Nanosubstrate with conductive zone and method for its selective preparation

Abstract

The present invention provides novel nanostructure composed of at least one elongated structure element, an elongated structure element of said nanostructure bearing an electrically conductive zone selectively grown onto the elongated structure element. The present invention further provides a selective method for forming in a liquid medium, such nanostructures.

1 . Nanostructure composed of at least one elongated structure element and comprising a first material, an elongated structure element of said nanostructure bearing an electrically conductive zone made of a second material.  
     
     
         2 . The nanostructure of  claim 1 , wherein said first material is selected from semiconductor material, insulating material, metallic material and mixtures thereof.  
     
     
         3 . The nanostructure of  claim 2  wherein said first material is a semiconductor material.  
     
     
         4 . The nanostructure of  claim 3  wherein said semiconductor material is selected from Group II-VI semiconductors, Group III-V semiconductors, Group IV-VI semiconductors, Group IV semiconductors, alloys made of these semiconductors, combinations of the semiconductors in composite structures and core/shell structures of the above semiconductors.  
     
     
         5 . The nanostructure of  claim 4  wherein said nanostructures are made from Group II-VI semiconductors, alloys made from Group II-VI semiconductors and core/shell structures made from Group II-VI semiconductors.  
     
     
         6 . The nanostructure of  claim 1  wherein said second material is selected from metal and metal alloy.  
     
     
         7 . The nanostructure of  claim 6  wherein said metal is a transition metal.  
     
     
         8 . The nanostructure of  claim 7  wherein said transition metal is selected from Cu, Ag, Au, Pt, Co, Pd, Ni, Ru, Rh, Mn, Cr, Fe and Ti.  
     
     
         9 . The nanostructure of  claim 1  having an elongated shape selected from rod, bipod, tripod and tetrapod.  
     
     
         10 . A method for forming in a liquid medium, an electrically conductive zone on a nanostructure having at least one elongated structure element, the method comprising: contacting a solution comprising nanostructures with a solution comprising a metal or metal alloy source, to obtain upon isolation nanostructures bearing at least one electrically conductive zone on said at least one elongated structure thereof.  
     
     
         11 . The method according to  claim 10  wherein said nanostructure is made of a material comprising semiconductor material, insulating material, metallic materialor mixtures thereof.  
     
     
         12 . The method according to  claim 10  wherein said nanostructure is made of semiconductor material.  
     
     
         13 . The method according to  claim 10  wherein said nanostructure has an elongated shape.  
     
     
         14 . The method according to  claim 13  wherein said elongated shape comprises a branched shape.  
     
     
         15 . The method according to  claim 14  wherein said branched shape comprises rod, bipod, tripod and tetrapod.  
     
     
         16 . The method according to  claim 12  wherein said nanostructure is made of a semiconductor material selected from Group II-VI semiconductors, Group III-V semiconductors, Group IV-VI semiconductors, Group IV semiconductors, alloys made of these semiconductors, combinations of the semiconductors in composite structures and core/shell structures of the above semiconductors.  
     
     
         17 . The method according to  claim 16 , wherein said nanostructures are made from Group II-VI semiconductors, alloys made from Group II-VI semiconductors and core/shell structures made from Group II-VI semiconductors.  
     
     
         18 . The method according to  claim 11  wherein said nanostructure is made of an insulating material selected from oxides and organic polymers.  
     
     
         19 . The method according to  claim 10  wherein the metal or metal alloy source solution further comprises a surfactant and/or a stabilizer.  
     
     
         20 . The method according to  claim 19  wherein said surfactant is a cationic surfactant.  
     
     
         21 . The method according to  claim 19  wherein said stabilizer prevents aggregation of nanoparticles during the formation of an electrically conductive zone on a nanostructure.  
     
     
         22 . The method according to  claim 20  wherein said stabilizer is selected from ammonium salts, alkyl pyridinium alts and quaternary ammonium salts.  
     
     
         23 . The method according to  claim 10  wherein said metal or metal alloy source comprises a transition metal element.  
     
     
         24 . The method according to  claim 23  wherein said metal or metal alloy source is a salt of a transition metal or transition metal alloy.  
     
     
         25 . The method according to  claim 24  wherein said transition metal is selected from Cu, Ag, Au, Pt, Co, Pd, Ni, Ru, Rh, Mn, Cr, Fe and Ti.  
     
     
         26 . The method according to  claim 24  wherein said metal or metal alloy salt is first dissolved in an organic solvent comprising a surfactant and/or a stabilizer to give a mixture which is subsequently added in a controllable manner to the nanostructures solution.  
     
     
         27 . The method according to  claim 10  wherein said electron donor is an organic compound.  
     
     
         28 . The method according to  claim 27  wherein said electron donor is selected from aliphatic amine, hydride and ascorbic acid.  
     
     
         29 . A method for forming in solution medium an electrically conductive zone on a nanostructure having at least one elongated structure element, the method comprising: contacting, an organic solution comprising semiconductor nanostructures with an organic solution comprising a metal or metal alloy source, a stabilizer and/or surfactant and/or electron donor to obtain upon precipitation semiconductor nanostructures bearing at least one electrically conductive zone on said at least one elongated structure thereof.  
     
     
         30 . The method according to  claim 29  wherein said nanostructures are in the form of nanorods, bipods, tripods or tetrapods.  
     
     
         31 . The method according to  claim 29  wherein said semiconductor nanostructures are made of a material comprising elements of Group II-VI, alloys of such elements or core-shall layered structures thereof.  
     
     
         32 . The method according to  claim 31  wherein said semiconductor nanoparticles are made of a material comprising CdSe, CdS, CdTe, alloys thereof, combinations thereof or core/shell layered-structures thereof.  
     
     
         33 . The method according to  claim 29  wherein said electrically conductive zone comprises a metal selected from Au, Ag, Cu, Pt, Co, Pd, Ni, Ru, Rh, Mn, Cr, Fe, Ti or mixtures of such metals.  
     
     
         34 . Article of manufacture comprising the nanostructure of  claim 1 .  
     
     
         35 . An electronic device comprising the nanostructure of  claim 1 , or into which the nanostructure of  claim 1  is integrated.  
     
     
         36 . An electrode comprising the nanostructure of  claim 1 .  
     
     
         37 . An optical device comprising the nanostructure of  claim 1 , or into which the nanostructure of  claim 1  is integrated.  
     
     
         38 . Self assembled construct comprising a plurality of nanostructures according to  claim 1 , wherein each nanostructure is linked to another nanostructure in the construct through its conductive zone.