Laser Ablated Carbon Thin Film from Carbon Nanotubes and Their Property Studies

A carbon nanotube (CNT) of diameter ~20 nm has been synthesized by spray pyrolysis of turpentine oil using Ni/Fe catalyst. Pellet of CNTs has been used as a target to produce semiconducting carbon thin film of band gap 1.4 eV. Presence of oxygen pressure in the pulse laser deposition (PLD) chamber helped to control the $sp^3/sp^2$ ratio to achieve the desired band gap. Results are discussed with the help of Raman spectra, SEM TEM micrographs and optical measurements suggest that semiconducting carbon thin film deposited by PLD technique has retained its nanotubes structure except that its diameter has increased from 20 nm to 150 nm.