Electrical and optical properties of iodine doped amorphous carbon thin film by Thermal CVD

In this paper, iodine doped amorphous carbon thin films with varying the doping time were prepared onto glass and n-type silicon substrates by Thermal CVD technique. The optical and electrical properties of iodine doped amorphous carbon thin films were characterized by using UV-VIS-NIR spectroscopy and current-voltage (I-V) measurement respectively. The optical band gap of a-C thin films shows a reduction of the optical band gap upon iodine doping. The higher electrical conductivity was found to be at 10 min iodine doping. The structural properties of the films were studied by FESEM and FTIR. FESEM studies shows a uniform distribution of fine small particles on the iodine doped a-C thin films indicating deposition of iodine atoms on the substrates. FTIR measurement shows the effect of iodine on reduction on sp³ bonded carbon in a-C thin film.