High temperature study of FT-IR and Raman scattering spectra of vacuum deposited CuPc thin films

In this work we present the polarized and nonpolarized Raman spectra of copper phthalocyanine CuPc layers deposited on (001)Si and borosilicate glass substrates. These spectra are compared with FT-IR spectra of CuPc molecules in KBr pellets and thin layers of CuPc on (001)Si substrates obtained by thermal evaporation method. The observed Raman and FT-IR bands are assigned to definite phonon modes on the basis of their symmetry and comparison with the frequencies predicted by lattice dynamical calculations (LDC). The films of CuPc grown on Si substrate show very good out-of-plane ordering and have X-ray rocking widths of around 0.038. For layers grown at different temperatures of substrate, we found a change of the molecular out-of-plane tilt angle, as obtained from Raman scattering. Observed feature is accompanied by a change of the out-of-plane lattice parameter. q 2004 Elsevier B.V. All rights reserved. PACS: 78.55.Kz; 78.66.Qn; 71.70.FK