Structural Investigation of Copper Phthalocyanine Thin Films Using X-Ray Diffraction, Raman Scattering and Optical Absorption Measurements

Abstract

Structural properties of copper phthalocyanine (CuPc) powder and its thin films coated on glass plate are investigated using X-ray diffraction, Raman scattering and optical absorption techniques. These experiments are carried out at room temperature on CuPc powder and as-coated, 320 C and 520 C annealed, CuPc thin films. From the X-ray diffraction (XRD), we find that the CuPc powder exists in monoclinic phase, as-coated film is in orthorhombic a-phase and the film annealed at 320 C exists in monoclinic b-phase with different lattice parameters as compared to those of the powder phase. The XRD peaks in 520 C annealed film do not show the presence of CuPc but indicate the presence of copper oxide (CuO) nanoclusters of approximately 15 nm size. The optical Raman phonon frequencies of CuPc powder, as-coated and 320 C annealed CuPc films show a slight shift in the intramolecular high frequency modes. Whereas, their low frequency Raman spectra from intermolecular modes are characteristically different indicating different phases. The different characteristic behavior of the optical absorption spectra of the as-coated and 320 C annealed CuPc films corroborate the structural changes in the annealed film.

Controllable preparation of copper phthalocyanine single crystal nano column and its chlorine gas sensing properties

“…[16][17][18] The high frequency Raman of phthalocyanine molecule has been widely investigated. [18][19][20] The low frequency region, which are generally weak and clearly characteristic of the lattice vibration and can be used as a fingerprint of the crystal structure, particularly the terahertz band (THz), 21 however, was no enough discussion. In order to observe different behaviors in the terahertz band breathing mode of CuPc nano column under different growth time, low frequency Raman spectra were recorded and shown in Figure 4(b).…”

“…FWHM of the peaks were smaller than that reported in the Ref. 20, respectively. They indicate that the crystalline qualities of the nano columns are better than that vacuum deposited film.…”

Giant spin and orbital moment anisotropies of a Cu-phthalocyanine monolayer

“…34 Consistently with previous reports, [35][36][37] the XAS of CuPc, shown in Fig. 2͑a͒, feature two main lines separated by about 20 eV, reflecting the transitions from the Cu 2p 1/2,3/2 manifolds into an empty orbital with predominant 3d x 2 −y 2 character.…”

Dissolution of copper phthalocyanine and fabrication of its nano-structure film

“…The thread-like nanobelts with diameters between 100 nm and 200 nm are packed in high density and form network structure. There are lots of reports about the crystal structures of CuPc films [18][19][20] . The most common structures are designated as α and β phases which both are stable at low temperatures.…”

“…The most common structures are designated as α and β phases which both are stable at low temperatures. The α phase of CuPc film would transform into β phase after being annealed [19,20] . The X-ray diffraction pattern of CuPc film fabricated by EPD is shown in Figure 6.…”