Adsorption of C82 on Si(100)

Abstract

The interactions between C 82 molecules and the Si (100) surface have been explored via ab-initio total energy calculations. Configurations which have the cage located within the dimer trench bonded to four dimers (t4) and upon the dimer row bonded to two dimers (r2) have been investigated, as these were found to be most stable for the C 60 molecule. It is found that the interactions between the surface and the C 82 molecule are weaker than for the corresponding configurations for C 60 . The C 82 cage has a far lower symmetry than the C 60 cage and this gives many more unique rotational orientations of C 82 compared with C 60 . We have thus investigated the binding energy when the local area of the C 82 binding to the surface is the same but the cage orientation varies. We show that the binding energy can vary strongly within the configurations investigated. Bader analysis has been used to explain the relative binding energies of the different configurations.

Adsorption of N@C60 on Si(100)

“…When analysing the bonding within the lower part of the fullerene cage (the region which bonds to the silicon surface), our results compare favourably with those by Frangou et al [22]. The carbon-carbon bonds for the carbon atoms that form the carbon-silicon bonds have all decreased bond ratios (see Figure 3), which results from the formation of the carbon-silicon bonds.…”

“…We denote these basis sets as triple numeric with double polarisation (TNDP). Using basis sets of the TNDP level of completeness has been shown [22] to reduce the basis set superposition error (BSSE), without the need to correct the results via the the Boys and Bernardi counterpoise method [23].…”

“…Table 1 Binding energies of the C 60 molecule on the Si(100) surface in eV. For comparison, the results of previous calculations [16,22] are given. The results using SIESTA include the Boys-Bernardi correction [23].…”

“…Rank SIESTA [16] Frangou [22] C60 N@C60 11 t4i r2e t4d t4i 12 r2e t4h r2e r2e 13 r2g r2g r2g r2g 14 r2d r2d r2d r2d Table 2 The fourteen configurations investigated here are placed in the table above in descending order of stability.…”

Plato: A localised orbital based density functional theory code

“…Plato was used in the first ab-initio studies of the bonding of C 60 molecules to the Si (100) surface that allowed for atomic relaxation [44,45]. Subsequently it has been used to study the adhesion of C 82 molecules and endohedral C 60 molecules and the interaction between C 60 molecules on the Si (100) surface [46,47,48]. In these studies TNDP basis sets were employed, which massively reduced the basis set superposition error to the point where such corrections were unnecessary.…”