The phototransformation of C60 thin films on GaAs(100) studied by in situ Raman spectroscopy

Abstract

Raman spectra in the region of the pentagonal pinch mode A g (2) of C 60 were taken in situ during the deposition of C 60 on the GaAs͑100͒ surface at different temperatures. For very low coverages, only the feature corresponding to the pentagonal pinch mode of pristine C 60 is visible. The onset of polymerization under laser irradiation occurred at thicknesses of about 15 nm which is attributed to a suppressive effect on the polymerization process due to the interaction of C 60 with the substrate surface. The line shape for the feature due to photopolymerized C 60 was different at each temperature indicating distinct polymeric states at different temperatures. These different states are discussed in comparison to recent theoretical calculations. Additionally, the photopolymerization due to irradiation after growth was investigated in situ.

Substrate Templating Guides the Photoinduced Reaction of C60 on Calcite

“…This well-known reaction has been widely studied in bulk C 60 [16,17] and in C 60 thin films on metal substrates, [18,19] and it is known to result in a twodimensional hexa-polymer in the bulk. We deposit C 60 molecules onto the (10.4) cleavage plane of calcite (CaCO 3 ), which is a bulk insulator.…”

Photoactivable Nonsymmetrical Bifunctional Linkers for Protein Immobilization on Attenuated Total Reflectance FTIR Optical Devices

“…In this study, we induce non‐thermal [2+2] cycloaddition by irradiation of C 60 fullerenes. This well‐known reaction has been widely studied in bulk C 60 16, 17 and in C 60 thin films on metal substrates,18, 19 and it is known to result in a two‐dimensional hexa‐polymer in the bulk. We deposit C 60 molecules onto the (10.4) cleavage plane of calcite (CaCO 3 ), which is a bulk insulator 20.…”

Raman Studies of Molecular Thin Films

“…Additional experiments were also performed for C 60 deposition on GaAs [19,20]. While the behaviour is in general very similar, the remarkable difference between the initial stages of C 60 deposition on Si(100) and GaAs(100) is the fact, that the Raman peak of the unpolymerized C 60 appears earlier and stronger on the GaAs substrate as compared to the Si substrate.…”