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1. Influence of Sidechain Elongation on Photovoltaic Response of Sidechain-Based Statistical Anthracene-Containing Copolymer

Author

Boudiba Sameh, Adam Getachew, Ulbricht Christoph, Enengl Sandra, Enengl Christina, Boudiba Louiza, and Ayuk Mbi Egbe Daniel

Subjects
Environmental sciences, GE1-350
Abstract

A new sidechain-based statistical anthracene-containing poly(arylene-ethynylene)-alt-poly(p-phenylene-vinylene) (P2) bearing 2-ethylhexyloxy and decyloxy side chains was synthesized to study the effect of elongating the sidechain length from octyloxy (as in P1) to decyloxy (as in P2) on the photovoltaic performance. The polymer was prepared using the Horner-Wadsworth-Emmons olefination reaction of two dialdehydes with two bisphosphonate esters. NMR and FTIR spectroscopy characterization were employed to prove the formation of the desired polymeric structure. The photophysical and electrochemical properties showed a broad spectral range of absorption in the visible region and reversible redox activity, respectively. Thermogravimetric analysis (TGA) indicated good thermal stability. Non-optimized bulk-heterojunction solar cells achieved power conversion efficiency (PCE) of 2.4 % for P2. The reduced performance of P2 compared to P1 based solar cells (PCE 3.8%) might originate from inferior nanomorphology of the active layer blend and/or the “dilution” of the photoactive conjugated backbone upon elongation of solubilising sidechains.

Published
2022
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5. Synthesis and Photophysical and Electroluminescent Properties of Poly(1,4-phenylene–ethynylene)-alt-poly(1,4-phenylene–vinylene)s with Various Dissymmetric Substitution of Alkoxy Side Chains

Author

Bouguerra, Nassima, Růžička, Aleš, Ulbricht, Christoph, Enengl, Christina, Enengl, Sandra, Pokorná, Veronika, Výprachtický, Drahomír, Tordin, Elisa, Aitout, Razika, Cimrová, Věra, and Egbe, Daniel Ayuk Mbi

Subjects
Article
Abstract

The synthesis and characterization of a set of conjugated polymers, poly(1,4-phenylene–ethynylene)-alt-poly(1,4-phenylene–vinylene)s (PPE–PPVs), with a dissymmetrical configuration (partial or total) of alkoxy side chains is reported. Five new polymers bearing octyloxy and/or octadecyloxy side chains at the phenylene–ethynylene and phenylene–vinylene segments, respectively, were obtained. Two symmetrical substituted polymers were used for comparison. Polymers with weight-average molecular weight, Mw, up to 430 000 g/mol and degree of polymerization between 17 and 322 were obtained by a Horner–Wadsworth–Emmons olefination polycondensation reaction of the respective luminophoric dialdehydes and bisphosphonates. As expected, identical conjugated backbones in all polymers results in very similar photophysical response in dilute solution, with high fluorescence quantum yields between 50% and 80%. In contrast, the thin film properties are dependent on the combinatorial effects of side chain configuration, molecular weight, and film thickness parameters, which are the basis of the resulting comparison and discussion.

Published
2016

8. Characterization of Silicon Surface Passivation by Photoluminescence/Raman Spectroscopy

Author

Đerek, Vedran, Scharber, Markus C., Enengl Christina, Głowacki, Eric D., Kosović, Marin, Sariciftci, Niyazi Serdar, Ivanda, Mile, Popp, Jürgen, and Deckert, Volker

Subjects
photoluminescence, Raman, Silicon, Surface passivation
Abstract

Maximization of the power conversion efficiency (PCE) in nanostructured silicon/ PEDOT:PSS hybrid solar cells is an active area of photovoltaic research, due to the reduced thermal budget in production of such devices in comparison to conventional silicon solar cells [1]. Surface passivation of silicon at silicon/organic interface was found to be essential for high efficiency of silicon-based photovoltaics. Surface defects and dangling bonds significantly increase the recombination rate of minority carriers, may pin the Fermi level and cause undesirable band bending at silicon interfaces [2]. Passivation methods for planar silicon surfaces that are currently available [3] are not always compatible with the nanostructured and hybrid organic/inorganic devices, for which appropriate passivation should be developed. Measuring the state of surface passivation is essential in this process. We present a method for the characterization of surface passivation of silicon by simultaneous band gap photoluminescence and Raman spectroscopy.

Published
2014

10. Polymers with alternating anthracene and phenylene building blocks linked by ethynylene and/or vinylene units: Studying structure‐properties‐relationships

Author

Boudiba, Sameh, primary, Růžička, Aleš, additional, Ulbricht, Christoph, additional, Enengl, Sandra, additional, Enengl, Christina, additional, Gasiorowski, Jacek, additional, Yumusak, Cigdem, additional, Pokorná, Veronika, additional, Výprachtický, Drahomír, additional, Hingerl, Kurt, additional, Zahn, Dietrich R. T., additional, Tinti, Francesca, additional, Camaioni, Nadia, additional, Bouguessa, Sabrina, additional, Gouasmia, Abdelkrim, additional, Cimrová, Věra, additional, and Ayuk Mbi Egbe, Daniel, additional

Published
2016
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13. The Role of Heteroatoms Leading to Hydrogen Bonds in View of Extended Chemical Stability of Organic Semiconductors

Author

Enengl, Christina, primary, Enengl, Sandra, additional, Havlicek, Marek, additional, Stadler, Philipp, additional, Glowacki, Eric D., additional, Scharber, Markus C., additional, White, Matthew, additional, Hingerl, Kurt, additional, Ehrenfreund, Eitan, additional, Neugebauer, Helmut, additional, and Sariciftci, Niyazi Serdar, additional

Published
2015
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15. Iodide-Capped PbS Quantum Dots: Full Optical Characterization of a Versatile Absorber

Author

Stadler, Philipp, primary, Mohamed, Shaimaa A., additional, Gasiorowski, Jacek, additional, Sytnyk, Mykhailo, additional, Yakunin, Sergii, additional, Scharber, Markus C., additional, Enengl, Christina, additional, Enengl, Sandra, additional, Egbe, Daniel A. M., additional, El-Mansy, Mabrouk K., additional, Obayya, Salah S. A., additional, Sariciftci, N. Serdar, additional, Hingerl, Kurt, additional, and Heiss, Wolfgang, additional

Published
2015
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17. Polymers with alternating anthracene and phenylene building blocks linked by ethynylene and/or vinylene units: Studying structure-properties-relationships.

Author

Boudiba, Sameh, Růžička, Aleš, Ulbricht, Christoph, Enengl, Sandra, Enengl, Christina, Gasiorowski, Jacek, Yumusak, Cigdem, Pokorná, Veronika, Výprachtický, Drahomír, Hingerl, Kurt, Zahn, Dietrich R. T., Tinti, Francesca, Camaioni, Nadia, Bouguessa, Sabrina, Gouasmia, Abdelkrim, Cimrová, Věra, and Ayuk Mbi Egbe, Daniel

Subjects
ANTHRACENE, PHENYLENE compounds, CONJUGATED polymers, ELLIPSOMETRY, ELECTROCHEMISTRY
Abstract

ABSTRACT Four conjugated polymers ( P1- P4) consisting of alternating anthracene-9,10-diyl and 1,4-phenylene building blocks connected via ethynylene as well as vinylene ( P1 and P2), ethynylene-only ( P3), and vinylene-only ( P4) moieties, respectively, were synthesized and studied. The phenylene units in all four polymers bear 2-ethylhexyloxy side-chains to promote good solubility. The three polymers with vinylene units ( P1, P2, and P4) were prepared using the Horner-Wadsworth-Emmons reaction. For the synthesis of the arylene-ethynylene polymer P3, the palladium-catalyzed Sonogashira cross-coupling reaction was used. The polymers were characterized by NMR, Fourier transform infrared spectroscopy, and Raman spectroscopy. Photophysical, absorption and photoluminescence, and electrochemical properties were studied. Spectroscopic ellipsometry measurements were performed to gain more insight on the optical properties. In addition, the transport properties were investigated using admittance spectroscopy. The bulk hole mobility and its dependence on the electric field were evaluated for P1 and P2. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 129-143 [ABSTRACT FROM AUTHOR]

Published
2017
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