first dielectric material, wherein at least two of the layers comprising a first dielectric material have substantially different thicknesses;

a plurality of layers comprising a second dielectric material;

wherein the average outcoupling efficiency into air of the device over a bandwidth of at least 300 nm is at least 40% greater than that of an otherwise identical device disposed in a structure without the first dielectric stack.

2. The structure of claim 1, wherein the average outcoupling efficiency into air of the device over a bandwidth of at least 300 nm is at least 50% greater than that of an otherwise identical device disposed in a structure without the first dielectric stack.

3. The structure of claim 1, wherein the average outcoupling efficiency into air of the device over a bandwidth of at least 300 nm is at least 60% greater than that of an otherwise identical device disposed in a structure without the first dielectric stack.

4. The structure of claim 1, wherein the light is within the visible spectrum.

5. The structure of claim 1, wherein the device is a light emitting device.

6. The structure of claim 1, wherein the device is an organic light emitting device.

7. The structure of claim 1, wherein at least two of the layers comprising the second dielectric material have substantially different thicknesses.

8. The structure of claim 1, wherein a second dielectric stack is disposed over the device.

9. The structure of claim 1, wherein the first dielectric stack comprises alternating layers of the first dielectric material and the second dielectric material, and does not include any layers of a third dielectric material.

10. The structure of claim 1, wherein the second dielectric stack further comprises a layer comprising a third dielectric material.

11. A structure, comprising:

a substrate having a treated surface that improves the outcoupling of light from the substrate into air;

a device disposed over the substrate; and

a first dielectric stack disposed between the substrate and the device, wherein the first dielectric stack further comprises;

a plurality of layers comprising a first dielectric material, wherein at least two of the layers comprising a first dielectric material have substantially different thicknesses;

a plurality of layers comprising a second dielectric material

wherein the outcoupling efficiency into air of the device is at least 10% greater than that of an identical device in a structure without a dielectric stack.

12. The structure of claim 11, wherein the outcoupling efficiency into air of the device is at least 14.7% greater than that of an identical device in a structure without a dielectric stack.

13. A structure, comprising:

an optical cavity defined by a first end layer and a second end layer;

the first end layer further comprising a first dielectric stack, wherein the first dielectric stack further comprises;

a plurality of layers comprising a first dielectric material, wherein at least two of the layers comprising a first dielectric material have substantially different thicknesses;

a plurality of layers comprising a second dielectric material, an optoelectronic device having a first active layer disposed within the optical cavity.

14. The structure of claim 13, wherein the second end layer further comprises an at least partially reflective layer.

15. The structure of claim 13, wherein the second end layer further comprises a reflective electrode that is a part of the first optoelectronic device.

16. The structure of claim 13, wherein the second end layer is a dielectric stack.

17. The structure of claim 13, wherein the optoelectronic device is a solar cell, and wherein the short-circuit photocurrent of the solar cell when the structure is exposed to a solar spectra is at least 10% greater than the short-circuit photocurrent of a structure without the first dielectric stack.

18. The structure of claim 17, wherein the optoelectronic device is a solar cell, and wherein the short-circuit photocurrent of the solar cell when the structure is exposed to a solar spectra is at least 13% greater than the photocurrent out of a structure without the first dielectric stack.

19. The structure of claim 18, wherein the optoelectronic device is a solar cell, and wherein the short-circuit photocurrent of the solar cell when the structure is exposed to a solar spectra is at least 16% greater than the photocurrent out of a structure without the first dielectric stack.

20. The structure of claim 13, wherein the structure further comprises a second optoelectronic device having a second active layer disposed within the optical cavity.

21. The structure of claim 13, wherein the first optoelectronic device is an organic solar cell.

22. The structure of claim 13, wherein the first optoelectronic device is a photodetector.

23. The structure of claim 13, wherein the average absorption efficiency of the first active layer is at least 10% greater than that of a first active layer disposed a structure without the first dielectric stack, for wavelengths in the range of 450 nm to 750 nm.

24. The structure of claim 23, wherein the average absorption efficiency of the first active layer is at least 15% greater than that of a first active layer disposed a structure without the first dielectric stack, for wavelengths in the range of 450 nm to 750 nm.

25. The structure of claim 24, wherein the average absorption efficiency of the first active layer is at least 20% greater than that of a first active layer disposed a structure without the first dielectric stack, for wavelengths in the range of 450 nm to 750 nm.