The titanyl phthalocyanine (TiOPc) thin film deposited on glass, silicon and gold substrate have been studied using Raman spectroscopy, atomic force microscopy (AFM), absorption and profilometry ...measurements. The TiOPc thin layers have been deposited at room temperature by the quasi-molecular beam evaporation technique. The Raman spectra have been recorded using micro Raman system equipped with a confocal microscope. Using surface Raman mapping techni que with polarized Raman spectra the polymorphic forms of the TiOPc thin films distribution have been obtained. The AFM height and phase image were examined in order to find surface features and morphology of the thin films. Additionally to compare experimental results, structure optimization and vibrational spectra calculation of single TiOPc molecule were performed using DFT calculations. The received results showed that the parameters like polymorphic form, grain size, roughness of the surface in TiOPc thin films can well characterize the obtained organic thin films structures in terms of their use in optoelectronics and photovoltaics devices.
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•DFT calculations were performed for single molecule of TiOPc.•The polymorphic form, grain size and roughness of the surface was estimated.•Energy gap Eg and doping energy Ed for phthalocyanine thin film were estimated.
Organic surfaces play a major role in materials science. Most surfaces that we touch in our daily lives are made from organic materials, e.g., vegetables, fruit, skin, wood, and textiles made from ...natural fibers. In the context of biology, organic surfaces play a prominent role too, proteins docking onto cell surfaces are a good example. To better understand the characteristics of organic surfaces, including physico-chemical properties like wettability or chemical reactivities and physical properties like friction and lubrication, a structurally well-defined model system that can be investigated with numerous analytical techniques is desirable. In the last two decades, one particular system, self-assembled monolayers or SAMs, have demonstrated their suitability for this purpose. In particular, organothiols consisting of an organic molecule with an attached SH-group are well suited to fabricating structurally well-defined adlayers of monolayer thickness on gold substrates using a simple preparation procedure. These ultrathin monolayers expose an organic surface with properties that can be tailored by varying the type of organothiol employed. After a short introduction into the preparation of SAMs, this article provides an overview of the possibilities and limitations of organic surfaces exposed by Au-thiolate SAMs. Applications are as diverse as the metallization of organic surfaces, a fundamental problem in materials science, and the fabrication of surfaces that resist the adsorption of proteins. In addition to a number of different case studies, we will also discuss the most powerful analytical techniques needed to characterize these important model systems.
•DAP, TAE, and PETA were photo-polymerized to thin-layers on PET fibers.•Charge storage effects were observed in poly-TAE and poly-PETA.•Poly-TAE thin-layers held 1/e of the initial charge for more ...than 10min.•The charge decay times increased with increasing UV exposure during polymerization.•No charge storage was observed in poly-DAP due to water absorption by carboxylic groups.
The scope of the reported experiments was to study the charging behavior of photo-polymerized poly-DAP, poly-TAE and poly-PETA thin-layers, namely the remanence or storage of artificially deposited electric charges. The thin-layers were polymerized on the fibers of a technical non-woven under variation of the main parameters of the polymerization process, namely the monomer concentration in the applied precursor and the duration of UV exposure. The charging behavior of the layers was characterized by recording the charge dissipation after defined surface charging by a corona discharge. After the artificial charging, the electric field generated by residual surface charges was measured using an electric field mill as a function of time. It was found that the poly-DAP thin-layer showed no improvement in charge decay over the untreated sample. This is attributed to water absorption due to carboxylic groups. Poly-TAE and poly-PETA showed significant increases in charge remanence with increasing polymerization. It is proposed that the observed change in the electric property is related to increased cross-linking and reduced chain mobility with increasing UV exposure. Best results were achieved with poly-TAE holding, a thin-layer holding 1/e of the initial charge after more than 10min.
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•Semi-conducting polymer based on distyryl-bithiophene π-conjugated system.•Synthesis, structural, thermal, morphological and electrochemical characterization.•Absorption and ...photoluminescence properties in dilute solution and as thin solid film.•Electrical characteristic modeled by the current space-charge-limited mechanism.•Yellow-green electroluminescence from multilayer organic light-emitting diode.
A semi-conducting polymer, P-DSBT, based on distyryl-bithiophene π-conjugated sequences has been synthesized and characterized. The macromolecular material was soluble in volatile solvents and showed a good film quality; it exhibited an amorphous morphology with relatively high glass transition temperature. The absorption and photoluminescence properties of the polymer were studied in solution and as thin solid film, which showed an optical gap of 2.6eV. The HOMO/LUMO energy levels were evaluated by cyclic voltammetry measurements and indicate a p-type semi-conducting material. The electrical properties of P-DSBT were investigated by the current-tension characteristic and modeled by the current space-charge-limited (SCLC) mechanism; charge carrier mobility higher than 10−6cm2V−1s−1 was evaluated. A yellow-green electroluminescence was evidenced in a multilayer organic light-emitting diode with an ITO/PEDOT:PPS/P-DSBT/BCP/Al configuration.
A series of bis(phenylvinyl)anthracene-based polymers containing different lengths of polar ethylene glycol groups in the main chain (P1–3) were efficiently synthesized by Wittig polycondensation. ...These polymers are fully soluble in volatile solvents, which helped a lot to obtain high quality films. Moreover, these semi-conducting materials exhibited semi-crystalline morphology with relatively high glass transition temperature. In this article, the UV–visible absorption and fluorescence properties of P1–3 were studied consequently both in solution and as thin solid film: tan absorption-onset at 433 nm was observed and all these bis(phenylvinyl)anthracene-based polymers (P1–3) show a blue emission in solution, fluorescence quantum efficiencies being respectively 52% for P1, 75% for P2 and 67% for P3. In addition, the HOMO/LUMO energy levels were evaluated by cyclic voltammetry measurements and indicate a p-type semi-conducting materials. Finally, the electrical properties of P1–3 were investigated by recording current-tension characteristics and these experimental results were modeled by the current space-charge-limited (SCLC) mechanism.
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•Synthesis of new bis(phenylvinyl)anthracene-based Polymers containing polar spacer group with different size.•Good film quality.•Semi-conducting polymers.•Spacer groups effect on optical and electrical properties.•Good PL quantum yield.
