Egon Pavlica

University of Nova Gorica · Laboratory of Organic Matter Physics

Contact resistance is a multifaceted challenge faced by the 2D materials community. Large Schottky barrier heights and gap-state pinning are active obstacles that require an integrated approach to achieve the development of high-performance electronic devices based on 2D materials. In this work, we present semiconducting PtSe2 field effect transist...

Water surfaces catalyze some organic reactions more effectively, making them unique for 2D organic material synthesis. This report introduces a new synthesis method via surfactant-monolayer-assisted interfacial synthesis on water surfaces for ring-opening polymerization of pyrrole, producing distinct polypyrrole derivatives with polyacetylene backb...

Tungsten diselenide (WSe2) has emerged as a promising ambipolar semiconductor material for field-effect transistors (FETs) due to its unique electronic properties, including a sizeable band gap, high carrier mobility, and remarkable on–off ratio. However, engineering the contacts to WSe2 remains an issue, and high contact barriers prevent the utili...

Using atomic force microscopy, we probed the growth of pentacene molecules on graphene that was fabricated by chemical vapor deposition and transferred onto 300 nm-thick SiO2 substrates. The topography of such graphene has two important properties. First, its surface is comprised of folds that have different orientations, and second, it has several...

Charge transport through a randomly oriented multilayered network of two-dimensional (2D) Ti3C2Tx (where Tx is the surface termination and corresponds to O, OH and F) was studied using time-of-flight photoconductivity (TOFP) method, which is highly sensitive to the distribution of charge carrier velocities. We prepared samples comprising Ti3C2Tx wi...

The influence of P3HT:PCBM ratio on thermal and transport properties of solar cells were determined by photothermal beam deflection spectrometry, which is advantageous tool for non-destructively study of bulk heterojunction layers of organic solar cells. P3HT:PCBM layers of different P3HT:PCBM ratios were deposited on top of PEDOT:PSS/ITO layers wh...

The combination of ecologically acceptable polysaccharide (chitosan) and graphene oxide (GO) nanoparticles was used to produce the cell membrane for a direct alkaline ethanol fuel cell (DAEFC). Due to its great power efficiency and minimal influence on the environment, this kind of fuel cell has a lot of potential uses. Recently, the performance of...

Semiconducting mesocrystalline bulk polymer specimens that exhibit near-intrinsic properties using channel-die pressing are demonstrated. A predominant edge-on orientation is obtained for poly(3-hexylthiophene-2,5-diyl) (P3HT) throughout 2 mm-thick/wide samples. This persistent mesocrystalline arrangement at macroscopic scales allows reliable evalu...

Introduction Meat consumption has been steadily increasing since the 1960s ¹ . As living standards and income levels rise, more people include meat into their diet. Although an important source of nutrients, livestock production has a negative influence on greenhouse gas emissions, water consumption, water pollution, and more, with cattle being the...

Introduction As human world population is expected to reach 9.8 billion by the year 2050 [1], the consumption of animal products is also expected to increase by a large margin, including dairy and meat. Therefore, improving the feed nutrients convergence to final products in a sustainable way is highly needed. One approach is diagnosing animal dise...

Organic transistors are key elements for flexible, wearable, and biocompatible logic applications. Multiresponsivity is highly sought-after in organic electronics to enable sophisticated operations and functions. Such a challenge can be pursued by integrating more components in a single device, each one responding to a specific external stimulus. H...

The recent success of non-fullerene acceptors in organic photovoltaics also entails a change in the requirements to the polymer donor in terms of optical and morphological properties leading to a demand for novel conjugated polymers. Herein, we report on the synthesis of a 1,4-bis-(thiophene-2-yl)-pyrrolopyridazinedione based copolymer with 2-ethyl...

The recent success of non-fullerene acceptors in organic photovoltaics also entails a change in the requirements to the polymer donor in terms of optical and morphological properties leading to a demand for novel conjugated polymers. Herein, we report on the synthesis of a 1,4-bis-(thiophene-2-yl)-pyrrolopyridazinedione based copolymer with 2-ethyl...

Graphene field-effect transistor structures were used to investigate the role of molecular alignment on charge transport properties of heterostructures comprising a single-layer graphene and variable thickness of N,N′-bis(n-octyl)-(1,7&1,6)-dicyanoperylene-3,4:9,10-bisdicarboximide (PDI8-CN2) - an n-type organic semiconductor. Our atomic force micr...

High concentrations of histamine are associated with subacute ruminal acidosis, a common disease in high-producing lactating dairy cows. Therefore, the accurate detection of low histamine levels is a strategy to monitor and diagnose ruminal acidosis in early stages. In this letter, we have developed an impedimetric histamine biosensor based on an o...

We have examined the effect of the addition of graphene nanoflakes (GNs) to improve the field-effect mobility of poly(3-hexylthiophene) (P3HT)-based field-effect transistors (FETs). We observe that the FET mobility increases up to 0.02 cm²/Vs at GNs concentration of 0.06 mg/mL. The remarkable increase in FET mobility can be ascribed to the incorpor...

Present work describes a novel polymer based nanocomposite anionic exchange membranes (AEMs) with improved features for direct alkaline fuel cell applications. AEMs based on chitosan (CS), magnesium hydroxide (Mg(OH)2) and graphene oxide (GO) with benzyltrimethylammonium chloride (BTMAC), as the hydroxide conductor, were fabricated by a solvent cas...

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 effect of 1-pyrenesulfonicacid sodium salt (1-PSA), tetracyanoethylene (TCNE) and tetrafluoro-tetracyanoquinodimethane (F4-TCNQ) on charge transport properties of reduced graphene oxide (RGO) is examined by measuring the transfer characteristics of field-effect transistors and co-planar time-of-flight photocurrent technique. Evidence of p-type...

This paper describes a study on the charge transport in a composite of liquid‐exfoliated graphene nanoparticles (GNPs) and a polythiophene semiconducting polymer. While the former component is highly conducting, although it consists of isolated nanostructures, the latter offers an efficient charge transport path between the individual GNPs within t...

The paper reviews recent advances in characterisation of charge carrier transport in organic semiconductor layers by time-of-flight photocurrent measurements, with the emphasis on the measurements of the samples with co-planar electrodes. These samples comprised an organic semiconductor layer whose thickness is on the order of a μm or less, and thu...

We used time-of-flight photocurrent measurements to determine the role of grain boundaries in charge carrier transport in thin layers of methyl ammonium lead iodide (CH3NH3PbI3). The measurement results were compared to Kinetic Monte Carlo simulations, based on a transport model, which disentangles the transport within crystallites and hopping acro...

In article number 1801181, Lei Zhang, Emanuele Orgiu, Paolo Samorì, and co‐workers develop an unprecedented device architecture operating as a high‐performance bicrystal photovoltaic detector. In the self‐suspended nanomesh scaffold, supported on a flexible plastic substrate, each semiconductor crystal is preferentially connected to the cathode and...

Despite the recent progress and enormous potential of fullerene-free organic solar cells with power conversion efficiency values exceeding 13%,[1] the molecular weight dependence of the conjugated polymer in bulk-heterojunction blend systems with small molecule-type non-fullerene electron acceptors has not been examined so far. This work highlights...

Self‐standing nanostructures are of fundamental interest in materials science and nanoscience and are widely used in (opto‐)electronic and photonic devices as well as in micro‐electromechanical systems. To date, large‐area and self‐standing nanoelectrode arrays assembled on flexible substrates have not been reported. Here the fabrication of a hollo...

Charge-carrier mobility has been investigated by time-of-flight (TOF) transient photocurrent in a lateral transport configuration in highly crystalline thin films of 2,7-dioctyl[1]benzothieno [3,2-b][1] benzothiophene (C8-BTBT) grown by a zone-casting alignment technique. High TOF mobility has been revealed that it is consistent with the delocalize...

Recent advances in the development of non-fullerene acceptors have increased the power conversion efficiency of organic solar cells to approximately 13%. Fullerene-derivatives and non-fullerene acceptors possess distinctively different structural, optical and electronic properties, which also changes the requirements on the polymer donor in non-ful...

Photoconductivity spectra measured in non-crystalline corannulene thin layers are compared to optical absorption in solution phase and thin films. The unexpected enhanced photoconductivity is correlated with GW–BSE theoretical predictions of corannulene gas-phase excitonic spectra. Theoretical analysis reveals a consistent contribution involving tr...

We demonstrate that the degree of charge delocalization has a strong impact on polarization energy and thereby on the position of the transport band edge in organic semiconductors. This gives rise to long-range potential fluctuations, which govern the electronic transport through delocalized states in organic crystalline layers. This concept is emp...

We have studied submonolayer coverages of N,N-1H,1H-perfluorobutyl dicyanoperylenecarboxydiimide (PDIF-CN2) on mechanically exfoliated graphene transferred onto SiO2 substrates. Our atomic force microscopy (AFM) data show that PDIF-CN2 forms irregularly-shaped 1.4 nm-high islands. From the selected area diffraction performed with transmission elect...

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 thro...

Crystalline dioctyl-3,4,9,10-perylenedicarboximide nanowires and 6,13-bis(triisopropylsilylethynyl) pentacene microplates are integrated into a vertical-yet-open asymmetrical heterojunction for the realization of a high-performance organic photovoltaic detector, which shows fast photoresponse, ultrahigh signal-to-noise ratio, and high sensitivity t...

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 nanowi...

Organic nanomaterials are attracting a great deal of interest for use in flexible electronic applications such as logic circuits, displays and solar cells. These technologies have already demonstrated good performances, but flexible organic memories are yet to deliver on all their promise in terms of volatility, operational voltage, write/erase spe...

A hybrid titania-silica cold-setting sol has been developed that can be deposited onto a wide variety of surfaces without the need for high-temperature fixing and that is suitable for material printing deposition. Thin hybrid titania-silica coatings were patterned onto glass and PET substrates by inkjet printing. Well-defined hybrid titania-silica...

Organic thin-film transistor transfer characteristics and time-of-flight (TOF) photoconductivity measurements were used to investigate the effect of the addition of liquid-phase exfoliated graphene nanoflakes (GNs) on the electron mobility in thin films of N,N'-1H,1H-perfluorobutyl dicyanoperylene-carboxydi-imide (PDIF-CN2). Transfer characteristic...

Atomic force microscopy has been used to examine early stages of pentacene growth on exfoliated single-layer graphene transferred onto SiO2 substrates. We have observed two-dimensional growth with mean height of 1.5±0.2 nm on as-transferred graphene. Three- dimensional islands of pentacene with average height of 11±2 nm were observed on graphene th...

Photocatalytic properties of titanium (IV) oxide (TiO2) in anatase form can be used for various purposes, including photocatalytic purification of water. For such an application, suspended or fixed photocatalytic reactors are used. Those with fixed phase seem to be preferred due to some advantages, one of which is the avoidance of photocatalyst fil...

TiO 2 thin films used as photocatalysts in environmental applications were studied by beam deflection spectroscopy (BDS) and by atomic force microscopy. A novel multiparameter theoretical model was developed in order to explain BDS experimental data. The fundamental parameters of examined films: thermal diffusivity, thermal conductivity, and charge...

A π-conjugated tetrathiafulvalene-fused perylenediimide (TTF-PDI) molecular dyad is successfully used as a solution-processed active material for light sensitive ambipolar field-effect transistors with balanced hole and electron mobilities. The photo-response of the TTF-PDI dyad resembles its absorption profile. Wavelength-dependent photoconductivi...

The rich phase behavior of 5,11-bis(triethylsilylethynyl) anthradithiophene (TES ADT) – one of the most promising, solution-processable small-molecular organic semiconductors – is analyzed, revealing the highest performing polymorph among four solid-state phases, opening pathways toward the reliable fabrication of high-performance bottom-gate/botto...

Folds in graphene—grafolds are frequently present even after transferring graphene layers, which were fabricated by chemical vapor deposition (CVD), onto SiO2 substrates. As we are showing in the present Letter, grafolds have a crucial role in determining the morphology of pentacene layers on graphene, and should be as such considered in designing...

We have examined by scanning probe microscope submonolayer coverages of pentacene on graphene fabricated by chemical vapor deposition (CVD) and exfoliated graphene. Inherent to CVD-graphene, even upon transferring onto SiO2 substrates is the presence of varying surface density of folds-grafolds. By means of Kelvin force microscopy we observe about...

Time-of-flight measurements of the photocurrent in thin organic semiconductor layers represent an effective way to extract charge carrier mobility. A common method to interpret the time-dependence of the photocurrent in these material systems assumes a position-independent electric field between two coplanar electrodes. In this letter, we compare t...

Organic semiconductors are suitable candidates for printable, flexible and large-area electronics. Alongside attaining an improved device performance, to confer a multifunctional nature to the employed materials is key for organic-based logic applications. Here we report on the engineering of an electronic structure in a semiconducting film by blen...

Here, we report a simple, alternative route towards high-mobility structures of the small-molecular semiconductor 5,11-bis(triethyl silylethynyl) anthradithiophene that requires one single processing step without the need for any post-deposition processing. The method relies on careful control of the casting temperature of the semiconductor and all...

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Export Date: 24 April 2012, Source: Scopus

Cited By (since 1996): 3, Export Date: 24 April 2012, Source: Scopus

The synthesis of four new TTF derivatives bearing phthalimides and fluorinated alkyl moieties as potential ambipolar semiconductors is described. The presence of such electron-withdrawing groups permits the stabilization of the energy of HOMO and LUMO orbitals. The solid-state structures of these novel molecules have been characterized by X-ray dif...

Organic thin film transistors were fabricated by vacuum evaporation of pentacene using different growth conditions in order to tune the pentacene layer morphology. We have performed in situ transport measurements on completed samples, and ex situ morphological characterization by atomic force microscopy. Electric properties of the microscopic inter...

We have systematically investigated the role of SiO2 surface treatment on pentacene morphology at the metal/pentacene interface prior to vacuum deposition of the pentacene layer onto OTFT structures. The substrates included as grown SiO2 and SiO2 surface treated by self-assembled monolayer (SAM) of hexamethyldislazane (HMDS). The resulting OTFT’s w...

We have used the Shockley–Ramo theorem to calculate the displacement current of drifting charge carriers in bottom-contact organic thin-film transistors (OTFTs). The displacement current is quantified in terms of the weighting field of the sensing electrode. We demonstrated that for the transistors, with dielectric thickness below 100 nm and channe...

The hopping model of charge-carrier transport coupled to the Monte Carlo simulations was used to predict the time evolution of the photoinduced charge-carrier current, I (t ), through a layer of an organic semiconductor. Two electric-field configurations inside the layer were considered: a uniform electric field and the electric field due to the in...

The organic-semiconductor-based all-solid-state photoelectrochemical cells were studied. The solid-state solar cells comprising dye-sensitized nanostructured SnO and vacuum-evaporated 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) layers exhibited significant photoresponse. Despite of unfavorable electronic energy level alignment at the dye/...