A5009900862- Photonic Crystals and Applications
- Photonic and Optical Devices
- Semiconductor Quantum Structures and Devices
- Optical Coatings and Gratings
- Chalcogenide Semiconductor Thin Films
- Plasmonic and Surface Plasmon Research
- Metamaterials and Metasurfaces Applications
- Organic Electronics and Photovoltaics
- Quantum Dots Synthesis And Properties
- 3D IC and TSV technologies
- Conducting polymers and applications
- Nanofabrication and Lithography Techniques
- Optical Polarization and Ellipsometry
- Spectroscopy and Quantum Chemical Studies
- Advanced Semiconductor Detectors and Materials
- Electronic Packaging and Soldering Technologies
- Semiconductor materials and interfaces
- Gold and Silver Nanoparticles Synthesis and Applications
- Advanced Chemical Physics Studies
- Nonlinear Optical Materials Research
- Copper Interconnects and Reliability
- Advanced Antenna and Metasurface Technologies
- GaN-based semiconductor devices and materials
- Semiconductor materials and devices
- Surface Roughness and Optical Measurements
Johannes Kepler University of Linz
2015-2024
Profactor (Austria)
1997-2015
University of Belgrade
2015
Iowa State University
2015
Ames National Laboratory
2015
Christian Doppler Laboratory for Thermoelectricity
2003-2014
Medical University of Graz
2014
University of Leeds
2009
Institute of Physics Belgrade
2009
Roma Tre University
2007
This paper discusses the fundamentals, applications, potential, limitations, and future perspectives of polarized light reflection techniques for characterization materials related systems devices at nanoscale. These include spectroscopic ellipsometry, polarimetry, reflectance anisotropy. We give an overview various ellipsometry strategies measurement analysis nanometric films, metal nanoparticles nanowires, semiconductor nanocrystals, submicron periodic structures. show that is capable more...
Abstract Semitransparent inverted organic photodiodes are fabricated with a Baytron PH500 ethylene‐glycol layer/silver grid as the top electrode. Reasonable performances obtained under both rear‐ and front‐side illumination efficiencies up to 2% achieved. Some light is shed on visual prospects through optical simulations for semitransparent device of poly(3‐hexylthiophene) (P3HT) C60 derivative 1‐(3‐methoxycarbonyl)propyl‐1‐phenyl[6,6]C 71 (PC70BM) in structure. These calculations allow...
Abstract Carbon bridged (C‐PCPDTBT) and silicon‐bridged (Si‐PCPDTBT) dithiophene donor–acceptor copolymers belong to a promising class of low bandgap materials. Their higher field‐effect mobility, as high 10 −2 cm 2 V −1 s in pristine films, their more balanced charge transport blends with fullerenes make materials better candidates for use photovoltaic devices. Striking morphological changes are observed polymer:fullerene bulk heterojunctions upon the substitution bridging atom. XRD...
The realization of highly efficient organic solar cells requires the understanding and optimization light path in photoactive layer. We present this article our approach to measure model optical properties bulk-heterojunction devices, control them order enhance photovoltaic performances. report recent observations on dependence external quantum efficiency (EQE) incidence angle light, results determination internal based EQE measurement modeling cross-checked by reflection measurements....
Reducing the temperature needed for high strength bonding which was and is driven by need to reduce effects of coefficient thermal expansion mismatch, budgets, increase throughput has led development plasma treatment procedures capable Si wafers below 300 °C with a bond equivalent bulk. Despite being widely used, physical chemical mechanisms enabling low wafer have remained poorly understood. We developed an understanding beneficial surface modifications model based on short range diffusion...
Engineering of a refractive index profile is powerful method for controlling electromagnetic fields. In this paper, we investigate possible realization isotropic gradient media at optical frequencies using two-dimensional graded photonic crystals. They consist dielectric rods with spatially varying radii and can be homogenized in broad frequency range within the lowest band. Here they operate metamaterial regime, that is, crystals are described effective so regarded as low-loss broadband...
Abstract Charge transport and recombination are studied for organic solar cells fabricated using blends of polymer poly[(4,4′‐bis(2‐ethylhexyl)dithieno[3,2‐b:2′,3′‐d]silole)‐2,6‐diyl‐alt‐(4,7‐bis(2‐thienyl)‐2,1,3‐benzothiadiazole)‐5,5′‐diyl] (Si‐PCPDTBT) with [6,6]‐phenyl‐C 61 ‐butyric acid methyl ester (mono‐PCBM) the bis‐adduct analogue mono‐PCBM (bis‐PCBM). The photocurrent Si‐PCPDTBT:bis‐PCBM devices shows a strong square root dependence on effective applied voltage. From relationship...
Antimony sulfide, Sb
We have carried out detailed optical simulations of tandem solar cells based on the following organic semiconductors: poly(3-hexylthiophene) (P3HT), poly[2,6-(4,4-bis-(2-ethylhexyl)-4H- cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT), 1-(3- methoxycarbonyl) propyl-1-phenyl[6,6] C61 (PC60BM), and 1-(3-methoxycarbonyl) propyl-1- phenyl[6,6] C71 (PC70BM). demonstrate that many possible combinations component materials, one specific combination emerges as best to...
Inverted bulk-heterojunction organic solar cells (OSCs) using solution-processed layers possess significant advantages compared to the usual noninverted devices. To investigate full potential of this type OSC, we have carried out some optical modeling by rigorous coupled wave analysis. The influence thickness several different in device has been quantified, as well maximum possible number photons absorbed poly(3-hexyltiophene):[6,6]-phenyl-C61-butyric acid methyl ester active layer for both...
The optical properties and electrical conductivity of highly conducting poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonate) (PSS) are reported as a function the processing additive conditions. addition dimethyl sulfoxide (DMSO) increases modifies dielectric response observed from ellipsometric studies. Also surface roughness morphology change composition PEDOT:PSS:DMSO film deposition real part becomes negative in samples, indicating presence delocalized charge...
The role of graphene in enabling deoxidation silver nanostructures, thereby contributing to enhance plasmonic properties and improve the temporal stability graphene/silver hybrids for both general meta‐materials applications, as well surface enhanced Raman scattering (SERS) substrates, is demonstrated. chemical mechanism occurring at graphene–silver oxide interface based on reduction triggered by that acts a shuttle electrons kind catalyst deoxidation. A formulated, combining elements...
We demonstrate for the first time a fast and easy nanoimprint lithography (NIL) based stacking process of negative index structures like fishnet Swiss-cross metamaterials. The takes few seconds, is cheap produces three-dimensional (3D) materials (NIMs) on large area which suitable mass production. It can be performed all common substrates even flexible plastic foils. This work therefore an important step toward novel breakthrough applications NIMs such as cloaking devices, perfect lenses...
The study of the physical mechanisms driving Cu-Cu wafer bonding allowed for reducing temperatures below 200 °C. Metal thermo-compression results obtained at such low are very encouraging and suggest that process is possible even room temperature if some boundary conditions fulfilled. Sputtered (PVD) electroplated Cu thin layers were investigated, analysis both metallization techniques demonstrated importance decreasing surface roughness. For an equal roughness, PVD wafers could be further...
Interest in layered van der Waals semiconductor gallium monosulfide (GaS) is growing rapidly because of its wide band gap value between those two-dimensional transition metal dichalcogenides and insulating materials such as hexagonal boron nitride. For the design envisaged optoelectronic, photocatalytic photonic applications GaS, knowledge dielectric function fundamental. Here we present a combined theoretical experimental investigation crystalline 2H-GaS from monolayer to bulk....
From the reflectance expressions for a thin biaxial layer on an isotropic substrate we relate reflectance-difference spectroscopy (RDS), surface photoabsorption (SPA), and spectroellipsometry. Using these results our recently acquired RD database, determine reconstructions present during flow-modulated organometallic chemical vapor growth of epitaxial GaAs from SPA data that were published by others.
Graphene is emerging as a promising material for plasmonics applications due to its strong light-matter interactions, most of which are theoretically predicted but not yet experimentally realized. Therefore, the integration plasmonic nanoparticles create metal nanoparticle/graphene composites enables numerous phenomena important range from photonics catalysis. For these it articulate coupling photon-based excitations such interaction between plasmons in each components, well their...
We present a new way to enhance the electron-phonon coupling constant and critical superconducting temperature of graphene, significantly beyond all reported values. Using density functional theory, we explore application effects tensile biaxial strain on lithium intercalated graphene. Both together, presence adatom strain, trigger enhancement temperature, up 300\%, compared non-strained
An important issue in construction of organic photovoltaic cells concerns the selective contacts. Here, especially modification hole-extraction is challenging, as energy levels have to match polymer's highest occupied molecular orbital (HOMO). We took view mutual anode interface and we sought for a solution-based alternative commonly used PEDOT:PSS – with an eye on improving inorganic interlayer. present copper iodide (CuI) versatile p-type semiconductor that meets requirements enhanced...
Conductive polymers represent a rare case in which free‐carrier absorption is shifted to the far‐infrared—an attractive advantage light of requirement highly transparent conductors across visible and near‐infrared. Unfortunately, prior approaches doping these polymers—imperative for high conductance—have consistently led strong localization arising from fluctuating band alignment among polymer chains. Here, this study overcomes problem doping‐induced Anderson first time by developing new...
We have carried out comprehensive studies of the nitrogen-induced modifications electronic structure ${\mathrm{In}}_{y}{\mathrm{Ga}}_{1\ensuremath{-}y}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$ alloys. Temperature- and composition-dependent optical absorption spectra been measured on free-standing layers thin films lattice matched to GaAs with $0<~x=3y<~0.025$ in photon energy range 0.8--2.5 eV. The measurements provided information transitions at \ensuremath{\Gamma} point Brillouin...