Raman spectroscopy is a most often used standard technique for characterization of different carbon materials. In this work we present the Raman spectra of polycrystalline diamond layers of different quality, synthesized by Hot Filament Chemical Vapor Deposition method (HF CVD). We show how to use Raman spectroscopy for the analysis of the Raman bands to determine the structure of diamond films as well as the structure of amorphous carbon admixture. Raman spectroscopy has become an important technique for the analysis of CVD diamond films. The first-order diamond Raman peak at ca. 1332 cm −1 is an unambiguous evidence for the presence of diamond phase in the deposited layer. However, the existence of non-diamond carbon components in a CVD diamond layer produces several overlapping peaks in the same wavenumber region as the first order diamond peak. The intensities, wavenumber, full width at half maximum (FWHM) of these bands are dependent on quality of diamond layer which is dependent on the deposition conditions. The aim of the present work is to relate the features of diamond Raman spectra to the features of Raman spectra of non-diamond phase admixture and occurrence of other carbon structures in the obtained diamond thin films.
In this article, we present orientation study of metallophthalocyanine (MPcs) (CoPc, ZnPc, CuPc, and MgPc) thin films deposited on silicon substrate. The MPc's thin layers were obtained by the quasi-molecular beam evaporation. The micro-Raman scattering spectra of MPc's thin films were investigated in the spectral range 550-1650 cm -1 using 488 nm excitation wavelength. Raman scattering studies were performed at room temperature before and after annealing process. Annealing process of thin layers was carried out at 200°C for 6 h. From polarized Raman spectra using surface Raman mapping, the information on polymorphic phase of MPc's layers has been obtained. The chosen Raman modes A 1g and B 1g are connected with different polymorphic phases of MPc (a and b form) thin layers. Moreover, the obtained results showed the influence of the annealing process on the ordering of the molecular structure. Following the annealing process, it was observed arrangement of the thin layers structure being revealed in Raman spectra. The obtained results indicate that the annealing process has a significant influence on the structure of thin layers being under study.
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 presented article concerns the comparison between two different zinc-oxide structures - bulk crystals and polycrystalline thin films. Bulk crystals were grown by a Bridgman method. For thin-film production, a sol-gel spin-coated method was chosen. A part of thin layers samples was annealed in 600 $$^{o}$$
o
C to induce recrystallization. The morphological and structural properties of all samples were investigated using various microscopy techniques, X-ray diffraction, and Raman spectroscopy. Confocal and scanning electron microscopy, as well as XRD, was used to estimate the influence of the recrystallization process on the morphology of the samples. The Raman vibrations in different scattering geometries were determined using polarized Raman spectra. What is more, in the case of the non-annealed sol-gel layer, the localized reorientation of crystallites was observed, using Raman microscopy. The morphology of the samples was compared to their optical properties, which were investigated by exploiting UV-Vis absorption and photoluminescence spectroscopy. Absorption spectroscopy allowed us to estimate the energy bandgap for different types of ZnO layers and to compare the values obtained for the ZnO crystal structure obtained by the Bridgman method. The photoluminescence and Raman spectroscopy were used to determine the possible defects correlated with the growth conditions.
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