Light emitting nanowire device

• US 7,906,354 B1
• Filed: 03/30/2010
• Issued: 03/15/2011
• Est. Priority Date: 03/30/2010
• Status: Active Grant

• Current Assignee: Nanoco Technologies Limited (Nanoco Group Plc)
• Original Assignee: Eastman Kodak Company
• Inventors: Ellinger, Carolyn R., Kahen, Keith B.
• Primary Examiner(s): Geyer; Scott B
• Application Number:
  US12/749,929
• Time in Patent Office: 350 Days
• Field of Search: None
• US Class Current: 438/26
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: H01L 29/0676 oriented perpendicular or at an angle to a substrate
• CPC Class Codes: H01L 29/068 comprising a junction
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/18 within the light emitting region
• CPC Class Codes: Y10S 977/762 Nanowire or quantum wire, i.e. axially elongated structure having two dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/832 having specified property, e.g. lattice-constant, thermal expansion coefficient
• CPC Class Codes: Y10S 977/882 Assembling of separate components, e.g. by attaching

Abstract

Method of making a light emitting semiconductor nanowire device includes providing a plurality of spaced light emitting semiconductor nanowires on a growth substrate; applying a dielectric material disposed between the semiconductor nanowires producing a layer of embedded semiconductor nanowires having a top surface opposed to a bottom surface, wherein the bottom surface is defined by the interface with the growth substrate; depositing a first electrode over the top surface in electrical contact with the nanowires; joining the first electrode to a device substrate; removing the growth substrate and exposing the bottom surface of the layer of embedded nanowires; depositing a second electrode on the bottom surface of the nanowires so that it is in electrical contact with the nanowires; and wherein either the first or second electrode is transparent to permit light to be transmitted from the light emitting semiconductor nanowires through the transparent electrode.

Claims

1. A method of making a light emitting semiconductor nanowire device comprising:

(a) providing a plurality of spaced light emitting semiconductor nanowires on a growth substrate;

(b) applying a dielectric material so that it is disposed between the semiconductor nanowires producing a layer of embedded semiconductor nanowires having a top surface opposed to a bottom surface, wherein the bottom surface is defined by the interface with the growth substrate;

(c) depositing a first electrode over the top surface of the layer of embedded semiconductor nanowires so that it is in electrical contact with the semiconductor nanowires;

(d) joining the first electrode to a device substrate;

(e) removing the growth substrate and exposing the bottom surface of the layer of embedded semiconductor nanowires;

(f) depositing a second electrode on the bottom surface of the layer of embedded semiconductor nanowires so that it is in electrical contact with the semiconductor nanowires; and

(g) wherein either the first or second electrode is transparent to permit light to be transmitted from the light emitting semiconductor nanowires through the transparent electrode.

2. The method of claim 1 wherein the light emitting nanowires include type II-VI, III-V, IV-VI or IV semiconductor materials.

3. The method of claim 2 wherein the light emitting nanowires include core/shell nanowires.

4. The method of claim 3 wherein the core/shell nanowires have cores having discrete internal heterostructure units.

5. The method of claim 1 wherein the dielectric material is a polymer.

6. The method of claim 1 wherein the light emitting nanowires are axial or radial pin diodes.

7. The method of claim 1 wherein step (d) includes using a conductive connection material to form an electrical connection between the first electrode and the device substrate.

8. The method of claim 7 wherein the conductive connection material is a metal and step (d) is provided by:

(i) depositing the metallic conductive connection material on the device substrate;

(ii) melting the metallic conductive connection material; and

(iii) placing the first electrode in contact with the metallic conductive connection material to join the first electrode to the device substrate.

9. The method of claim 1 wherein the device substrate is flexible.

10. The method of claim 1 wherein the device substrate is conductive.

11. The method of claim 1 wherein the second electrode of step (f) is deposited in a pattern.

12. The method of claim 1 wherein step (e) includes using mechanical force to peel the device substrate.

13. The method of claim 1 wherein step (e) includes providing energy to weaken the bond between the semiconductor nanowires and the growth substrate to facilitate the removal of the semiconductor nanowires.

14. An integrated light emitting nanowire device comprising:

(a) a plurality of spaced light emitting semiconductor nanowires each having top and bottom surfaces;

(b) dielectric material disposed between the spaced light emitting semiconductor nanowires;

(c) a first electrode in direct contact with the top surface of the nanowires;

(d) a conductive connection layer in contact with the first electrode;

(e) a second electrode in direct contact with the bottom surface of the nanowires;

(f) a device substrate in contact with the conductive connection layer; and

(g) either the first or second electrode is transparent to permit light to be transmitted through the transparent electrode.

15. The light emitting nanowire device of claim 14 wherein the light emitting semiconductor nanowires include type II-VI, III-V, IV-VI or IV semiconductor materials.

16. The light emitting nanowire device of claim 14 where each light emitting nanowire is a semiconductor pin diode.

17. The light emitting nanowire device of claim 16 where the semiconductor pin diodes are axial or radial pin diodes.

18. The integrated light emitting nanowire device of claim 14 where the conductive connection layer is a metal.