Filtered cathodic vacuum arc technique has been used to deposit amorphous carbon (a-C) films of varying thicknesses from 10 nm to 38 nm on catalytic nickel thin film grown on SiO2/Si substrates. Subsequently, a-C films were annealed in vacuum in the temperature range from 650 to 850 °C. Micro-Raman spectroscopic study in combination with optical microscopy and scanning electron microscopy has revealed few layer graphene formations with optical transmittance in the range 85%–88% with a-C films deposited with 10 nm and 18 nm thicknesses. The optimum temperature of annealing was observed to be 750 °C.
Abstract-Filtered cathodic vacuum arc technique has been used to deposit amorphous carbon films of varying thickness on catalytic nickel thin film grown on SiO 2 /Si substrates. Subsequently these a-C films were annealed in vacuum at 650 ºC. Raman spectroscopy together with optical microscopy and scanning electron microscopy has revealed multilayer graphene formation.
This paper reports the direct deposition of multiwalled carbon nanotube (MWCNT)-graphene like hybrid films on nickel substrate using a 2.45 GHz microwave plasma enhanced chemical vapor deposition (MW PECVD) system in the temperature range of 500-700 C at 20 Torr pressure. The films have been characterized by Raman spectra, high resolution transmission electron microscope (HRTEM), scanning electron microscope, high resolution X-ray diffraction and contact angle measurement. Raman spectroscopy and HRTEM reveal the formation of MWCNT and graphene like hybrid carbon sheet structures. The effect of processing temperature on the field emission properties of MWCNT-graphene like hybrid films has been investigated. Field emission measurement reveals that the turn-on field decrease and the emission current density increase with the increase of deposition temperature. The rambutan structure of MWCNT formed at 700 C is responsible for the improvement in the field emission properties. The film deposited at 700 C shows fast response and recovery time of 40 and 96 s, respectively, for ammonia gas sensing due to the high surface area of the film. It has also been found that the hydrophobic surface of the film helps to perform the gas sensing in the humid environment.
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