System and process for producing nanowire composites and electronic substrates therefrom
The present invention relates to a system and process for producing a nanowire-material composite. A substrate having nanowires attached to a portion of at least one surface is provided. A material is deposited over the portion to form the nanowire-material composite. The process further optionally includes separating the nanowire-material composite from the substrate to form a freestanding nanowire-material composite. The freestanding nanowire material composite is optionally further processed into a electronic substrate. A variety of electronic substrates can be produced using the methods described herein. For example, a multi-color light-emitting diode can be produced from multiple, stacked layers of nanowire-material composites, each composite layer emitting light at a different wavelength.
1. A process for depositing oriented nanowires comprising:
(a) providing a first substrate having nanowires attached to a portion of at least one surface, wherein each nanowire has a first end attached to said portion; and
(b) depositing a material over said portion to form a nanowire-material composite;
(c) patterning said nanowire-material composite to form a patterned composite;
(d) separating said patterned composite from said first substrate; and
(e) applying said patterned composite to a second substrate such that said nanowires are aligned substantially parallel to said second substrate.
2. The process for depositing oriented nanowires according to claim 1 , further comprising before (a):
growing said nanowires on said first substrate such that a portion of each nanowire at said end is doped.
3. The process for depositing oriented nanowires according to claim 1 , wherein (a) comprises:
providing a parting layer on said first substrate, wherein said nanowires are attached to a portion of said parting layer.
4. The process for depositing oriented nanowires according to claim 3 , wherein (d) comprises:
separating said parting layer from said first substrate and said nanowire-material composite.
5. The process for depositing oriented nanowires according to claim 1 , wherein said nanowires have lengths between about 10 to about 20 microns long.
6. The process for depositing oriented nanowires according to claim 1 , wherein (a) comprises:
providing said first substrate having said nanowires attached substantially perpendicular to a portion of at least one surface.
7. The process for depositing oriented nanowires according to claim 1 , wherein (b) comprises:
depositing said material such that said material covers said nanowires.
8. The process for depositing oriented nanowires according to claim 1 , wherein said material is a polymer, prepolymer, ceramic, glass, metal or composite thereof.
9. The process for depositing oriented nanowires according to claim 1 , wherein said material is an elastomer, thermoplastic or thermosetting resin.
10. The process for depositing oriented nanowires according to claim 1 , wherein said material comprises a mixture of at least two or more epoxy prepolymers.
11. The process for depositing oriented nanowires according to claim 1 , wherein said material comprises a mixture of a monomer and an initiator.
12. The process for depositing oriented nanowires according to claim 11 , further comprising after (b):
photopolymerizing said monomer to form a hardened nanowire-material composite.
13. The process for depositing oriented nanowires according to claim 1 , further comprising after (b):
doping said nanowire-material composite.
14. The process for depositing oriented nanowires according to claim 13 , wherein said doping comprises:
doping a second end of said nanowires.
15. The process for depositing oriented nanowires according to claim 1 , wherein (c) comprises:
patterning said nanowire-material composite using an ion etching fluid selected from the group consisting of ions of SF 6 , CF 4 , CHF 3 , CCl 4 , CCl 2 F 2 , Cl 2 , O 2 , H 2 and Ar.
16. The process for depositing oriented nanowires according to claim 1 , wherein (c) comprises:
(l) patterning said nanowire-material composite into a plurality of nanowire-material blocks.
17. The process for depositing oriented nanowires according to claim 7 , wherein (l) further comprises:
patterning said nanowire-material composite into a plurality of nanowire-material blocks, wherein said blocks have a height of less than about 10 microns.
18. The process for depositing oriented nanowires according to claim 16 , wherein (e) comprises:
(l) applying said plurality of nanowire-material blocks to a portion of said second substrate.
19. The process for depositing oriented nanowires according to claim 18 , wherein (e)(l) comprises:
applying said plurality of nanowire-material blocks to a portion of said second substrate in a predetermined pattern.
20. The process for depositing oriented nanowires according to claim 18 , further comprising after (e):
(f) planarizing a portion of said nanowire-material blocks.
21. The process for depositing oriented nanowires according to claim 20 , wherein (f) comprises:
planarizing said nanowire-material blocks using an oxygen plasma to expose a surface of said nanowires.
22. The process for depositing oriented nanowires according to claim 1 , further comprising after (e):
(f) removing said material from said nanowire-material composite to form on said second substrate a thin film of nanowires aligned substantially parallel to said second substrate and having a sufficient density to achieve an operational current level;
(g) defining a plurality of semiconductor device regions in said thin film of nanowires; and
(h) forming contacts at the semiconductor device regions to thereby provide electrical connectivity to the plurality of semiconductor devices.
23. The process for depositing oriented nanowires according to claim 1 , wherein said second substrate is a liquid crystal display backplate.