Patent ID: 8821975

Claim:
A method for making a branched carbon nanotube structure, the method comprising steps, as follows: providing a substrate and forming a buffer layer on a surface of the substrate, wherein the buffer layer is made of at least one material selected from the group consisting of alumina and silicon dioxide; depositing a catalyst layer on a surface of the buffer layer, material of the catalyst layer being non-wetting with material of the buffer layer at a temperature that the branched carbon nanotube structure is formed, wherein the catalyst layer is made of a noble metal; putting the substrate with the buffer layer and the catalyst layer formed thereon into a reactive device; and forming the branched carbon nanotubes on the surface of the buffer layer and along the surface of the buffer layer by a chemical vapor deposition method; wherein the chemical vapor deposition method comprises steps as follows: heating the substrate up to a predetermined temperature; introducing a protective gas for a first predetermined time until the catalyst layer is melted and forms into a plurality of catalyst balls; introducing a carbon-containing gas for a second predetermined time; and forming the branched carbon nanotube structure on the surface of the buffer layer and along the surface of the buffer layer, wherein the catalyst balls are movable on and along the surface of the buffer layer and encounter and incorporate with adjacent catalyst balls to form a plurality of new catalyst balls.