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1

Electronic Properties of Structures Containing Films of Alq₃ and LiBr Deposited on Si(111) Crystal

100%

Sito J., Grodzicki M., Lament K., Wasielewski R., Mazur P., Ciszewski A.

Acta Physica Polonica A

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2017

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vol. 132

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issue 2

357-360

EN

The electronic structures of Alq₃/Si(111) and Alq₃/LiBr/Si(111) interfaces are presented in this report. The studies were carried out in situ in ultrahigh vacuum by ultraviolet photoelectron spectroscopy. Alq₃ and LiBr layers were vapour deposited onto a single crystal of n-type Si(111). The energy level diagrams were prepared for the structures. The formation of the LiBr interfacial layer results in a decrease of the energy barrier at the interface.

2

Functional Π-conjugated polymers based on maleimide for photovoltaic applications

84%

Gironda R., Miozzo L., Tondelier D., Chaigneau M., Ghabboun J., Faroun M., Papagni A., Salamone M. M., Ruffo R., Yassar A.

Organic Photonics and Photovoltaics

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2013

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vol. 1

56-66

EN

A series of new bis-(2-thienyl) maleimide monomers have been synthesized and characterized. The bis-(2- thienyl)maleimide unit has been copolymerized with different aromatic comonomers. Stille coupling polymerizations under various conditions have been utilized. The copolymers were then characterized by size-exclusion chromatography and their optical and electronic properties were investigated by UV-Vis absorption spectroscopy and cyclic voltammetry. All maleimide based copolymers shared similar LUMO energy levels, which are largely determined by the acceptor moiety, and are close to that of PC61BM to be effective for charge dissociation. These low band gap polymers have been tested for photovoltaic applications and have shown moderate photovoltaic performance. Interesting results were obtained by adding the polymer to the P3HT:PC61BM mixture, as a third component. The ternary blend BHJ solar cells showed power conversion efficiencies of 35% exceeding those of the corresponding binary blends.

3

Efficiency enhancement of P3HT:PCBM solar cells containing scattering Zn-Al hydrotalcite nanoparticles in the PEDOT:PSS layer

84%

Bolognesi M., Tessarolo M., Posati T., Nocchetti M., Benfenati V., Seri M., Ruani G., Muccini M.

Organic Photonics and Photovoltaics

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2013

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vol. 1

1-10

EN

In this article we report on a new hybrid (organic-inorganic) composite material based on hydrophilic, electrically inert and semi-transparent hydrotalcite (HT) nanoparticles and a pHneutral formulation of PEDOT:PSS. The application of this composite material as electrically and optically active buffer layer in P3HT:PC61BM bulk heterojunction (BHJ) solar cells is reported. Two different synthetic routes are explored to obtain HTs having discoid shape, with a diameter of around 150- 200 nm and a thickness of ~20 nm, to be easily embedded in ~50 nm thick PEDOT:PSS films. The good affinity between HTs and the sulfonate groups of the PEDOT:PSS allows to obtain homogeneous HTs/PEDOT:PSS films, for HT concentrations of 0.25% and 0.50% by weight (vs. PEDOT:PSS). At these particle loads the electrical and morphological features of doped and undoped PEDOT:PSS films are nearly identical, while providing a significant effect on the visible light scattering properties of the composite films. We demonstrate ~12% improvement in power conversion efficiency (PCE) for P3HT:PC61BM solar cells incorporating HTs in the PEDOT: PSS layer, which mainly originates from increased shortcircuit current densities (JSC).

4

Network Properties of Ureasil-Based Polymer Matrixes for Construction of Amperometric Biosensors as Probed by PALS and Swelling Experiments

84%

Kavetskyy T., Šauša O., Čechová K., Švajdlenková H., Mat'ko I., Petkova T., Boev V., Ilcheva V., Smutok O., Kukhazh Y., Gonchar M.

Acta Physica Polonica A

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2017

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vol. 132

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issue 5

1515-1518

EN

Network properties of ureasil-based polymer matrixes suitable for construction of amperometric biosensors were probed by positron annihilation lifetime spectroscopy and swelling experiments. Temperature dependences of the ortho-positronium (o-Ps) lifetimes and their relative intensities were measured in a temperature range of 15-350 K. Glass transition temperatures and expansion coefficients of microscopical free-volume for the investigated polymers were determined. Differences in network behavior for the aged samples and the effect of chalcogenide (As₂S₃) particles on the free volume of ureasil network were observed. Swelling experiments using ethyl alcohol showed that the structure of the aged sample network had less swelling ability for the pure ureasil as well as composite. This suggests that the one of factors influencing swelling is the change of the basic ureasil network due to ageing. It is supposed that the network properties obtained by positron annihilation lifetime spectroscopy and swelling experiments could be very helpful to understand better the bio-functionality of the constructed biosensor based on the ureasil-chalcogenide glass composite.

Refine search results

Electronic Properties of Structures Containing Films of Alq₃ and LiBr Deposited on Si(111) Crystal

Functional Π-conjugated polymers based on maleimide for photovoltaic applications

Efficiency enhancement of P3HT:PCBM solar cells containing scattering Zn-Al hydrotalcite nanoparticles in the PEDOT:PSS layer

Network Properties of Ureasil-Based Polymer Matrixes for Construction of Amperometric Biosensors as Probed by PALS and Swelling Experiments