Chemical bonding of fullerene and fluorinated fullerene on bare and hydrogenated diamond

摘要

We investigate the interface between a C-60 fullerite film, C60F36, and diamond (100) by using core-level photoemission spectroscopy, cyclic voltammetry (CV), and high-resolution electron energy loss spectroscopy (HREELS). We show that C-60 can be covolently bonded to reconstructed C(100)-2 x 1 and that the bonded interface is sufficiently robust to exhibit characteristic C-60 redox peaks in solution. The bore diamond surface can be passivated against oxidation and hydrogenation by covalently bound C-60. However, C60F36 is not as stable as C-60 and desorbs below 300 degrees C (the latter species being stable up to 500 degrees C on the diamond surface). Neither C-60 fullerite nor C60F36 form reactive interfaces on the hydrogenated surface-they both desorb below 300 degrees C. The surface transfer doping process of hydrogenated diamond by C60F36 is the most evident one among all the adsorbate systems studied (with a coverage-dependent band bending induced by C60F36).