Code: MP26	Time Slot/Poster Number: 064	Session: Molecular Electronics and Polymers
Layer-by-Layer Hybrid Films of Polyaniline and Hexaniobate Nanosheets Characterized by Resonance Raman Spectroscopy
Claudio Silva; Vera Constantino; Marcia Temperini
Chemistry Institute - Universidade de São Paulo, São Paulo, Brazil
View Abstract PDF
Summary
Hybrid films of Polyaniline (PANI) and Hexaniobate nanosheets were prepared by electrostatic layer-by-layer assembly technique (LbL) and characterized by UV-Vis-NIR absorption and resonance Raman (RR) spectroscopies. UV-Vis-NIR spectrum of LbL film presents the absorption tail in NIR region, assigned to delocalized free charge carriers, suggesting that PANI chains are in extended conformation. RR spectrum (632.8 nm excitation radiation) of LbL film shows higher relative intensities of band at 1335 cm-1 (radical-cation segments) to band at 1485 cm-1 (quinoid segments) comparing to as-synthesized solid PANI, indicating that LbL film presents PANI in a higher doping level comparing to solid polymer.

Code: MP26	Time Slot/Poster Number: 065	Session: Molecular Electronics and Polymers
In Situ Electrical And Raman Investigations Of Inkjet-Printed PEDOT:PSS Layers
Beynor Antonio Paez-Sierra1; Franz Padinger2
1QUBITON Laboratories, Linz, Austria; 2NANOIDENT Technologies AG, Linz, Austria
View Abstract PDF
Summary
We report combined Raman spectroscopy and voltages to investigate PEDOT:PSS produced by inkjet printing technology. Applied voltages clearly modify the chemical identity of PEDOT:PSS. The phenomena was assigned to dedoping and evidenced from the red-shift of the C_α=C_β stretching band. In addition, after switching off the applied voltage the structure partially recovers. The applied voltage in addition induces dipole states in the polymer chain. The chemical and physical properties of PEDOT:PSS layers entangled in a more complex architectures i.e. organic light-emitting diodes (OLEDs) or organic field-effect transistors (OFETs), might be irreversibly modified by the driving voltages.

Code: MP26	Time Slot/Poster Number: 066	Session: Molecular Electronics and Polymers
Raman Characterization of Oligoaniline Self- Assembled Microspheres
Daniela Ferreira; Marcia Temperini
University of São Paulo, São Paulo, Brazil
View Abstract PDF
Summary
The structure of oligoaniline obtained by oxidative polymerization of aniline and persulfate at buffer solution pH3 was elucidate by resonance Raman spectroscopy. A relation between morphology and structure was observed through Raman microscopy and SEM technique.

Code: MP26	Time Slot/Poster Number: 068	Session: Molecular Electronics and Polymers
The Nature of the Dimethylsulfoxide/Squaric Acid Interaction by Raman Spectroscopy
Stéfanos Leite Georgopoulos; Luiz Fernando Cappa de Oliveira
Universidade Federal de Juiz de Fora, Juiz De Fora, Brazil
View Abstract PDF
Summary
Raman spectra of solutions of squaric acid in dimethilsulfoxide in several different concentrations were used to calculate the dissociation degrees for squaric acid; these values were compared to water solutions, showing in DMSO the acid behaviour of squaric acid is almost the same. The Raman spectra also allow inferring the interaction between squaric acid and DMSO by means the formation of a molecular complex, besides the dissociation, with the influence of some vibrational modes involved in hydrogen bonds, such as the νCC band at 1000-1200 cm-1.

Code: MP26	Time Slot/Poster Number: 069	Session: Molecular Electronics and Polymers
Engineered Molecular Semiconductors: A Confocal Scanning Raman Spectroscopy (CSRS) Analysis
Beynor Antonio Paez-Sierra1; Viktoriia Kolotovska2
1QUBITON Laboratories, Linz, Austria; 2Technische Universitaet Chemnitz, Chemnitz, Germany
View Abstract PDF
Summary
We present CSRS measurements of magnetically modified vanadyl phthalocyanine (VOPc) layers forming conduction channels in organic field-effect transistors (OFETs). The VOPc films were produced by organic molecular beam deposition in high vacuum. As substrates SiO2/n+-Si with interdigitated Au/Cr electrodes were used. During the growth conditions the substrates were exposed to a magnetic field from a bar magnet positioned either in parallel or perpendicular to the substrate plane, and without. The Raman images present differences between the vibrational distribution of the VOPc layers grown onto Au and onto SiO2 surfaces, and notorious evidence of the effect due to the preparation conditions.

Code: MP26	Time Slot/Poster Number: 070	Session: Molecular Electronics and Polymers
Structural and Electronic Studies of Nonlinear Optical Donor-Acceptor Compounds
Matthew Reish1; Keith Gordon1; Andy Kay2
1University of Otago, Dept of Chemistry, Dunedin, New Zealand; 2Industrial Research Limited, Wellington, NZ
View Abstract PDF
Summary
Compounds with electron-donor and -acceptor moieties connected through a π-chain are good candidates for use in nonlinear optics because of their very high hyperpolarizabilities (β). The hyperpolarizability of these compounds is highly tunable both by design and by their environment. The macroscopic nonlinearty found in working devices relies, amongst other things, on a non-centrosymmetric ordering which can be hampered by the tendency of merocyanine dyes to aggregate in low polarity media. Both the hyperpolarizablilty and aggregation of a merocyanine dye are analyzed.

Code: MP26	Time Slot/Poster Number: 071	Session: Molecular Electronics and Polymers
Interionic interactions in ionic liquids: the role of the C2-position revealed by Raman and supported by IR and NMR spectroscopy
Kristina Noack1; Natalie Paape2; Johannes Kiefer1; Peter Wasserscheid2; Alfred Leipertz1
1Lehrstuhl für Technische Thermodynamik, Erlangen, Germany; 2Lehrstuhl für Chemische Reaktionstechnik, Erlangen, Germany
View Abstract PDF
Summary
The ratio of Coulomb and van der Waals interactions influences the physicochemical properties of room temperature ionic liquids (RTILs). In this work we performed Raman experiments in 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [RMIM][Tf2N]-RTILs. Thereby, we focused on substitution in the C2-position, which is the main interaction site of the cation and anion, and its effects on the RTILs' molecular structures and physicochemical properties. The findings yield new vibrational modes and red shifts of existing modes. Furthermore, those trends are supplemented by ATR IR- and completed by NMR-data showing chemical shift migrations to the downfield.

Code: MP26	Time Slot/Poster Number: 072	Session: Molecular Electronics and Polymers
Density Functional Theoretical Study of Oligomers of Poly(p-phenylene sulfide) (PPS)
Naresh Kumar; Poonam Tandon
University of Lucknow, Lucknow, India
View Abstract PDF
Summary
Poly (p-phenylene sulfide) (PPS) is a synthetic polymer which, due to a variety of reasons has gained considerable scientific and industrial interest. It is a high-temperature-engineering polymer with very high potential. It has unusual thermosetting/ thermoplastics characteristics and exhibits good mechanical properties, thermal stability, chemical resistance, flame resistance, and precision moldability. These properties make it useful in connectors for electrical and optical-fiber cable, chip carriers, print-wiring board substrates and components for electronic encapsultants.

Code: MP26	Time Slot/Poster Number: 073	Session: Molecular Electronics and Polymers
Vibrational Study on Poly(Methylmethacrylate) - A Novel Industrial Polymer
Mohan Sriramulu
HAWASSA UNIVERSITY, Hawassa, ETHIOPIA
View Abstract PDF
Summary
The FTIR spectrum of POLY(METHYLMETHACRYLATE)compounds have been recorded by Bruker IFS 66v spectrometer. The temperature dependence of vibrational spectra of solutions of stereo regular PMMA, and the effect of various solvents on vibrational spectra of PMMA, have been studied. A series of measurements of FTIR spectra of i- and s-PMMA and of the stereo complex in the solid state and in solutions have been made. The temperature dependences were measured in a commercial heated cell. The polymer films were prepared by evaporation from acetonitrile and chloroform solutions on AgCl or KBr pellets.

Code: MP26	Time Slot/Poster Number: 074	Session: Molecular Electronics and Polymers
The Role of Electronic Coupling in Various Porphyrin Arrays Probed by Raman and Single Molecule Fluorescence Spectroscopy
Dongho Kim
Seoul, South Korea
View Abstract PDF
Summary
In the present study, we have chosen two archetypes that are featuring distinctive electronic couplings induced from the difference in the type of linkages; one is butadiyne-bridged porphyrin arrays ZNb and the other is directly linked porphyrin arrays ZN. Single molecule fluorescence spectroscopy including fluorescence intensity and lifetime as well as Raman measurements were performed to comparatively investigate the role of electronic couplings in the excited state dynamics of the two porphyrin arrays. Our results on these spectroscopic observations allow for a better understanding of how the light-signal transmission mechanism changes according to the electronic couplings.

Code: MP26	Time Slot/Poster Number: 075	Session: Molecular Electronics and Polymers
Raman Spectra and Quantum Chemistry Calculations of Fluorene-Dibenzothiophene-S,S-dioxide Oligomers
José L. Zafra1; Irene I. Perepichka2; Igor F. Perepichka3; Martin R. Bryce4; Francisco J. Ramirez1; Juan Casado1; Juan T. López-Navarrete1
1Dep. Química Física, Univ. Málaga, Málaga, Spain; 2Dep. Chimie, Univ. Montréal, Montréal, Canada; 3Centre for Materials Science, U. C. Lancashire, Preston, United Kingdom; 4Dep. Chemistry, Univ. Durham, Durham, United Kingdom
View Abstract PDF
Summary
Fluorene-based polymers (F) are one of the most promising materials for electroluminiscent applications, due to their efficient emission, high physico-chemical stability and easy tuning of the emission wavelength by side-chain modifications or copolymerization. Moreover, the charge-transport can be improved by introducing electron-acceptor moieties into the polymer backbone to form alternating copolymers. Co-polymers and co-oligomers of F with dibenzothiophene-S,S-dioxide (S) have shown high luminescence efficiency, improved electron affinity and excellent performance in OLEDs. This work reports Raman spectroscopy studies some FS co-oligomers as models to investigate the conjugational effect of modulating structural variables such as chain length and donor-acceptor separation.

Code: MP26	Time Slot/Poster Number: 076	Session: Molecular Electronics and Polymers
In Situ Vibronic And Electric Assessments In Organic-Based Electronics
Beynor Antonio Paez-Sierra1, 2; Franz Padinger2
1QUBITON Laboratories, Linz, Austria; 2NANOIDENT Technologies AG, Linz, Austria
View Abstract PDF
Summary
Semiconducting organic polymers are of great interest due to bond conjugation and delocalization of electrons at π orbitals. These interesting properties make organic molecules a well-suited building block for modern plastic electronic applications. In this report, the simultaneous Raman spectroscopy and electrical characterization technique to investigate organic-based devices and molecular structures is addressed. The measured Raman bands of Glass/ITO/PEDOT/P3HT/Al and Glass/ITO/PEDOT/P3HT:PCBM/Al based structures proved to be well sensitive to the applied bias in contrast with the current-voltage measurements, where the reversible region of the device is overestimated.

Code: MP26	Time Slot/Poster Number: 077	Session: Molecular Electronics and Polymers
Vibrational Analysis Of Molecular Electronics: Perylene Derivative-Based Transistors
Beynor Antonio Paez-Sierra1, 2
1QUBITON Laboratories, Linz, Austria; 2NANOIDENT Technologies AG, Linz, Austria
View Abstract PDF
Summary
Organic electronics are devices based on organic molecules with semiconducting or conducting properties. In this report two perylene PTCDA and DiMePTCDI are discussed. The ex-situ confocal scanning Raman spectroscopy analysis was performed under normal room conditions. The PTCDA-based device revealed a very similar Raman intensity on both substrates. In the case of DiMePTCDI OFETs the vibrational signal of the layer deposited onto the Au electrode is about fivefold much higher than from that one growth on the SiO2 substrate. In addition, the anisotropy of the DiMePTCDI layer is higher in comparison with that of the PTCDA OFETs.

Code: MP26	Time Slot/Poster Number: 078	Session: Molecular Electronics and Polymers
Morphology Evolution Of Inkjet Printed Blends For Photovoltaic Applications
Beynor Antonio Paez-Sierra
QUBITON Laboratories, Linz, Austria
View Abstract PDF
Summary
Organic electronic applications such OLEDs, OFETs, photovoltaics, produced by inkjet technology permits to form defined patterns at specific locations on bendable/rigid substrates, and provides fast production of organic-based devices over large area. In this report inkjet printed organic semiconducting layers used as photosensors are investigated by Raman spectroscopy. The organic-semiconducting ink is realized by blending in an appropriate solvent the p-type and n-type polymers P3HT and PCBM, respectively. Then the ink is printed onto glass substrates. Raman analysis proved that drop spacing during printing out of the semiconducting films and their post-annealing dramatically influence their optical and morphological properties.

Code: MP26	Time Slot/Poster Number: 079	Session: Molecular Electronics and Polymers
2D Correlation Raman Spectroscopy of Hyperbranched Polymer
Ashok Z. Samuel; Siva Umapathy; S Ramakrishnan
Indian Institute of Science, Bangalore, India
View Abstract PDF
Summary
The present study investigate the conformational modifications of hyperbranched polymer during melting using 2D Correlation Raman Spectroscopy. Peripheral functionalized (PEG-ylated) hyperbranched polyethers made following transetherification methodology has been shown to reorganize in solution. This feature was further utilized to generate self-assembled nanostructures. In order to examine the nature of molecular reorganization, variable temperature IR and Raman spectroscopic studies have been conducted on hyperbranched polymers with crystallizable (Docosanol) units on the periphery. The variation in the 2D correlation spectrum as a function of incorporation of PEG on to the crystallizable HB polymer will also be discussed.

Code: MP26	Time Slot/Poster Number: 080	Session: Molecular Electronics and Polymers
Semiconducting Inks For Printed Electronics: A Raman Spectroscopy Analysis
Beynor Antonio Paez-Sierra
QUBITON Laboratories, Linz, Austria
View Abstract PDF
Summary
In this letter the life time of semiconducting inks used for inkjet printing technology is reported. The significant changes between the fresh and aged ink correspond to the participation of the solvents and well-evidenced below 1000 cm-1. Interestingly is that the lifetime of the ink in the cartridge is about one hour. After an hour the printed layers present notorious changes of wetting, and morphology. This is because the cartridge is partially sealed and at each time when the layers are printed the nozzles are opened, thus resulting in alteration of the solvents proportions in the cartridge.

Code: MP26	Time Slot/Poster Number: 081	Session: Molecular Electronics and Polymers
Confocal Scanning Raman Spectroscopy (CSRS) Of An Operating Organic Light-Emitting Diode
Beynor Antonio Paez-Sierra1, 2; Henrique Gomez3
1QUBITON Laboratories, Linz, Austria; 2NANOIDENT Technologies AG, Linz, Austria; 3Universidade do Algarve, CEOT, Faro, Portugal
View Abstract PDF
Summary
Some of the long-standing challenges in OLED technology relay on degradation and failure mechanisms. Degradation and subsequent damage of OLEDs is accompanied by formation of dark non-emissive spots. We report ex situ CSRS analysis of the an OLED under operation and in normal room conditions. The non-emissive spots presented higher Raman intensity in comparison with the luminescent ones. The phenomenon is associated with an increase in the PFO π-π* absorption band which becomes favorable to the excitation wavelength, thus the Raman spectrum is enhanced. A relation between the number of molecules that might emitt and vibrational bands was found.

Code: MP26	Time Slot/Poster Number: 082	Session: Molecular Electronics and Polymers
Raman Spectroscopic Investigation of Plasma-Sprayed Zirconia-Based Electrolytes
Andrea Haug1; Claudia Christenn1; Britt-Elfriede Schuster1; Günter Schiller1; Thomas Chassé2; K. Andreas Friedrich1
1Deutsches Zentrum für Luft- und Raumfahrt e.V., Stuttgart, Germany; 2University of Tübingen, Tübingen, Germany
View Abstract PDF
Summary
Solid oxide fuel cells (SOFC) are devices converting directly chemical into electrical energy. The SOFC electrolyte layer typically consisting of yttria-stabilized zirconia (YSZ) was prepared using atmospheric plasma spraying technology. Plasma spraying allows the optimization of the layers’ porosity that affect the fuel cell performance. In order to get further information concerning the thin-film properties of plasma-sprayed zirconia-based electrolytes X-ray diffraction (XRD) as well as scanning electron microscopy (SEM) were applied.