Characterization of thin films of chloroaluminum phthalocyanine on MoS2:: HREELS, LEET and PIES study

High-resolution electron energy loss spectra (HREELS), low-energy electron transmission spectra (LEET) and Penning ionization electron spectra (PIES) were measured for thin films of chloroaluminum phthalocyanine (ClAlPc) deposited on a cleaved MoS2 surface in order to investigate the molecular orientation and aggregation in the monolayer range. It was found that the as-grown film of monolayer equivalence consists of ClAlPc islands and the substrate surface is not fully covered by the molecules. Upon heating the film, the molecules spread over the substrate surface to form a uniform monolayer with a flat-he orientation, where the Cl atoms protrude outside the film. (C) 1998 Elsevier Science S.A. All rights reserved.