Activity: Talks and presentations › Conference presentations
We study possible fragmentation effects that can occur during the transfer of C60 molecules in vacuum by matrix assisted pulsed laser evaporation (MAPLE). The MAPLE studies are performed on a frozen homogeneous dilute solution of C60 in anisole (typically 0.67 wt.%), and over a broad range of laser fluences, from 0.3 Jcm-2 up to 2 Jcm-2. The processing of the C60 molecules into thin films of C60, and for other fullerenes can be of large interest not only for fundamental studies, but also for organic
solar cells applications.For a given MAPLE matrix, possible fragmentation effects were monitored by
measuring the deposition rate/pulse and determining the fragmentation rate with matrix assisted laser desorption ionization (MALDI). Analyses of high-resolution SEM images reveal that the surface of the MAPLE films consists of a high density area of clusters/droplets. These round shaped features are probably caused by ejection of large liquid droplets of C60 suspended in solvent upon laser irradiation, followed by the evaporation of the solvent when reaching the substrate. MALDI analyses of the C60 layers deposited onto Si wafers have shown that a significant fraction of fullerenes remain intact upon MAPLE transfer.