Preparation and characterization of boron-incorporated amorphous carbon films from a natural source of camphoric carbon as a precursor material

The boron-incorporated amorphous carbon (a-C:B) film has been prepared by pulsed laser deposition (PLD) in high vacuum at room temperature using natural source of camphoric carbon (CC) as a precursor material. The effects of various B weight percentages in the target (Bwt.%) on the properties of a-C:B films have been investigated using standard measurement techniques and discussed. The optical band gap (Eg) is almost unchanged up to 10 Bwt.%, decreased a little, and with decrease of electrical resistivity (ρ) with higher Bwt.%, we considered that the variation of Eg and electrical properties can be related to interstitial doping of B in carbon films through modifications of C-B bonding configurations by rearranging B atoms and the B incorporation induced by doping, which are responsible for the decrease in ρ. The decrease of ρ is considered not due to the graphitization caused by the increase of sp2-bonded carbon. This is further confirmed by the variation of surface morphology (AFM), Raman and FT-IR as the structural and bonding properties of these films was unchanged with B incorporation up to 16 Bwt.%.