Crystals comprising single-walled carbon nanotubes

Abstract

The invention is directed to a method of manufacturing single-walled carbon nanotubes comprising the steps of providing on a substrate at least one pillar comprising alternate layers of a first precursor material comprising fullerene molecules and a second precursor material comprising a catalyst, and heating the at least one pillar. It further is directed to a precursor arrangement for manufacturing single-walled carbon nanotubes comprising on a substrate at least one pillar comprising alternate layers of a first precursor material comprising fullerene molecules and a second precursor material comprising a catalyst. A third aspect is a nanotube arrangement comprising a substrate and thereupon at least one crystal comprising a bundle of single-walled carbon nanotubes with essentially identical orientation and structure.

1 . Method of manufacturing single-walled carbon nanotubes ( 19 ) comprising the steps of 
 a) providing on a substrate ( 4 ) a plurality of pillars ( 8 ) comprising alternate layers of a first precursor material ( 15 ) comprising fullerene molecules and a second precursor material ( 16 ) comprising a catalyst,    b) heating the plurality of pillars ( 8 ).    
     
     
         2 . Method according  claim 1  whereby the substrate ( 4 ) is selected to offer at least one crystallisation site for growing the single-walled carbon nanotubes ( 19 ).  
     
     
         3 . Method according to one of claims  1  or  2  whereby the substrate ( 4 ) is selected to comprise thermally oxidized silicon or molybdenum in the form of a grid or as a solid film provided on a silicon wafer.  
     
     
         4 . Method according to one of  claims 1  to  3  whereby for providing the the plurality of pillars ( 8 ) between 5 and 10 layers of the precursor materials ( 15 ,  16 ) are deposited upon each other, each layer having a thickness between 5 and 30 nm.  
     
     
         5 . Method according to one of  claims 1  to  4  whereby the precursor materials ( 15 ,  16 ) are deposited through a shadow mask ( 7 ) comprising one or more apertures ( 14 ).  
     
     
         6 . Method according to one of  claims 1  to  5  whereby the precursor materials ( 15 ,  16 ) are provided by thermal evaporation.  
     
     
         7 . Method according to  claim 6  whereby the evaporation of the precursor materials ( 15 ,  16 ) is performed at a pressure of around 10 −9  Torr, and whereby the substrate ( 4 ) is kept at room temperature.  
     
     
         8 . Method according to  claim 6  or  7  whereby the evaporation of the precursor materials ( 15 ,  16 ) is controlled by using a shuttering mechanism ( 18 ) and an in situ balance for monitoring the deposition rate for the precursor materials ( 15 ,  16 ).  
     
     
         9 . Method according to one of  claims 6  to  8  whereby the evaporation is controlled such that the thickness of the layers decreases with their distance from the substrate ( 4 ).  
     
     
         10 . Method according to one of  claims 1  to  9  whereby the heating is performed up to a temperature of essentially 950° C. in a vacuum of essentially 10 −6  Torr or in an essentially inert gas atmosphere, for a time between 3 minutes and an hour.  
     
     
         11 . Precursor arrangement for manufacturing single-walled carbon nanotubes ( 19 ) comprising on a substrate ( 4 ) a plurality of pillars ( 8 ) comprising alternate layers of a first precursor material ( 15 ) comprising fullerene molecules and a second precursor material ( 16 ) comprising a catalyst.  
     
     
         12 . Precursor arrangement according to  claim 11 , wherein the layers have a thickness that decreases with their distance from the substrate ( 4 ).  
     
     
         13 . Precursor arrangement according to  claim 11  or  12 , wherein the substrate ( 4 ) has at least one crystallisation site for growing the single-walled carbon nanotubes ( 19 ), said substrate ( 4 ) preferably comprising thermally oxidized silicon or molybdenum in the form of a grid or as a solid film provided on a silicon wafer.  
     
     
         14 . Precursor arrangement according to one of  claims 11  to  13 , wherein the second precursor material ( 16 ) comprises a magnetic material, preferably a metal being selected from the group Ni, Co, Fe, Mo.  
     
     
         15 . Nanotube arrangement comprising a substrate ( 4 ) and thereupon at least one crystal ( 20 ) comprising a bundle of single-willed carbon nanotubes ( 19 ) with essentially identical orientation and structure.  
     
     
         16 . Nanotube arrangement according to  claim 15  wherein the substrate ( 4 ) has a surface with crystallisation sites wherefrom the single-walled carbon nanotubes ( 19 ) have grown, preferably comprising thermally oxidized silicon or molybdenum in the form of a grid or as a solid film provided on a silicon wafer.  
     
     
         17 . Nanotube arrangement according to  claim 15  or  16  wherein in the case of several crystals ( 20 ), said crystals ( 20 ) are essentially parallel to each other.  
     
     
         18 . Nanotube arrangement according to one of  claims 15  to  17  wherein the single-walled carbon nanotubes ( 19 ) are essentially straight along their length.  
     
     
         19 . Nanotube crystal comprising a bundle of straight single-walled carbon nanotubes ( 19 ) with essentially identical orientation and structure.  
     
     
         20 . Display, electrical circuit, switching element or sensor element comprising at least one nanotube arrangement according to one of  claims 15  to  18  or at least one nanotube crystal ( 20 ) according to  claim 19.