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

We investigate the interface between a C(60) fullerite film, C(60)F(36), 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, C(60)F(36) 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 C(60)F(36) form reactive interfaces on the hydrogenated surface-they both desorb below 300 degrees C. The surface transfer doping process of hydrogenated diamond by C(60)F(36) is the most evident one among all the adsorbate systems studied (with a coverage-dependent band bending induced by C(60)F(36)).