Wang, Z., Zhang, Z., Zhang, R. et al. Chin. Sci. Bull. (2012) 57: 3556. doi:10.1007/s11434-012-5397-3
We developed a cluster ion beam system that produces negative cluster beams of C1–C10 with ion current of 4.5 nA-50 μA at extraction voltages ranging from 6 to 20 kV. The system uses the injector of a tandetron accelerator and was established by inserting an electrostatic scanner on its ion-optical line and modifying its Faraday cup into a substrate holder. Utilization of clusters enables ultrashallow ion implantation at energies as low as 600 eV/atom without deceleration. Small carbon clusters C2 and C4 were implanted into Ni/SiO2/Si substrates and following post-thermal treatment graphene was obtained. Raman spectroscopy showed characteristic 2D peaks with G-to-2D peak ratios revealing formation of 2–3 layers of graphene. The Raman data reveals clear effect of nonlinear cluster-surface interaction in ion beam synthesis of two-dimensional nanomaterials.
ultralow energy cluster beam negative ion ultrashallow implantation grapheme Raman scattering