Micro‐Raman spectroscopic investigations of cobalt phthalocyanine thin films deposited on quartz and diamond substrates

Abstract

In this paper we present study of cobalt phthalocyanine (CoPc) thin films deposited on quartz and diamond substrates. The different diamond substrates were obtained using chemical vapour deposition method (CVD). The micro-Raman scattering spectra of CoPc thin films deposited onto quartz and diamond substrates were investigated in the spectral range 200 -1800 cm -1 at room temperature for different wavelengths excitation (488 nm and 785 nm). The Raman modes A 1g and B 1g are connected with different polymorphic of metallophthalocyanine phase of CoPc thin films deposited on substrates (α and β form). Using confocal and surface Raman mapping we also obtained information on polymorphic phase of CoPc layers deposited on different diamond substrates. We observed both, change and distribution of polymorphic phase of CoPc thin films deposited on the surface. The observed feature can be probably caused by the change of crystalline form of CoPc thin layer and different size of crystallites of the diamond substrates.

The molecular structure ordering and orientation of the metallophthalocyanine CoPc, ZnPc, CuPc, and MgPc thin layers deposited on silicon substrate, as studied by micro-Raman spectroscopy

“…The b angle is calculated from the ratio intensities (I VV /I VH ) for A 1g and B 1g Raman modes of MPcs deposited on solid state substrate. Detailed informations concerning the designation of the orientation of the MPc thin layers using polarized Raman spectra we concluded in the previous works [21,22]. The orientation of MPc's thin layers is closely connected with parameters of the deposition process such as: temperature of the substrate, deposition rate, method of evaporation, and thickness of the obtained thin layers.…”

Effect of annealing temperature on optical and electrical properties of metallophthalocyanine thin films deposited on silicon substrate

“…The position of the most intense band (B 1g Raman mode) is 1542 cm −1 and is associated with the cobalt ion (Co 2+ ) adapted to the phthalocyanine molecule and can be designated by the displacement of C-N-C bridge bonds of molecule macrocycle. From the previous study it is known that for different metal atoms substituted in the center of phthalocyanine the energy of B 1g band is related to the mass of the metal atom, metal ion size and diameter of phthalocyanine cavity [13][14][15]. In Fig.…”

“…The inclination angle of the molecule plane to the substrate plane is calculated from intensities ratio I VV /I VH for B 1g Raman mode achieved from Raman spectra. The detailed description has been given in our previous works [13][14][15]. The angle β is a parameter representing the angle between molecule plane and substrate surface.…”

“…This is probably due to the reorientation of the molecules and alignment of the molecular structure of the organic thin film during long time annealing process. It is known from our previous work that prolonged annealing process causes changes in the polymorphic forms of MPc thin layer structure [14,15]. Using Cheung's functions and thermionic emission theory [23,24] describing the currentvoltage characteristics and the resulting electrical parameters for semiconductors, we calculated electrical parameters of the Au/CoPc/n-Si/Al structure such as series resistance and potential barrier for Au/CoPc/n-Si/Al structure before and after annealing process.…”

Modified Au-Based Nanomaterials Studied by Surface Plasmon Resonance Spectroscopy

“…Four scans on the irradiated regions and two spectra outside the irradiated regions were measured on the same day and analysis conditions, in order to avoid possible errors in the measurements due to aging effects of the CoPcs with time. 23,233 The vibrations of the CoPc planar molecule (a scheme is shown in Figure 7.1), which consists of 57 atoms, can be classified into the following irreducible representation (taking into account only internal vibrations): [234][235][236][237] Γ vibrational = 14A 1g + 13A 2g + 14B 1g + 13E g + 6A 1u + 8A 2u + 7B 1u + 7B 2u + 28E u (7.1) These modes can be divided into three categories: modes active in Raman scattering, modes active in IR spectra and modes that are neither active in Raman nor IR spectra (but these become active in Raman, as a result of an interaction with the support, if a distortion of the molecular symmetry occurs). The basic Raman selection rules allow A 1g , B 1g , B 2g , and E g modes in the normal Raman scattering.…”