STM/STS study of C$_{60}$F$_{36}$ molecules adsorption on $7\times 7$–Si(111) surface

Spatially resolved images of an individual C$_{60}$F$_{36}$ fluorofullerene molecules on Si(111)–$7 \times 7$ surface have been obtained by means of scanning tunneling microscopy/spectroscopy (STM/STS). The presence of isomers with different symmetry ($T$, $C_3$, $C_1$) has been revealed in STM investigation of initial adsorption stage of C$_{60}$F$_{36}$ on silicon surface Si(111)–$(7\times7)$. The adsorbed fluorofullerene molecule can occupy any adsorption site of silicon surface (corner site, faulted half, unfaulted half) that indicates for strong molecule-substrate interaction. The HOMO–LUMO gap of the adsorbed C$_{60}$F$_{36}$ molecules have been estimated from current image tunneling spectroscopy (CITS) and $z(V)$ with engaged feedback measurements. The value of HOMO–LUMO gap observed experimentally was $3$ eV. The C$_{60}$F$_{36}$ molecules adsorption on Si(111)–$(7\times7)$ surface was stable and kept equilibrium configuration during several hours.