US Patent 8197789 - Selective elimination of metallic carbon nanotubes

http://www.freepatentsonline.com/8197789.html

The fabrication of single walled carbon nanotubes usually results in a mixture of nanotubes with metallic and semiconducting properties. This patent from Samsung teaches using xenon or infrared lamps to remove the metallic nanotubes. Claim 1 reads:

1. A method for selectively eliminating metallic carbon nanotubes, the method comprising:

irradiating carbon nanotubes with light having a continuous spectrum of wavelengths of about 180 nm to about 11 μm and an intensity of about 30 mW/cm² to about 300 mW/cm² to selectively eliminate metallic carbon nanotubes.