HIGH-RESOLUTION ELECTRON-ENERGY-LOSS SPECTROSCOPY OF CHLOROALUMINUM PHTHALOCYANINE ULTRATHIN FILMS

High-resolution electron energy loss spectra (HREELS) were measured fo r ultrathin films of chloroaluminum phthalocyanine (ClAlPc) deposited on a cleaved HOPG surface in order to investigate the molecular orient ation and its thickness dependence. It was found that for the monolaye r film ClAlPe molecules lie flat on the HOPG surface without heat trea tment. With increase in the film thickness, the molecules become orien ted at a tilt. The result show a marked difference from the orientatio n of ClAlPc molecules on MoS2, where the molecules lie tilt on MoS2 in the as-grown monolayer. (C) 1998 Elsevier Science B.V.