Nanowire structures and devices for use in large-area electronics and methods of making the same

1 . A nanowire structure, comprising:

a nanowire defining an axis, wherein the nanowire comprises a first end and a second end, and wherein the first end is axially spaced from the second end; and

magnetic segments coupled to the first and second ends of the nanowire.

2 . The nanowire structure of claim 1 , wherein the nanowire comprises a semiconductor.

3 . The nanowire structure of claim 1 , further comprising a shell that is coupled to the nanowire and spaced radially from the axis of the nanowire.

4 . The nanowire structure of claim 3 , wherein the shell comprises an oxide of a material of the nanowire.

5 . The nanowire structure of claim 4 , wherein the nanowire comprises silicon, and wherein the shell comprises silicon oxide.

6 . The nanowire structure of claim 1 , further comprising a dielectric layer coupled to the nanowire or the shell and spaced radially from the axis of the nanowire.

7 . The nanowire structure of claim 1 , wherein at least a portion of the nanowire is doped.

8 . The nanowire structure of claim 7 , wherein the nanowire includes a first doped region and a second doped region, and wherein the first and second doped regions are similarly doped.

9 . The nanowire structure of claim 8 , further comprising a third region, wherein the third region is disposed between the first and second regions, and wherein the third region is intrinsic or lowly doped.

10 . The nanowire structure of claim 7 , wherein the nanowire includes a first doped region and a second doped region, and wherein the first and second doped regions are oppositely doped.

11 . The nanowire structure of claim 10 , further comprising a third region disposed between the first and second regions, and wherein the third region is intrinsic or lowly doped.

12 . The nanowire structure of claim 1 , wherein a diameter of the nanowire is in a range from about 5 nanometers to about 1000 nanometers.

13 . The nanowire structure of claim 1 , wherein the magnetic segments comprise a metal, a conductive polymer, a ceramic, or combinations thereof.

14 . The nanowire structure of claim 13 , wherein the metal comprises nickel, cobalt, iron, or combinations thereof.

15 . The nanowire structure of claim 1 , wherein the magnetic segments form Ohmic contacts with the nanowire.

16 . The nanowire structure of claim 1 , further comprising a capping layer disposed radially around the magnetic segments.

17 . A device, comprising:

a substrate;

a nanowire structure disposed on the substrate and comprising:

a nanowire defining an axis and comprising a semiconductor material, wherein the nanowire comprises a first end and a second end, wherein the first end is axially spaced from the second end;

magnetic segments coupled to the first and second ends of the nanowire; and

a first magnetic microelectrode and a second magnetic microelectrode coupled to the magnetic segments of the nanowire structure,

wherein the nanowire structure is configured to electrically couple the first and second magnetic microelectrodes, and wherein the nanowire structure is configured to be aligned in a predetermined direction under the influence of a magnetic filed.

18 . The device of claim 17 , further comprising a shell coupled to the nanowire and spaced radially from the axis of the nanowire, and wherein the shell comprises an oxide.

19 . The device of claim 17 , further comprising a first capping pad for the first magnetic microelectrode and a second capping pad for the second magnetic microelectrode disposed on the substrate such that the first and second capping pads each are coupled to the magnetic segments.

20 . The device of claim 17 , further comprising a third electrode disposed on the substrate and electrically insulated from the first and second magnetic microelectrodes.

21 . The device of claim 20 , wherein the third electrode is disposed on an undoped portion of the nanowire, and wherein the undoped portion is disposed between two doped portions of the nanowire.

22 . The device of claim 17 , wherein the first and second magnetic microelectrodes are disposed on the substrate, and wherein a third electrode is coupled to the nanowire structure.

23 . The device of claim 17 , wherein the device comprises a transistor such that the first magnetic microelectrode is a drain electrode and the second magnetic microelectrode is a source electrode.

24 . The device of claim 17 , wherein the magnetic field is a local magnetic filed generated between the first and second contact pads, or an external magnetic field, or both.

25 . The device of claim 17 , comprising a photodetector, a light emitting diode, a transistor, or combinations thereof.

26 . The device of claim 17 , wherein the device is employed in a radio frequency identification tag, an X-ray imager, a display device, or combinations thereof.

27 . An article, comprising:

a nanoscale semiconducting pathway having a first end and a second end; and

magnetically responsive portions coupled to the first and second ends of the pathway, wherein the magnetically responsive portions are configured to align the article in response to a magnetic field.

28 . A method of making a nanowire structure, comprising:

providing a substrate;

forming a porous layer on the substrate;

depositing a magnetic material layer in the pores to form first magnetic segments; and

depositing a nanowire material on the magnetic material layer to form nanowires on each of the first magnetic segments.

29 . The method of claim 28 , wherein the substrate comprises a semiconductor, a plastic, a flexible material, or combinations thereof.

30 . The method of claim 28 , wherein the step of disposing the porous layer comprises:

depositing a metal film on the substrate; and

anodizing the metal film to convert the metal film into a porous anodized metal oxide layer.

31 . The method of claim 28 , wherein the metal film comprises aluminum.

32 . The method of claim 28 , wherein the step of depositing the nanowire material comprises chemical vapor deposition.

33 . The method of claim 28 , further comprising depositing a dissolvable metal layer between the substrate and the metal film.

34 . The method of claim 28 , further comprising depositing a catalyst on the magnetic metal prior to depositing the semiconductor material on the magnetic metal to form the nanowires.

35 . The method of claim 28 , further comprising slicing a portion of at least one nanowire to form a nanowire having a predetermined length, wherein the slicing comprises:

depositing a photo-resist film on the nanowires; and

etching a portion of the at least one nanowire.

36 . The method of claim 28 , further comprising depositing second magnetic segments on each of the nanowires.

37 . The method of claim 28 , further comprising oxidizing the nanowires to form oxide layers on each of the nanowires to form the nanowire structures.

38 . A method of making a device, comprising:

providing a substrate;

disposing a first magnetic microelectrode and a second magnetic microelectrode on the substrate;

disposing a plurality of nanowire structures between the first and second magnetic microelectrodes; and

aligning the plurality of nanowire structures, such that a majority of the nanowire structures are parallel to each other and are in operative association with the first and second magnetic microelectrodes to electrically couple the first and second magnetic microelectrodes.

39 . The method of claim 38 , wherein the substrate is a flexible substrate.

40 . The method of claim 38 , wherein the step of aligning the plurality of nanowires comprises aligning the plurality of nanowires under the influence of a magnetic field.

41 . The method of claim 40 , where the magnetic field is a local magnetic field between the first and second magnetic microelectrode, or external magnetic field, or both.