Extraordinary growth of C60 on a GaAs(001) As-rich 2×4 surface

Abstract

Dynamic force microscopy study of the Ga-rich c ( 8 × 2 ) and As-rich c ( 4 × 4 ) reconstructions of the GaAs(001) surface Structure and morphology of the As-rich and the stoichiometric GaAs (114)A surface J. Appl. Phys. 95, 7645 (2004); 10.1063/1.1707212Structure and interface composition of Co layers grown on As-rich GaAs(001) c(4×4) surfaces J.We have systematically investigated, by using scanning tunneling microscopy, the adsorption and film growth of C 60 on the various GaAs͑001͒ surface phases prepared by molecular-beam epitaxy. For most phases, the C 60 overlayer exhibits the usual close-packed fcc͑111͒ configuration with its lattice constant close to that of the bulk C 60 crystal. However, in the case of C 60 on the As-rich 2ϫ4 substrate, the epitaxial growth is found to be quite different and unique; C 60 film takes its ͑110͒ crystalline axis; the C 60 overlayer is highly strained with a lattice expansion of ϳ13%, and this structure is very stable at least up to 10 ML. We will address the underlying formation mechanism of this new structure in terms of a charge transfer from the As-dangling bonds to C 60 s and a site-specific C 60 -substrate interaction, as confirmed by molecular dynamic simulations. The present system provides a unique opportunity to study fullerene and/or noble-gas related two-dimensional phenomena, and demonstrates a potential for fabrication of novel fullerene-based devices, such as strained superlattice structures.

Molecular Orientation and Electronic Structure of Epitaxial Bucky Ferrocene (Fe(C60(CH3)5)C5H5) Thin Films

“…14 For example, the lattice of a C 60 film grown on a GaAs(001) substrate can be expanded because of the interfacial strain by as large as 13%. 15 The present result, however, cannot be explained by this mechanism because of the following reasons. If the lattice with an original lattice constant is strained because of the commensuration to the substrate, the lattice constant at the interface must be between the original value and the commensurate value.…”

Growth and characterization of C60/GaAs interfaces and C60 doped GaAs

“…Investigations of C 60 first layer configurations on GaAs (0 0 1) substrates by scanning tunnel microscopy (STM) were reported by Sakurai et al [16,17]. To compare with results of the STM measurements, we investigate the RHEED intensity oscillations of C 60 layer growth on the (2 Â 4) structures of GaAs (0 0 1) substrates [10].…”

“…To compare with results of the STM measurements, we investigate the RHEED intensity oscillations of C 60 layer growth on the (2 Â 4) structures of GaAs (0 0 1) substrates [10]. STM measurements suggest that C 60 molecules are adsorbed in the missing As dimer rows of GaAs (0 0 1) with (2 Â 4)b structure, and the density of the C 60 first layer is estimated to be 50% of the full coverage [16,17]. The RHEED intensity oscillations during the C 60 growth on a GaAs (0 0 1) with (2 Â 4) structure shows that there is a shoulder at 0.5 ML, and intensity peaks appear at 1.5 ML and 2.5 ML, indicating that the density of the adsorption sites on the structure is estimated to be 50% of the full coverage [10].…”

Mechanical and optical characteristics of Al-doped C60 films

“…Early works on the growth of C 60 films have proved that C 60 molecules crystallize in the face-centered cubic crystal on the crystalline substrates such as Si and GaAs [1][2][3][4][5][6]. Indeed, we have successfully grown high-quality single crystalline (1 1 1)-oriented C 60 films on GaAs (0 0 1) and GaAs (1 1 1)B substrates [7].…”