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An Artist Abroad
Valerija Zabret, 2016, master's thesis

Abstract: The motivation for this thesis was author’s experience as a traveling artists and questioning how experiences abroad influenced her artistic evolution. Nowadays, in the years of globalization and cross-border collaborations, it has become very common for artists to make international connections in order to seek inspiration, funds, connections, exhibition spaces, platforms on which to show their work, studios, workshops, and to establish an international career. The idea of this thesis is to explore the phenomena of traveling artists through literature and analysis of the author’s personal experience and development as an artist in order to identify whether travel is a good practice that should be advised for emerging (or established) artists in order to evolve in their careers. This thesis, “The Influence of a Change in Surroundings on Artistic Creativity,” questions how traveling influences artists and their creativity. It offers a historically overview of the subject and presents contemporary ways and opportunities for artists to travel and work in international environments. In the second part of this thesis, the author presents poetical videos, the “An Artist Abroad – Video Poetry Series,” which were made during the research and through which the author expresses her feelings and observation of her new surroundings. Very personal and poetic work shows the progress and development in the author’s artistic practice, and it shows how new surroundings influenced her creative and production processes.
Found in: ključnih besedah
Summary of found: ...artist, artist abroad, artist residency, traveling artist, mobility, surroundings, change, creativity, influence, production, culture, global,...
Keywords: art, artist, artist abroad, artist residency, traveling artist, mobility, surroundings, change, creativity, influence, production, culture, global, contemporary art, video, poetry, series
Published: 25.02.2016; Views: 4361; Downloads: 107
.pdf Fulltext (7,21 MB)

The Transformative Impact of Blended Mobility Courses
Daniela Brasl, Klemen Širok, Peter Purg, 2016, original scientific article

Found in: ključnih besedah
Keywords: site-specific, methodology, academic mobility, new media, blended, ADRIART
Published: 06.07.2016; Views: 3072; Downloads: 0
.pdf Fulltext (99,11 KB)

The role of local potential minima on charge transport in thin organic semiconductor layers
Egon Pavlica, Raveendra Babu Penumala, Bratina Gvido, 2016, original scientific article

Abstract: We have performed a systematic study of dependence of time-resolved photocurrent on the point of charge excitation within the organic semiconductor channel formed by two coplanar metal electrodes. The results confirm that spatial variation of electric field between the electrodes crucially determines transport of photogenerated charge carriers through the organic layer. Time-of-flight measurements of photocurrent demonstrate that the transit time of photogenerated charge carrier packets drifting between the two electrodes decreases with increasing travelling distance. Such counterintuitive result cannot be reconciled with the spatial distribution of electric field between coplanar electrodes, alone. It is also in contrast to expected role of space-charge screening of external electric field. Supported by Monte Carlo simulations of hopping transport in disordered organic semiconductor layer, we submit that the space-charge screens the external electric field and captures slower charge carriers from the photogenerated charge carrier packet. The remaining faster carriers, exhibit velocity distribution with significantly higher mean value and shorter transit time.
Found in: ključnih besedah
Summary of found: ...Charge transport, Organic semiconductors, Time of flight, Mobility, Traps...
Keywords: Charge transport, Organic semiconductors, Time of flight, Mobility, Traps
Published: 23.12.2016; Views: 3518; Downloads: 0
.pdf Fulltext (950,46 KB)

Best of interviews: Prof. Peter Purg
Peter Purg, 2016, interview

Abstract: Semi-structured interviews with grantees and successful CEEPUS network coordinators have done via skype or telephone. The interview partners have been selected by the National CEEPUS Offices (NCOs) and the Secretary General of CEEPUS. The “best of” of the interviews are presented in the document at hand. The provided material can be used as basis for promotion (e.g. for a brochure or for the CEEPUS web-page) to highlight successful CEEPUS cases. Furthermore, based on the analyses, further recommendations are given on how to reach a better visibility of CEEPUS outcomes and impact.
Found in: ključnih besedah
Keywords: interview, CEEPUS, academic, mobility
Published: 10.04.2017; Views: 2715; Downloads: 0
.pdf Fulltext (618,28 KB)

Nadiia Pastukhova, 2018, doctoral dissertation

Abstract: In this work, we experimentally studied the influence of photoexcitation energy influence on the charge transport in organic semiconductors. Organic semiconductors were small molecules like corannulene, perylene and pentacene derivatives, polymers such as polythiophene and benzothiophene derivatives, and graphene, along with combinations of these materials in heterojunctions or composites. The first part of this study is focused on the photoexcitation energy influence on the transient photoconductivity of non-crystalline curved π-conjugated corannulene layers. The enhanced photoconductivity, in the energy range where optical absorption is absent, is deduced from theoretical predictions of corannulene gas-phase excited state spectra. Theoretical analysis reveals a consistent contribution involving transitions to Super Atomic Molecular Orbitals (SAMOs), a unique set of diffuse orbitals typical of curved π-conjugated molecules. More, the photoconductivity of the curved corannulene was compared to the π-conjugated planar N,N′-1H,1H- perfluorobutyldicyanoperylene-carboxydi-imide (PDIF-CN2), where the photoexcitation energy dependence of photocurrent closely follows the optical absorption spectrum. We next characterized charge transport in poly(3-hexylthiophene) (P3HT) layers deposited from solution. Our results indicate that time-of-flight (TOF) mobility depends on the photoexcitation energy. It is 0.4× 10 −3 cm 2 /Vs at 2.3 eV (530 nm) and doubles at 4.8 eV (260 nm). TOF mobility was compared to field-effect (FET) mobility of P3HT field-effect transistors (OFETs). The FET mobility was similar to the 2.3 eV excitation TOF mobility. In order to improve charge mobility, graphene nanoparticles were blended within a P3HT solution before the deposition. We found that the mobility significantly improves upon the addition of graphene nanoparticles of a weight ratio as low as 0.2 %. FET mobility increases with graphene concentration up to a value of 2.3× 10 −2 cm 2 /Vs at 3.2 %. The results demonstrate that phase segregation starts to influence charge transport at graphene concentration of 0.8 % and above. Hence, the graphene cannot form a bridged conduction channel between electrodes, which would cancel the semiconducting effect of the polymer composite. An alternative approach to enhance mobility is to optimize the molecular ordering of organic semiconductors. For that purpose, we studied an innovative nanomesh device. Free-standing nanomesh devices were used to form nanojunctions of N,N′- iiDioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) nanowires and crystalline bis(triisopropylsilylethinyl)pentacene (TIPS-PEN). We characterized the photocurrent response time of this novel nanomesh scaffold device. The photoresponse time depends on the photon energy. It is between 4.5 − 5.6 ns at 500 nm excitation wavelength and between 6.7 − 7.7 ns at 700 nm excitation wavelength. In addition, we found that thermal annealing reduces charge carrier trapping in crystalline nanowires. This confirms that the structural defects are crucial to obtaining high photon-to-charge conversion efficiency and subsequent transport from pn junction in heterostructured materials. Structural defects also influence the power conversion efficiency of organic heterostructured photovoltaics (OPVs). Anticipating that polymers with different backbone lengths produce different level of structural defects, we examined charge transport dependence on the molecular weight of poly[4,8-bis(5-(2- ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2- ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl] (PTB7-Th) from 50 kDa to 300 kDa. We found p-type hopping transport in PTB7-Th, characterized by 0.1 – 3× 10 −2 cm 2 /Vs mobility, which increases with temperature and electric field. The polymer molecular weight exhibits a non-trivial influence on charge transport. FET mobility in the saturation regime increases with molecular weight. A similar trend is observed in TOF mobility and FET mobility in the linear regime, except for the 100kDa polymer, which manifests in the highest mobility due to reduced charge trapping. The lowest trapping at the dielectric interface of OFET is observed at 200 kDa. In addition, the 200 kDa polymer exhibits the lowest activation energy of the charge transport. Although the 100 kDa polymer indicates the highest mobility, OPVs using the 200 kDa polymer exhibit the best performance in terms of power conversion efficiency.
Found in: ključnih besedah
Summary of found: ...solution. Our results indicate that time-of-flight (TOF) mobility depends on the photoexcitation energy. It is 0.4×...
Keywords: organic semiconductors, optical absorption spectroscopy, time-of-flight photoconductivity, transient photocurrent spectroscopy, organic thin film transistors, atomic force microscopy, superatomic molecular orbitals, pn heterojunction, organic nanowires, graphene, composites, charge mobility, charge trapping, temperature dependence, photodetector, photovoltaic, solar cell, organic electronics
Published: 08.10.2018; Views: 3160; Downloads: 110
.pdf Fulltext (4,56 MB)

Reshaping metropolitan transportation cultures. A comparative study of bicycle friendly cities in Europe and the case of the Metropolitan City of Milano
Ario De Marco, 2019, doctoral dissertation

Found in: ključnih besedah
Summary of found: ...urban mobility, bicycle, urban landscape, active transport, multimodality...
Keywords: urban mobility, bicycle, urban landscape, active transport, multimodality
Published: 29.08.2019; Views: 1353; Downloads: 72
.pdf Fulltext (1,85 MB)

Elucidation of Donor:Acceptor Phase Separation in Nonfullerene Organic Solar Cells and Its Implications on Device Performance and Charge Carrier Mobility
Sebastian F. Hoefler, Georg Haberfehlner, Thomas Rath, Andreas Keilbach, Mathias Hobisch, Alexander Dixon, Egon Pavlica, Gvido Bratina, Gerald Kothleitner, Ferdinand Hofer, Gregor Trimmel, 2019, original scientific article

Abstract: In bulk-heterojunction solar cells, the device performance strongly depends on the donor and acceptor properties, the phase separation in the absorber layer, and the formation of a bicontinuous network. While this phase separation is well explored for polymer:fullerene solar cells, only little is known for polymer:nonfullerene acceptor solar cells. The main hurdle in this regard is often the chemical similarity of the conjugated polymer donor and the organic nonfullerene acceptor (NFA), which makes the analysis of the phase separation via atomic force microscopic (AFM) phase images or conventional transmission electron microscopy difficult. In this work, we use the donor polymer PTB7-Th and the small molecule acceptor O-IDTBR as the model system and visualized the phase separation in PTB7-Th:O-IDTBR bulk-heterojunctions with different donor:acceptor ratios via scanning transmission electron microscopy (STEM) high-angle annular dark-field (HAADF) images and electron energy loss spectroscopy (EELS) based elemental mapping, which resulted in a good contrast between the donor and the acceptor despite very low differences in the chemical composition. AFM as well as grazing-incidence wide-angle X-ray scattering (GIWAXS) investigations support the electron microscopic data. Furthermore, we elucidate the implications of the phase separation on the device performance as well as charge carrier mobilities in the bulk-heterojunction layers, and a high performance of the solar cells was found over a relatively broad range of polymer domain sizes. This can be related to the larger domain sizes of the acceptor phase with higher amounts of O-IDTBR in the blend, while the polymer donor phase still forms continuous pathways to the electrode, which keeps the hole mobility at a relatively constant level.
Found in: ključnih besedah
Keywords: nanomorphology bulk-heterojunction scanning transmission electron microscopy organic photovoltaics charge carrier mobility
Published: 15.01.2020; Views: 1274; Downloads: 46
.pdf Fulltext (6,22 MB)

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