1. Conjugated polymer mesocrystals with structural and optoelectronic coherence and anisotropy in three dimensionsLiyang Yu, Egon Pavlica, Ruipeng Li, Yufei Zhong, Carlos Silva, Gvido Bratina, Christian Műller, Aram Amassian, Natalie Stingelin, 2022, izvirni znanstveni članek Ključne besede: organic semiconductor, time-of-flight, charge carrier mobility, solid processing, large crystal Objavljeno v RUNG: 28.02.2023; Ogledov: 1845; Prenosov: 83 Povezava na celotno besedilo Gradivo ima več datotek! Več... |
2. Van der Waals heterostructuresVadym Tkachuk, doktorska disertacija Ključne besede: Graphene, hexagonal boron nitride, PDI8-CN2, organic semiconductor, heterostructure, charge transport, electronic properties, 2D crystal, 2D crystal transfer, tunneling. Objavljeno v RUNG: 24.10.2022; Ogledov: 2438; Prenosov: 91 Celotno besedilo (38,13 MB) |
3. Charge transport characterization of P3HT thin-film organic semiconductor : Written report: in fulfilment of diploma seminar 1FAF29 requirementMatija Filipčič, 2021, raz. nal. na višji ali visoki šoli Opis: The focus of this diploma seminar is to describe different types of charge transport theory and
models used for finding mobility in semiconductors, more specifically focused on P3HT thin-film
organic semiconductor. It also describes the time-of-flight method, which was used to measure the
experimental data for P3HT with time dependent current I(t) curve. Another data set was obtained
by performing Kinetic Monte Carlo (KMC) simulations using Miller-Abrahams hopping formalism.
KMC was used to determine the material disorder, simulate I(t) curve and transit time for every
charge carrier. Simulated data, different transit times and mobilities were then finally compared
with experimental, in order to find agreements between the two. Ključne besede: charge transport, P3HT, thin-film organic semiconductor Objavljeno v RUNG: 15.09.2021; Ogledov: 3372; Prenosov: 0 Gradivo ima več datotek! Več... |
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5. Photoelectrochemical Water Splitting Studies with nanostructured n and p-type semiconductor electrodesSaim Emin, Matjaž Valant, 2017, objavljeni povzetek znanstvenega prispevka na konferenci (vabljeno predavanje) Opis: Photoelectrochemical water splitting has been demonstrated as a promising way to efficiently split water. Currently, solar-to-hydrogen conversion efficiency using state-of-the-art material combinations in PEC system is in the order of 7%. Fabrication of nanostructured materials with unique morphologies and compositions is an important factor to fully utilize the possibilities in this field. We will present different strategies for the preparation of nanostructured metal oxide thin films by using electrodeposition and wet-chemistry techniques. Focus will be given on the preparation of ZnO and CuO thin films where intermediate phases like Zn(OH)8Cl2.H2O and CuX (X=Br, Cl) were electrodeposited. Wet-chemistry synthesis techniques will be also explored for the preparation of nanostructured WO3 and a-Fe2O3 thin films. Especially, the hot-pyrolysis technique for the preparation of colloidal W and Fe/Fe-oxide nanoparticles will be shown. Spin-coating of W and Fe/Fe-oxide NPs onto optically conductive substrates and subsequent heat treatment of the obtained films was found to be a convenient way for the preparation of nanostructured WO3 and a-Fe2O3 thin films. Ključne besede: photoelectrochemical water splitting, colloidal nanoparticles, semiconductor Objavljeno v RUNG: 24.10.2017; Ogledov: 5377; Prenosov: 0 Gradivo ima več datotek! Več... |
6. THE MORPHOLOGY DEPENDENCE ON GROWTH PARAMETERS IN NANOSTRUCTURED SEMICONDUCTORSMiha Gunde, 2014, diplomsko delo Opis: Poly(3-hexylthiophene) (P3HT) is an organic semiconductor material that is widely studied in the photovoltaics and transistor fields of research. The polymer exhibits a relatively high charge carrier mobility when the molecules are ordered in a crystalline way. In this
case the material exhibits a fibril-like morphology, which is usually studied by atomic force microscopy (AFM). Previous studies show that blending P3HT with graphene can further improve the charge carrier transport properties of the film. In this experiment, the scanning electron microscope (SEM) has been chosen, due to its practical aspects such as speed of operation and ease of use. Three sets of samples have been analyzed, containing films made of P3HT+graphene blends at different concentrations. The aims of the experiment are:
i) to find good conditions for the observation of the morphology features of the film
ii) to perform a morphological analysis of the surface of three sets of samples containing both pure P3HT, and P3HT+graphene blend, and possibly to highlight correlation between morpholgy and the charge transport properties.
Surface analysis is done by detecting the secondary electron (SE) emission, which is sensitive to topographical features of the surface. Good observation conditions were established by coating the specimen with a thin layer of conductive coating, using a high energy beam (30 keV), and tilting the sample to an angle (30 ◦ ). In two out of three of the analyzed pure P3HT films, the presence of fibrilles indicated a possibly good charge mobility, which has
been confirmed by electrical measurements using time-of-flight photoconductivity method (TOF). The presence of graphene has only slightly modified morphology of the film. Features of graphene flakes, which lie flat in the film, have been observed such as flake edges and folds. The flakes are homogeneously dispersed in the film without forming any connected network. TOF measurements have shown an increase in mobility of the charge carriers in the P3HT+graphene film. Ključne besede: scanning electron microscope, organic semiconductor thin film, P3HT, graphene, morphology Objavljeno v RUNG: 01.12.2016; Ogledov: 7572; Prenosov: 174 Celotno besedilo (30,93 MB) |
7. Electrical conductivity in 3,4,9,10-perylenetetracarboxylic dianhidride (PTCDA)Gvido Bratina, Robert Hudej, Marko Zavrtanik, John Nimly Brownell, 2001, izvirni znanstveni članek Opis: 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. Ključne besede: organic semiconductor, thin films, transient photoconductivity Objavljeno v RUNG: 10.07.2015; Ogledov: 7879; Prenosov: 41 Povezava na celotno besedilo |