M. Szybowicz
Poznan University of Technology, Technical Physics, Faculty Member
The cobalt phthalocyanine (CoPc) thin films (300 nm thick) deposited on n-type silicon substrate have been studied using micro-Raman spectroscopy, atomic force spectroscopy (AFM) and I-V measurement. The CoPc thin layers have been... more
The cobalt phthalocyanine (CoPc) thin films (300 nm thick) deposited on n-type silicon substrate have been studied using micro-Raman spectroscopy, atomic force spectroscopy (AFM) and I-V measurement. The CoPc thin layers have been deposited at room temperature by the quasi-molecular beam evaporation technique. The micro-Raman spectra of CoPc thin films have been recorded in the spectral range of 1000 cm-1 to 1900 cm-1 using 488 nm excitation wavelength. Moreover, using surface Raman mapping it was possible to obtain information about polymorphic forms distribution (before and after annealing) of metallophthalocyanine (α and β form) from polarized Raman spectra. The I-V characteristics of the Au/CoPc/n-Si/Al Schottky barrier were also investigated. The obtained results showed that influence of the annealing process plays a crucial role in the ordering and electrical conductivity of the molecular structure of CoPc thin films deposited on n-type silicon substrate.
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In this work indigo samples from three different sources are studied by using Raman spectroscopy: the synthetic pigment and pigments from the woad (Isatis tinctoria) and the indigo plant (Indigofera tinctoria). 21 samples were obtained... more
In this work indigo samples from three different sources are studied by using Raman spectroscopy: the synthetic pigment and pigments from the woad (Isatis tinctoria) and the indigo plant (Indigofera tinctoria). 21 samples were obtained from 8 suppliers; for each sample 5 Raman spectra were recorded and used for further chemometrical analysis. Principal components analysis (PCA) was performed as data reduction method before applying hierarchical cluster analysis. Linear discriminant analysis (LDA) was implemented as a non-hierarchical supervised pattern recognition method to build a classification model. In order to avoid broad-shaped interferences from the fluorescence background, the influence of 1st and 2nd derivatives on the classification was studied by using cross-validation. Although chemically identical, it is shown that Raman spectroscopy in combination with suitable chemometric methods has the potential to discriminate between synthetic and natural indigo samples.
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... Ke Yang, Srinivasan Balasubramanian, Xiaogong Wang, Jayant Kumar, Sukant Tripathy 3348 Effect of well number on organic multiple-quantum-well electroluminescent device characteristics ... LV Dao, MB Johnston, M. Gal, L. Fu, HH Tan, C.... more
... Ke Yang, Srinivasan Balasubramanian, Xiaogong Wang, Jayant Kumar, Sukant Tripathy 3348 Effect of well number on organic multiple-quantum-well electroluminescent device characteristics ... LV Dao, MB Johnston, M. Gal, L. Fu, HH Tan, C. Jagadish ...
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Titanium, Mathematical Sciences, Applied, Thin Film, Physical sciences, and 13 moreZinc, Phase transition, Free Energy, Heat Capacity, Spectrum, Cross Section, Thermal Properties, Experimental Data, Thermodynamic Properties, Equation of State, Linear System and Response, Two Photon Absorption, and Elastic Constant
Graphene devices require electric contacts with metals, particularly with gold. Scanning tunneling spectroscopy studies of electron local density of states performed on mono-, bi- and tri- graphene layer deposited on metallic conductive... more
Graphene devices require electric contacts with metals, particularly with gold. Scanning tunneling spectroscopy studies of electron local density of states performed on mono-, bi- and tri- graphene layer deposited on metallic conductive Au/Cr/SiO2/Si substrate shows that gold substrate causes the Fermi level shift downwards which means that holes are donated by metal substrate to graphene which becomes p-type doped. These
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ABSTRACT
Experimental results of tunneling and Raman scattering of the high-Tc superconductor Bi2Sr2 CaCu2 O8 (BSCCO) are reported. Tunneling T-dependent conductance G(V,T) of evaporated Pb junctions on cleaved ab planes of the BSCCO (2:2:1:2)... more
Experimental results of tunneling and Raman scattering of the high-Tc superconductor Bi2Sr2 CaCu2 O8 (BSCCO) are reported. Tunneling T-dependent conductance G(V,T) of evaporated Pb junctions on cleaved ab planes of the BSCCO (2:2:1:2) crystals is presented. We obtained a large energy gap, approximately (Delta) equals 26 meV at 4.2 K or 2(Delta) /kBTc equals 6.7. Temperature dependences of tunneling characteristics
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This paper presents results of investigation of photoluminescence (PL) and cathodoluminescence (CL) as well as Raman scattering in Zn1-xMgxSe mixed crystals grown by high pressure Bridgman method for 0 less than x less than 0.615. The... more
This paper presents results of investigation of photoluminescence (PL) and cathodoluminescence (CL) as well as Raman scattering in Zn1-xMgxSe mixed crystals grown by high pressure Bridgman method for 0 less than x less than 0.615. The crystals exhibit yellow-green and blue luminescence from 40 K up to room temperature. The intensity ratio of 'blue' band to the deep levels band
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Diamond micro and nanocrystals continue to receive much attention due to unique optical and electronic properties that are dependent on a variety of material properties, such as size, shape, and composition. The electrical and optical... more
Diamond micro and nanocrystals continue to receive much attention due to unique optical and electronic properties that are dependent on a variety of material properties, such as size, shape, and composition. The electrical and optical properties of nanodiamonds and diamond-like carbon (DLC) are directly related to their structure, such as the types of different possible carbon sp2 and sp3 bonding
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The orientational behavior of liquid crystals from homologous series of 4-cyanophenyl-4′-n-alkylbenzoate (CnH2n+1PhCOOPhCN) doped with dichroic dyes was investigated by means of optical spectroscopy methods: electronic absorption and... more
The orientational behavior of liquid crystals from homologous series of 4-cyanophenyl-4′-n-alkylbenzoate (CnH2n+1PhCOOPhCN) doped with dichroic dyes was investigated by means of optical spectroscopy methods: electronic absorption and fluorescence. The absorption and emission spectra of linearly polarized light were recorded as a function of temperature in whole range of the mesophase. The second- and fourth-rank order parameters (<P2>, <P4>) and molecular
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Biomedical Engineering, Calcium, Scanning Electron Microscopy, Humans, Calcium Phosphates, and 10 moreFourier transform infrared spectroscopy, Surface Properties, Phosphates, Molecular weight, Durapatite, Polyesters, Biocompatible Materials, Hydrogen-Ion Concentration, Body Fluids, and Static Electricity
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Double-walled carbon nanotubes were synthesized by a carbon arc discharge using Fe catalyst. Electron microscopy revealed that the dominant fraction of nanotubes appears in bundles and has outer diameters between 2.5 and 4.0 nm. The... more
Double-walled carbon nanotubes were synthesized by a carbon arc discharge using Fe catalyst. Electron microscopy revealed that the dominant fraction of nanotubes appears in bundles and has outer diameters between 2.5 and 4.0 nm. The by-products (catalyst particles and amorphous carbon) were readily removed using diluted nitric acid. The success of the purification was tracked by electron microscopy and X-ray photoelectron spectroscopy. The surface of purified nanotubes was found to be covalently functionalized with carbonyl-containing groups, which were subsequently removed by thermal annealing. The developed synthesis route has high selectivity for double-walled carbon nanotubes and uses simple starting materials.