Highly conductive nanoclustered carbon:nickel films grown by pulsed laser deposition

The X-ray detection performance of polycrystalline CVD diamond with pulsed laser deposited carbon electrodes

“…The amorphous carbon upon annealing is highly conductive. Again proof of this has been given in [12] Where excellent electrical properties were achieved in both pure carbon and Ni doped films through annealing at lower temperatures than the ones used for this work. The SNR of Poly-C/Ni and Poly-Pt is higher than 1000, satisfying the recommendations of the IAEA for medical dosimetry devices [14].…”

“…By ablating an sp 2 rich target with short laser pulses a plasma plume with energetic species (ions, small carbon clusters) are formed. Due to the lack of a background gas, the carbon deposited on the substrate is also highly energetic in nature and leads to the formation of an amorphous film that is more Diamond like in nature [12].…”

“…The three polycrystalline diamond detectors fabricated were labelled Poly-C (with 25 nm C contacts), Poly-C/Ni (with 80 nm C/Ni contacts) and Poly-Pt (with 100 nm Pt contacts) accordingly. After contact deposition the devices were annealed at 600 o C for 10 minutes, to increase electron delocalization through graphitization leading to better electrical properties [12]. This was achieved using a Lenton low pressure furnace operated with 100 sccm of Helium.…”

The origin of the metal enrichment of carbon nanostructures produced by laser ablation of a carbon–nickel target

“…The authors have reported previously significant enhancements in the electrical properties of nanostructured carbon films deposited by laser ablation of mixed C:Ni targets in background pressures of argon gas [1]. Allotropes of carbon formed through cluster assembly [2,3] typically display high porosities and large surface areas [4,5], with sp 3 bond formation at the surface of clusters limiting the conductivity [6], and the observed improvements in electrical characteristics were therefore attributed to a preferential incorporation of Ni in the films and an incongruent transfer of material from target to substrate.…”

“…Here, plumes accompanying ablation of the mixed carbon-nickel target [1] are examined using optical emission spectroscopy and filtered imaging in an attempt to understand the impact on both plume dynamics and sample composition of varying the background gas pressure. While the focus of the current research is primarily to understand the reasons for the high Ni:C ratio, these mixed plumes offer a somewhat unique system for more general studies of plume expansion in inert gases, particularly since C is lighter and Ni heavier than the background gas.…”