Synthesis, electrochemical and spectroelectrochemical properties of novel phthalocyanine complexes of manganese, titanium and indium

Analysis of a Flexible Photoconductor, Manufactured with Organic Semiconductor Films

This work presents the evaluation of the electrical behavior of a flexible photoconductor with a planar heterojunction architecture made up of organic semiconductor films deposited by high vacuum evaporation. The heterojunction was characterized in its morphology and mechanical properties by scanning electron microscopy and atomic force microscopy. The electrical characterization was carried out through the approximations of ohmic and SCLC (Space-Charge Limited Current) behaviors using experimental J-V (current density-voltage) curves at different voltages and under different light conditions. The optimization of the photoconductor was carried out through annealing and accelerated lighting processes. With these treatments, the Knoop Hardness of the flexible photoconductor has reached a value of 8 with a tensile strength of 5.7 MPa. The ohmic and SCLC approximations demonstrate that the unannealed device has an ohmic behavior, whereas the annealed device has an SCLC behavior, and after the optimization process, an ohmic behavior and a maximum current density of 0.34 mA/mm2 were obtained under blue light. The approximations of the device's electron mobility (μn) and free carrier density (n0) were performed under different light conditions, and the electrical activation energy and electrical gap were obtained for the flexible organic device, resulting in appropriate properties for these applications.

MnPc Films Deposited by Ultrasonic Spray Pyrolysis at Low Temperatures: Optical, Morphological and Structural Properties

In this work, we report how manganese phthalocyanine (MnPc) films obtained using the ultrasonic spray-pyrolysis technique at 40 °C deposited on glass substrate subjected to thermal annealing at 100 °C and 120 °C. The MnPc films were characterized using UV/Vis spectroscopy, Raman spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The absorption spectra of the MnPc films were studied in a wavelength range from 200 to 850 nm, where the characteristic bands of a metallic phthalocyanine known as B and Q bands were observed in this range of the spectrum. The optical energy band (Eg) was calculated using the Tauc equation. It was found that, for these MnPc films, the Eg has the values of 4.41, 4.46, and 3.58 eV corresponded to when they were deposited, annealing at 100 °C and 120 °C, respectively. The Raman spectra of the films showed the characteristic vibrational modes of the MnPc films. In the X-Ray diffractograms of these films, the characteristic diffraction peaks of a metallic phthalocyanine are observed, presenting a monoclinic phase. The SEM images of these films were studied in a cross-section obtaining thicknesses of 2 μm for the deposited film and 1.2 μm and 0.3 μm for the annealed films at 100 °C and 120 °C. Additionally, in the SEM images of these films, average particle sizes ranging from 4 to 0.041 µm were obtained. The results agree with those reported in the literature for MnPc films deposited by performing other techniques.

Synthesis and photovoltaic properties of novel ferrocene-substituted metallophthalocyanines

In this paper, a series of new metallophthalocyanines, including ferrocene groups, were designed, synthesized and, characterized, and their photovoltaic properties were investigated as alternative electron-donor materials in bulk heterojunction (BHJ) solar cells. These products were synthesized by a Sonogashira cross-coupling reaction between tetraiodophthalocyanine and ethynyl ferrocene. The newly synthesized phthalocyanines (4-6) were characterized by FT-IR, UV-Vis, ¹H NMR, and MALDI-TOF spectroscopic methods and elemental analysis. The electrochemical characterizations were carried out by cyclic voltammetry as well as differential pulse voltammetry. Density functional theory calculations were realized to prove the charge separation between ferrocene as an electron-donor and the phthalocyanine ring as an acceptor. According to UV-Vis measurements, a 25 nm red-shift was observed for complex 4 compared with complexes 5 and 6. Finally, the photovoltaic performance of these compounds used as an electron-donor moiety in a BHJ device were investigated. A function of different blend ratios was tested by fabricating a series of BHJ devices with the architecture of FTO/PEDOT:PSS/4-6: PCBM blend/Ag with an identical thickness of the active layer. The results indicated that the photovoltaic conversion efficiency of BHJ devices exhibited a strong blend-ratio dependence. The maximum power conversion efficiency was obtained by 5-based devices, as 3.65%, with a blend ratio of 1.5 : 1.0 under standard AM 1.5 illumination.

Highly improved photoreduction of carbon dioxide to methanol using cobalt phthalocyanine grafted to graphitic carbon nitride as photocatalyst under visible light irradiation

A substantially improved methanol yield was achieved from the photoreduction of carbon dioxide under visible light by using a hybrid photocatalyst consisting of molecular cobalt phthalocyanine tetracarboxylic acid (CoPc-COOH) complex immobilized to the organic semiconductor graphitic carbon nitride (g-C₃N₄) and triethylamine as sacrificial electron donor. The structural and morphological features of the hybrid photocatalyst determined by various techniques like FTIR, UV-Vis, Raman, XPS, TGA, BET etc. After 24 h of light irradiation, the methanol yield by using g-C₃N₄/CoPc-COOH photocatalyst (50 mg) was found to be 646.5 µmol g^-1cat or 12.9 mmol g^-1cat with conversion rate 538.75 µmol h^-1 g^-1cat. However, the use of homogeneous CoPc-COOH (6.5 µmol Co, equivalent to g-C₃N₄/CoPc-COOH) and g-C₃N₄ (50 mg) provided 88.5 μmol (1770 μmol g^-1cat) and 59.2 μmol (1184 μmol g^-1cat) yield of methanol, respectively under identical conditions. The improved photocatalytic efficiency of the hybrid was attributed to the binding ability of CoPc-COOH to CO₂ that provided the higher CO₂ concentration on the support. Further, the semiconductor support provided better electron mobility and charge separation with the integrated benefit of facile recovery and recycling of the material at the end of the reduction process.

Novel indium(iii) phthalocyanines; synthesis, photophysical and humidity sensing properties

Novel indium(iii) phthalocyanines were synthesized. Photophysical properties and the humidity detection capabilities of their films have also been investigated.

An effect of the substituent position and metal type on the electropolymerization properties of chalcone substituted metallophthalocyanines

Cobalt(ii) and manganese(iii) phthalocyanines bearing peripherally and non-peripherally tetra substituted {(2E)-3-[4-(dimethylamino)phenyl]prop-2-enoyl}phenoxy groups were synthesized by cyclotetramerization of the phthalonitrile derivatives and their electrochemical properties were examined using CV and SWV techniques for the first time.