Dataset on large area nano-crystalline graphite film (NCG) grown on SiO2 using plasma-enhanced chemical vapour deposition

Abstract

A Si wafer coated with a low temperature oxide (LTO) was used as substrate (Si/SiO 2 ) during the deposition of a thick nano-crystalline graphite (NCG) film by means of plasma-enhanced chemical vapour deposition (PECVD) procedure. The process parameters, the atomic force (AFM) and scanning electron (SEM) micrographs, Raman spectrum and X-ray diffraction (XRD) pattern are herein illustrated. The as deposited NCG film was electrochemically pretreated (3 mA applied current, during 240 s, in 10 mM phosphate buffer saline (PBS) solution containing 0.1 M KCl, pH 7) and thereafter used as electrode for sensing the caffeic acid content in lyophilised berries and dried chokeberries in “Nano-crystalline graphite film on SiO 2 : Electrochemistry and electro-analytical application” [1].

Nanocrystalline graphite thin layers for low-strain, high-sensitivity piezoresistive sensing

“…The sp 2 discontinuities and disorder, as well as the turbostratic stacking, are reflected by the blue shift of the G peak from its ideally graphitic value of 1580 cm −1 , by the full width at half maximum (FWHM) values of the main peaks (~67.23 cm −1 and 71.91 cm −1 , for D and G, respectively) and by the presence of the defect related D+D' peak, while the position and configuration of the 2D peak additionally confirm the turbostratic nature of the material [39,40]. The dominant interlayer spacing derived from these drifted quantities results of d 002~3 .5 Å [39], that is identical with the X-ray diffraction derived value [24,25]. A rough approximation of an equivalent lateral size of the average crystallite (La) in the material can be calculated based on the I D /I G intensity ratio of the main peaks.…”

“…A proposed nomenclature for the diversified carbonic structures can be consulted in [23]. While respecting the aforementioned nomenclature as much as possible and considering its various characterizations [24][25][26], we define the material used in this work as bulk-NCG: a thick and hard carbonic film consisting of 3D randomly orientated, graphite nanocrystals with a dominant turbostratic packing [27] Thin films belonging to the broad class of NCG [27] have shown promise in applications such as: field emis-sion [28], electrochemical sensing [25,29,30], photodetection [31,32], nanoelectromechanical (NEM) switching [19], fabrication of microelectromechanical (MEM) resonators [20], protective coating [33] or gas separation [34]. The inhomogeneous conductive pathways formed by the sp 2 domains provide the material with a special functionality and a high conductivity response to small strains [10,18,35].…”

Properties of Nitrogen-Doped Nano-Crystalline Graphite Thin Films and Their Application as Electrochemical Sensors

“…Well-defined reversible redox peaks were observed for the tested electrodes with peak separations (ΔE) of 85 mV (GC), 76 mV (N-NCG 3), 83 mV (N-NCG 5), and 91 mV (N-NCG 7), confirming a reversible redox mechanism as expected for K 3 [Fe(CN) 6 ]. As illustrated in our previous studies, 9,18 the undoped NCG electrode required electrochemical activation treatment. However, for the N-NCG electrodes, this preactivation step was not necessary, and we speculated that nitrogen doping induced defects on the carbon structure via increased edge plain exposure.…”

“…36 Electrochemical behavior of the N-NCG 3, N-NCG 5, and N-NCG 7 films.-An edge plane is considerably more active than a basal plane, and film deposition techniques are the most advantageous method to modify carbon materials 14 to generate numerous surface edge planes. In our previous studies, 9,18 we investigated undoped NCG and electrochemically preactivated the NCG electrode to promote enhanced electrochemical reversibility by increasing the availability of edges because the electrochemical activity of carbon electrodes depends on their structure. 1,10 Heteroatom-doped carbons, mainly nitrogen-doped carbons, exhibited multifunctional catalytic activity.…”

“…Nitrogen-doped nano-crystalline graphite film growth.-The PECVD growth process (Table I) was inspired from our previous work. 9,18 The PECVD growth of the NCG films depends on the dissociation of hydrocarbon precursors (CH 4 in this particular case) in the plasma phase and the subsequent adsorption of the carbon radicals onto the substrate surface, where they nucleate and form two-dimensional (2D) rings of sp 2 -hybridized carbon owing to the high surface energy and ion bombardment from the plasma. This process is followed by edge growth of the initially formed nuclei with lateral expansion until full surface coverage is achieved.…”