Studies on structure and Raman spectroscopy of Ni-doped copper phthalocyanine thin films

Ni-doped copper phthalocyanine (CuPc) organic films with different mixing ratios were prepared in high vacuum (HV) chamber. The results of AFM, XRD, UV-vis and Raman spectroscopy indicated that the surface morphologies of the films were found to be flater and the structures of the CuPc films still kept their original alpha-phase crystal, with only the crystallinity or crystallite sizes being changed and the versatile structure or charge transport being modified with the increase of Ni-doping ratios. Moreover, 514 nm-visible-light-excited normal Raman spectra (NRS), 325 nm-ultraviolet-excited and 633 nm-excited resonance Raman spectra (RRS) were analyzed by comparison and by density functional theory (DFT) calculations of the amorphous nickel atoms clusters, confirming that there were no chemical changes between CuPc molecules and nickel atoms; and the amorphous nickel atoms clusters had a noticeable light absorption loss, offering us an insightful structural understanding of the Raman effect of the different concentrations of Ni-doped CuPc films. (C) 2014 Elsevier B.V. All rights reserved.