151. High charge carrier mobility in thin films of quasi-two-dimensional polyacetylenes with sulphuric inter-chain linkersNadiia Pastukhova, Gvido Bratina, Egon Pavlica, 2023, published scientific conference contribution abstract Abstract: Quasi-two-dimensional conjugated polymers (q2DCP) have been described and recognised as crystalline, one- or two-layer polymer nanosheets prepared by arranging linear conjugated polymer chains in a 2D plane via non-covalent interchain interactions.[1,2] The extension of polymer dimensionality to two dimensions improves the alignment of individual polymer layers and overcomes the limitations associated with charge carrier hopping between polymer chains in one-dimensional and crosslinked polymers [3] Compared to other two-dimensional materials such as graphene or transition metal dichalcogenides, q2DCPs offer a high degree of flexibility in chemical design and are compatible with liquid-based processing methods. Various q2DCPs have been synthesized by surface active monolayer-assisted interfacial synthesis (SMAIS) [5]
The photoreaction of these materials is of particular interest due to their tunable properties such as band gap and associated wavelength-dependent photoexcitation, which enables a wide range of applications in optoelectronic devices. Using time-of-flight photoconductivity measurements (TOF-PC) [4], we investigate the charge transport properties of 2D polyacetylene prepared by the SMAIS method. A typical TOFP measurement of q2D polyacetylene is shown in Figure 1, using a focused nanosecond pulse laser at 325 nm and an electrode spacing of 250 µm. From the polarity of the bias voltage and the duration of the photocurrent, we can determine the polarity, velocity, and mobility of the photo-excited carriers as a function of the applied bias voltage and excitation wavelength. and observed electron mobility of 250 cm2/Vs, which is in the range of the most advanced organic single-crystal small-molecule semiconductors and almost an order of magnitude higher than linear polymeric semiconductors. We investigated the optical absorption and transmission on a lateral scale using scanning near-field optical microscopy (SNOM).
Keywords: 2D polymers, organic semiconductors, q2DPA, SNOM, time-of-flight photoconductivity
Published in RUNG: 25.03.2024; Views: 482; Downloads: 1
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156. Polygroup objects in regular categoriesAlessandro Linzi, 2024, original scientific article Abstract: We express the fundamental properties of commutative polygroups (also known as canonical hypergroups) in category-theoretic terms, over the category $ \mathbf{Set} $ formed by sets and functions. For this, we employ regularity as well as the monoidal structure induced on the category $ {\mathbf{Rel}} $ of sets and relations by cartesian products. We highlight how our approach can be generalised to any regular category. In addition, we consider the theory of partial multirings and find fully faithful functors between certain slice or coslice categories of the category of partial multirings and other categories formed by well-known mathematical structures and their morphisms.
Keywords: polygroup, canonical hypergroup, multiring, Krasner hyperring, regular category, relation
Published in RUNG: 25.03.2024; Views: 466; Downloads: 3
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158. Organic and flexible : lecture at Ženske v znanosti in za znanost, Ljubljana, 12. 2. 2024Nadiia Pastukhova, 2024, unpublished conference contribution Abstract: The development of organic semiconductors (OS) opens a new perspective and possibilities for novel device architectures including flexible and wearable electronics. One of the key parameters is the charge carriers' mobility. In OSs, it is affected by many factors, including molecular stacking, chemical impurities, temperature, pressure, electric field, and charge carrier density. These factors can affect the structural or energetic disorder. To overcome limitations, new polymers that extend the π-conjugation to two dimensions were developed. The two-dimensional network structure provides a high degree of structural stability and tunability of properties, while the organic molecules can be engineered to exhibit specific chemical and physical properties such as large surface area, pore size, and electronic properties. I will present our recent research, where quasi-2D polyacetylene (q2DPA) demonstrates high electron mobility along the direction of the layer, measured by the lateral time-of-flight photoconductivity (TOF) method.
Keywords: 2D polymers, time-of-flight photoconductivity, TOF, organic semiconductors
Published in RUNG: 22.03.2024; Views: 547; Downloads: 2
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160. Pregled pridelave grozdja in vina žlahtne vinske trte (Vitis vinifera l.) 'pinela' in 'zelen' v Vipavski dolini : diplomsko deloVeronika Kos, 2024, undergraduate thesis Abstract: V tej diplomski nalogi smo s pomočjo anketiranja pridelovalcev pregledali, na kakšen način se prideluje grozdje in vino pri sortah Vitis Vinifera L. 'Zelen' in 'Pinela' v zgornji Vipavski dolini. Pomembno je, da razumemo, da ti dve sorti rasteta na flišni podlagi in pod submediteranskim podnebjem. Ampelografski opis nam razloži, kako ti dve sorti ločimo od ostalih. V nadaljevanju smo s pomočjo anketiranja pridelovalcev teh dveh sort dobili vpogled v način pridelave grozdja, tipe rezi, uporabo ukrepa razlistanja in ugotovili, da je večina vinogradov obrnjenih na vzhod ali zahod. V povprečju dosega mošt/grozdje sorte 'Zelen' višji pH kot sorta 'Pinela', kar tudi vzporedno pojasni, da ima 'Zelen' nižje kisline. Količina pridelanega grozdja se vsako leto povečuje, v grafu lahko vidimo enakomerno rast pri sorti 'Zelen', nekoliko manj enakomerno pa pri sorti 'Pinela', kar je posledica zunanjih dejavnikov. Iz ankete je razvidno, da se tako pri maceraciji kot tudi pri skladiščenju največkrat uporabljajo posode iz nerjavečega jekla, nekateri pa uporabljajo tudi lesene sode.
Keywords: diplomske naloge, pinela, zelen, Vipavska dolina, pridelava, vino, grozdje
Published in RUNG: 21.03.2024; Views: 563; Downloads: 15
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