Atomic layer fluorination of highly oriented pyrolytic graphite using hyperthermal atomic fluorine beam

Tagawa, Masahito*; Yokota, Kumiko*; Maeda, Kenichi*; Yoshigoe, Akitaka ; Teraoka, Yuden

Hyperthermal (kinetic energy of 10 eV) fluorine atom beam interaction with highly oriented pyrolytic graphite (HOPG) was studied. Surface analytical results of atomic fluorine-exposed HOPG using synchrotron radiation photoelectron spectroscopy showed that the fluorine reaction was limited at the topmost HOPG(0001) layer. This is due to the fact that the kinetic energy of 10 eV is not sufficient to penetrate graphite layer but is enough for breaking C-C bonds and forms CF and CF functional groups through the beam-induced fluorination reactions. It was demonstrated that the use of hyperthermal energy in the range of 10 eV is advantageous for damage-free modification of the topmost surface of carbon-based materials.