Metallized hyperbranched polydiyne: a photonic material with a large refractive index tunability and a spin-coatable catalyst for facile fabrication of carbon nanotubes

A cobalt-containing hyperbranched polydiyne shows refractive indexes (n) as high as 1.713-1.813 in the long wavelength region, which can be tuned to a large extent (Delta n up to similar to 0.048) by UV irradiation; the polymer can also function as a spin-coatable catalyst for the growth of carbon nanotubes.