41. A nanomesh scaffold for supramolecular nanowire optoelectronic devicesLei Zhang, Egon Pavlica, Gvido Bratina, 2016, original scientific article Abstract: Supramolecular organic nanowires are ideal nanostructures for optoelectronics because they exhibit both efficient exciton generation as a result of their high absorption coefficient and remarkable light sensitivity due to the low number of grain boundaries and high surface-to-volume ratio. To harvest photocurrent directly from supramolecular nanowires it is necessary to wire them up with nanoelectrodes that possess different work functions. However, devising strategies that can connect multiple nanowires at the same time has been challenging. Here, we report a general approach to simultaneously integrate hundreds of supramolecular nanowires of N,N′-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) in a hexagonal nanomesh scaffold with asymmetric nanoelectrodes. Optimized PTCDI-C8 nanowire photovoltaic devices exhibit a signal-to-noise ratio approaching 107, a photoresponse time as fast as 10 ns and an external quantum efficiency >55%. This nanomesh scaffold can also be used to investigate the fundamental mechanism of photoelectrical conversion in other low-dimensional semiconducting nanostructures. Keywords: fotodetektor, organski polprevodnik, fotoprevodnost, organski kristal, elektronske komponente, nanožice Published in RUNG: 05.10.2016; Views: 5309; Downloads: 0 This document has many files! More... |
42. Pozabljeni zdravnik : Vloga dr. Karla Pečnika pri vprašanju slovenske gospodarske samostojnosti in vključevanja v mednarodno trgovino.Rok Bratina, 2016, undergraduate thesis Abstract: Diplomska naloga obravnava življenje in delo dr. Karla Pečnika, vsestransko izobraženega slovenskega izseljenca, ki je velik del svojega življenja preživel kot zdravnik jetičnih bolezni v Egiptu. Pričujoča naloga se osredotoča na Koroščevo brošuro Slovenci in mednarodni promet, ki jo je Pečnik napisal na podlagi večletnega preučevanja gospodarskega dogajanja v Egiptu. Ker je bil zelo dobro obveščen tudi o stanju v domovini, je s pomočjo goriškega politika Andreja Gabrščka leta 1898 izdal omenjeno brošuro v kateri je želel spodbuditi Slovence k bolj samostojnemu gospodarskemu delovanju, neodvisnemu od ostalih dežel v Habsburški monarhiji. Kot je zapisal Pečnik, je svetovna trgovina odpravila vse omejitve, ki bi lahko ovirale slovenske dežele na poti do gospodarske samostojnosti.
Namen in cilj pričujoče diplomske naloge je bil predstaviti življenje in delo Karla Pečnika, ga ponovno obuditi v slovenski gospodarski zgodovini in ga v prihodnje predstavljati kot enega tistih posameznikov, ki so imeli eno pomembnejših vlog pri nadaljnjem razvoju slovenskega gospodarstva. Dokaz za to je danes moč najti v njegovi brošuri Slovenci in mednarodni promet. Keywords: Habsburška monarhija, gospodarstvo, liberalizem, mednarodna trgovina, slovenske dežele, Egipt, Karol Pečnik. Published in RUNG: 04.10.2016; Views: 5497; Downloads: 243 Full text (933,38 KB) |
43. Flexible non-volatile optical memory thin-filmtransistor device with over 256 distinct levelsbased on an organic bicomponent blendGvido Bratina, Egon Pavlica, 2016, original scientific article Abstract: Flexible non-volatile optical memory thin-filmtransistor device with over 256 distinct levelsbased on an organic bicomponent blendTim Leydecker1, Martin Herder2, Egon Pavlica3,GvidoBratina3,StefanHecht2*, Emanuele Orgiu1*and Paolo Samorì1*Organic nanomaterials are attracting a great deal of interest for use in flexible electronic applications such as logiccircuits, displays and solar cells. These technologies have already demonstrated good performances, but flexible organicmemories are yet to deliver on all their promise in terms of volatility, operational voltage, write/erase speed, as well asthe number of distinct attainable levels. Here, we report a multilevel non-volatile flexible optical memory thin-filmtransistor based on a blend of a reference polymer semiconductor, namely poly(3-hexylthiophene), and a photochromicdiarylethene, switched with ultraviolet and green light irradiation. A three-terminal device featuring over 256 (8 bitstorage) distinct current levels was fabricated, the memory states of which could be switched with 3 ns laser pulses.We also report robustness over 70 write–erase cycles and non-volatility exceeding 500 days. The device was implementedon a flexible polyethylene terephthalate substrate, validating the concept for integration into wearable electronics andsmart nanodevices. Keywords: organic semiconductors
time of flight Published in RUNG: 22.06.2016; Views: 5498; Downloads: 0 This document has many files! More... |
44. Effect of water layer at the SiO[sub]2/graphene interface on pentacene morphologyEgon Pavlica, Gvido Bratina, Manisha Chhikara, Radoš Gajić, Aleksandar Matković, 2014, original scientific article Keywords: grafen, mikroskopija, atomska sila, organski polprevodniki, tanki sloji Published in RUNG: 16.06.2016; Views: 5165; Downloads: 207 Link to full text |
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46. Graphene-induced enhancement of n-type mobility in perylenediimide thin filmsGvido Bratina, Egon Pavlica, Srinivasa Rao Pathipati, Andrea Schlierf, Mirella El Gemayel, Paolo Samorì, Vincenzo PALERMO, 2014, original scientific article Keywords: grafen, transportne lastnosti, organski tankoslojni tranzistorji, tok fotovzbujenih nosilcev naboja Published in RUNG: 16.06.2016; Views: 4791; Downloads: 134 Link to full text |
47. Influence of a gold substrate on the optical properties of grapheneGvido Bratina, Manisha Chhikara, Aleksandar Matković, Radoš Gajić, Marijana Milićević, Uroš Ralević, Borislav Vasić, Djordje Jovanović, Milivoj R. Belić, 2015, original scientific article Keywords: grafen, mikroskopija na atomsko silo, spektroskopska elipsometrija Published in RUNG: 16.06.2016; Views: 5004; Downloads: 225 Link to full text |
48. Electrical conductivity in 3,4,9,10-perylenetetracarboxylic dianhidride (PTCDA)Gvido Bratina, Robert Hudej, Marko Zavrtanik, John Nimly Brownell, 2001, original scientific article Abstract: The transient photoresponse in 3,4,9,10-perylenetetracarboxylic dianhydride was examined in metal/organic semiconductor/metal heterostructures. Electron-hole pairs are generated within the structure for fields higher than 5 X 10[sup]4 V/cm as a consequence of the exciton dissociation. The mobility of the electrons perpendicular to the molecular layers increases with the applied electric field and saturates for fields higher than 5 X 10[sup]4 V/cm. Keywords: organic semiconductor, thin films, transient photoconductivity Published in RUNG: 10.07.2015; Views: 6523; Downloads: 40 Link to full text |
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50. Transport električnega naboja v organskih polprevodnikih, simulacija po metodi Monte CarloRobert Hudej, Gvido Bratina, Egon Pavlica, 2003, original scientific article Abstract: The electric-charge transport in organic semiconductors is essentially different to the transport in ordered inorganic crystals. The reason is in thelocalization of the energy states, which act as charge-carrier transport channels between molecules. Consequently, the determination of the basic transport parameters in organic materials is inherently more involved than in their inorganic counterparts. The analytical methods that are used to describe charge transport in inorganic materials are unsuitable, since they are based on the extended electronic energy structure. We report here on the simulation of charge transport in organic semiconductor thin films. The simulation is based on the Monte Carlo method and describes the charge-carrier transport within the framework of carrier hopping between the sites. We employed a Gaussian energy distribution of the hopping sites with disorder elements. The degree of disorder is characterized by the width of the Gaussian distribution and is measured in eV units. The results of the transport simulation in 3,4,9,10-perylenedianhydride tetracarboxylic acid (PTCDA) show that the photogenerated charge-carrier current depends on the film thickness, temperature and disorder degree. The simulated photocurrents have the same amplitude in thick films as in the thin films, but the overall shape of the I(t) curve is more dispersive in thin films. The charge-carrier mobility decreases with the increasing degree of disorder at a given temperature. The simulation of the photogenerated positive charge carriers current matches with the time-of-flight experiment in a glass/ITO/PTCDA(600 nm)/In heterostructure at room temperature and an applied bias voltage of 8 V. Keywords: neurejeni kristali, metoda Monte Carlo, organski polprevodniki, transport naboja, PTCDA, tranzientne meritve Published in RUNG: 10.07.2015; Views: 5824; Downloads: 23 Link to full text |