Properties of iodine doping in amorphous carbon thin films grown by chemical vapor deposition (CVD) method / Norshamimi Ahmad

The amorphous carbon (a-C) thin film was deposited by thermal chemical vapor deposition (CVD) technique as the most economical method that using argon (Ar) as carrier gas. The influence of iodine doping on the properties of electrical, optical, and structural for amorphous carbon (a-C) thin films that deposited on glass and quartz substrate at deposition temperature ranging from 500 °C to 700 °C were reported. In this work, the iodine doping process is introduced for alteration of undoped a-C thin film as it has shortage in properties. The films were characterized by Perkin Elmer (LAMBDA 750) UV/VIS/NIR spectrophotometer for optical properties, BUKOH KEIKI (CEP200) Solar Simulator for electrical properties, while Raman spectroscope HORIBA Jobin Yvon (HR800) and Atomic force microscopy (AFM) were used for structural properties. From the characterization of electrical properties, the I-V measurement revealed that I-doping increased the conductivity as the temperature increased. The optical band gap decreased from 0.60 eV to 0.15 eV for iodine doped of the thin films. The Raman spectral result shows that graphitization of the films intensified after iodine doping introduced. The surface morphology of the thin films indicates the roughness of the thin films decreased as the deposition temperature increased.