Peter Petrik

Hungarian Academy of Sciences | HAS · Institute of Technical Physics and Materials Science

In the present work ZnO thin films doped with Mn and V in the same amount (2 at.%) were obtained by 5 successive depositions on Pt/Ti/SiO2/Si substrates using the sol–gel and spin coating method. Their structural, morphological, chemical, optical, and piezoelectric properties were investigated by X-Ray Diffraction (XRD), Scanning Electron Microscop...

The behavior of single layer van der Waals (vdW) materials is profoundly influenced by the immediate atomic environment at their surface, a prime example being the myriad of emergent properties in artificial heterostructures. Equally significant are adsorbates deposited onto their surface from ambient. While vdW interfaces are well understood, our...

We have investigated high temperature phase transitions in NaNbO 3 thin films epitaxially grown under tensile lattice strain on (110) DyScO 3 substrates using metal-organic vapor phase epitaxy. At room temperature, a very regular stripe domain pattern consisting of the monoclinic a 1 a 2 ferroelectric phase was observed. Temperature-dependent studi...

HfS2 has recently emerged as a promising 2D semiconductor, but the lack of a reliable method to produce continuous films on a large scale has hindered its spreading. The atomic layer deposition of the material with the precursor tetrakis-dimethylamino-hafnium with H2S is a relatively novel solution to this problem. This paper shows that it is a fac...

Incorporated hydrogen and its bonding configuration have an effect on the electrical and structural properties of hydrogenated amorphous silicon (a-Si) thin films. On one hand hydrogenization is known to be very efficient in reducing the density of dangling bonds responsible for deep levels in the bandgap; the technological process that carries out...

The structural and chemical homogeneity of the developed thin film upon color etching a low-carbon steel specimen with Beraha-I type color etchant was investigated by spectroscopic ellipsometry and electron backscatter diffraction examinations. The obtained layer thickness maps showed a good correlation with the crystallographic orientation of the...

Thin films covering large surfaces are used in a very wide range of applications from displays through corrosion resistance, decoration, water proofing, smart windows, adhesion performance to solar panels and many more. Scaling up existing thin film measurement techniques requires a high speed and the redesign of the configurations. The aim of this...

Quantum confinement of graphene carriers is an effective way to engineer its properties. It is commonly realized through physical edges that are associated with the deterioration of mobility and strong suppression of plasmon resonances. Here, we demonstrate a simple, large-area, edge-free nanostructuring technique, based on amplifying random nanosc...

Quantum confinement of the charge carriers of graphene is an effective way to engineer its properties. This is commonly realized through physical edges that are associated with the deterioration of mobility and strong suppression of plasmon resonances. Here, we demonstrate a simple, large-area, edge-free nanostructuring technique, based on amplifyi...

In this study we report on the growth of ZrO2 films upon the gradual thermal annealing of Zr in the temperature range of 500–700 K. The thickness of the oxide was monitored by in-situ spectroscopic ellipsometry with temporal and thickness resolutions of a few seconds and a few nanometers, respectively. A remarkable feature of the process was that t...

Regular monitoring of arsenic concentrations in water sources is essential due to the severe health effects. Our goal was to develop a rapidly responding, sensitive and stable sensing layer for the detection of arsenic. We have designed flagellin-based arsenic binding proteins capable of forming stable filament structures with high surface binding...

Layers and devices utilizing semiconductor nanocrystals have been the subjects of intensive research due to applications in opto- and microelectronic devices, solar cells, detectors, memories and in many more fields. We have shown previously that those nanocrystals in dielectric matrices undergo a substantial reformation during electron irradiation...

We designed a Bragg mirror structure with an SiO2 top layer to create a resonance in the ultraviolet wavelength range, near the absorption peak position of various proteins. We demonstrate that the wavelength of enhanced sensitivity can be adjusted by proper design of the 1D photonic structure. The possibility to design the wavelength of enhanced s...

Due to its remarkable switching effect in electrical and optical properties, VO2 is a promising material for several applications. However, the stoichiometry control of multivalent vanadium oxides, especially with a rational deposition technique, is still challenging. Here, we propose and optimize a simple fabrication method for VO2 rich layers by...

Gold nanoparticles (AuNPs) display surface plasmon resonance (SPR) as a result of their irradiation at a targeted light frequency. SPR also results in heat production that increases the temperature of the surrounding environment, affecting polymerization. The aim was to investigate the SPR effect of AuNPs on a dimethacrylate-based photopolymer syst...

In this work, amorphous hydrogen-free silicon nitride (a-SiNx) and amorphous hydrogenated silicon nitride (a-SiNx:H) films were deposited by radio frequency (RF) sputtering applying various amounts of hydrogen gas. Structural and optical properties were investigated as a function of hydrogen concentration. The refractive index of 1.96 was character...

Ion implantation has been a key technology in microelectronics and generally, for the controlled surface modification of materials for tribology, biocompatibility, corrosion resistance and many more. In this work in-situ spectroscopic ellipsometry was used for accurately tracking and on-line evaluating the accumulation of voids and damage in crysta...

Mid-infrared (IR) ellipsometry of thin films and molecule layers at solid–liquid interfaces has been a challenge because of the absorption of light in water. It has been usually overcome by using configurations utilizing illumination through the solid substrate. However, the access to the solid–liquid interface in a broad spectral range is also cha...

Porous gold nanoparticles (PGNs) are very popular due to their high surface/volume ratio, moreover they have stronger plasmonic properties than their solid counterparts. These properties make the porous gold nanoparticles very useful for lots of applications, for instance chemical sensors, cancer therapy applications. For applications, however, it...

The optical parameters of hydrogenated amorphous a-\(\hbox {Si}_{1-x}\,\hbox {Ge}_{{x}}\):H layers were measured with focused beam mapping ellipsometry for photon energies from 0.7 to 6.5 eV. The applied single-sample micro-combinatorial technique enables the preparation of a-\(\hbox {Si}_{1-x}\,\hbox {Ge}_{{x}}\):H with full range composition spre...

Nuclear fuel claddings can balloon and rupture at high temperatures under internal gas pressure in case of design basis accidents like loss-of-coolant-accident (LOCA). The thermal phenomena surrounding the ballooning and cracking was investigated in a series of experiments performed using zirconium alloy cladding tubes at the Centre for Energy Rese...

Protective SiC-rich nano layer was created by ion beam mixing of Si/C multilayers. The transformation of the Si and C layers into a homogeneous SiC layer was analyzed using complementary depth profiling by spectroscopic ellipsometry (SE) and Auger electron spectroscopy (AES). The distribution of elements and their chemical states was revealed by AE...

This paper reports the comparative study of piezoelectric nanostructures deposited on metallic flexible substrate versus rigid substrates as a new architecture for energy harvesters. Rigid metallic substrates are multi-layered types of Pt/Ti/SiO2/Si or Au/Ti/SiO2/Si while Ti foil is a flexible metallic substrates. The active piezo-layer consisted o...

Low-temperature evolution of optical and structural properties of Ge-rich-Al2O3 films with different Ge contents was investigated. As-deposited films and films annealed at TA≤550 °C were found to be amorphous whatever the Ge content. The formation of amorphous Ge clusters occurs at TA=550 °C, whereas their crystallization is prominent at TA=600 °C...

CrAlN alloys can play an important role in the improvement of next generation piezoelectric MEMS devices. However, enhanced piezoelectric constants require high degree of uniaxial orientation in the polycrystalline thin film. In this work, CrxAl1−xN thin films with varying compositions were deposited at different substrate temperatures by reactive...

Environmental monitoring of Ni is needed around the WHO threshold limit of 0.34 µM. This sensitivity target can usually only be met by time consuming and expensive laboratory measurements. There is a need for cheap field-applicable methods, even if it is only used for signaling the necessity of a more accurate laboratory investigation. In this work...

Accurate reference dielectric functions play an important role in the research and development of optical materials. Libraries of such data are required in many applications in which amorphous semiconductors are gaining increasing interest, such as in integrated optics, optoelectronics or photovoltaics. The preparation of materials of high optical...

NbO2 is a promising candidate for resistive switching devices due to an insulator-metal transition above room temperature, which is related to a phase transition from a distorted rutile structure to undistorted one. However, the electrical resistivity of the NbO2 thin-films produced so far has been too low to achieve high on-off switching ratios. H...

Biofunctional coatings are key elements of biosensors regulating interactions between the sensing surface and analytes as well as matrix components of the sample. These coatings can improve sensing capabilities both by amplifying the target signal and attenuating interfering signals originating from surface fouling (non-specific binding). Consideri...

Planar optical waveguides were designed and fabricated in an Er-doped Tungsten-Tellurite oxide glass and in a KDy (WO4)2 crystal by swift heavy ion irradiation. 12.5 MeV Au⁵⁺ ions were used in the first case and 10.5 MeV N⁴⁺ ions in the second one. Irradiated fluences were very low: 7·10¹⁴ ions/cm² in the first experiment, and 4·10¹⁵ ions/cm² ions/...

Homogeneous films from SiOx (x = 1.2, 1.3)were deposited on crystalline Si substrates by thermal evaporation of silicon monoxide in vacuum. A part of the films was further annealed at 1000 °C to grow Si nanocrystals in a silicon dioxide matrix. Homogeneous and composite films with initial x = 1.2 were irradiated by 20-MeV electrons at a fluence of...

Aluminum nitride (AlN) films were synthesized onto Si(100) substrates by pulsed laser deposition (PLD) in vacuum or nitrogen, at 0.1, 1, 5, or 10 Pa, and substrate temperatures ranging from RT to 800 °C. The laser parameters were set at: incident laser fluence of 3–10 J/cm2 and laser pulse repetition frequency of 3, 10, or 40 Hz, respectively. The...

To characterize zirconium surfaces in forms of tubes and plates for nuclear applications, ellipsometry has been used. It has been shown earlier that ellipsometry can be used even on the surface of tubes with a diameter of 9.1 mm, when applying proper focusing. It is also determined reference refractive indices have also been determined for both zir...

Understanding interface processes has been gaining crucial importance in many applications of biology, chemistry, and physics. The boundaries of those disciplines had been quickly vanishing in the last decade, as metrologies and the knowledge gained based on their use improved and increased rapidly. Optical techniques such as microscopy, waveguide...

Gradient a-Si1-xGex layers have been deposited by "one-sample concept" combinatorial direct current (DC) magnetron sputtering onto one-inch-long Si slabs. Characterizations by electron microscopy, ion beam analysis and ellipsometry show that the layers are amorphous with a uniform thickness, small roughness and compositions from x = 0 to x = 1 chan...

Homogeneous films from SiO1.3 (250 nm thick) were deposited on crystalline Si substrates by thermal evaporation of silicon monoxide. A part of the films was further annealed at 700 °C to grow amorphous Si (a-Si) nanoclusters in an oxide matrix, thus producing composite a-Si-SiO1.8 films. Homogeneous as well as composite films were irradiated by 20-...

Al2O3 (5 nm)/Si (bulk) sample was subjected to irradiation of 5 keV electrons at room temperature, in a vacuum chamber (pressure 1 × 10-9 mbar) and formation of amorphous SiO2 around the interface was observed. The oxygen for the silicon dioxide growth was provided by the electron bombardment induced bond breaking in Al2O3 and the subsequent produc...

The research on solar cells based on photonic, plasmonic and various nanostructured materials has been increasing in the recent years. A wide range of nanomaterial approaches are applied from photonic crystals to plasmonics, to trap light and enhance the absorption as well as the efficiency of solar cells. The first part of this chapter presents ex...

Bovine fibrinogen monolayers on thin gold films and glassy carbon substrate were investigated using grazing incidence X-ray fluorescence (GIXRF) and spectroscopic ellipsometry (SE). The aim was to determine the amount of protein and to develop models and references for the SE measurement. Both methods were capable of measuring protein amount in the...

Aluminium nitride (AlN) films were synthesized by pulsed laser ablation of poly-AlN target on Si(100) substrates using a KrF* excimer laser source (λ = 248 nm, τFWHM ≤ 25 ns), with incidence laser fluence of ~ 3 J/cm² and laser pulse repetition frequencies (LPF) of 3, 10 and 40 Hz, respectively. The depositions were performed in nitrogen pressure o...

The Kretschmann-Raether geometry is widely used to investigate the properties of various biological samples and their behavior on different substrates ###citearw11a (mostly on gold surface with/without different functionalization). In this configuration the surface plasmon polaritons (SPPs) are used to enhance the sensitivity of the measurement. Re...

The change of optical and structural properties of Ge nanoclusters in ZrO2 matrix have been investigated by spectroscopic ellipsometry versus annealing temperatures. Radio-frequency top-down magnetron sputtering approach was used to produce the samples of different types, i.e. single-layers of pure Ge, pure ZrO2 and Ge-rich-ZrO2 as well as multi-la...

Optical methods have been used for the sensitive characterization of surfaces and thin films for more than a century. The first ellipsometric measurement was conducted on metal surfaces by Paul Drude in 1889. The word 'ellipsometer' was first used by Rothen in a study of antigen-antibody interactions on polished metal surfaces in 1945. The 'bible'...

Carboxymethyl dextran (CMD) layers were fabricated on optical waveguide sensor chips by spin coating technique. The dependence of the layer thickness on the rotational speed as a technical parameter of the fabrication process, was investigated by spectroscopic ellipsometry. Optical model for the evaluation of the ellipsometric data was developed an...

A novel technique for rare-earth doping in silica is developed with femtosecond laser plasma processing and record high concentration of erbium in silica/ silica-on-silicon platforms to realize compact optical amplifiers for silicon photonics are achieved.

Columnar mesoporous Si thin films and dense nanowire (SiNW) carpets were investigated by spectroscopic ellipsometry in the visible-near-infrared wavelength range. Porous Si layers were formed by electrochemical etching while structural anisotropy was controlled by the applied current. Layers of highly oriented SiNWs, with length up to 4.1 μm were s...

Optical properties of Zr and its oxide have been measured on the surface of nuclear fuel cladding tubes. It has been shown that ellipsometry with focusing can routinely be used to measure thin layers and surface properties on Zr tubes with a diameter as small as 9.1 mm. Multi-sample and depth profiling models have been used to determine reference d...

Substrate surface damage induced by deposition of metal atoms by radiofrequency (rf) sputtering or ion beam sputtering onto single-crystalline silicon (c-Si) surface has been characterized earlier by electrical measurements. The question arises whether it is possible to characterize surface damage using spectroscopic ellipsometry (SE). In our exper...

Two surface-sensitive label-free optical methods, grating coupled interferometry (GCI) and spectroscopic ellipsometry (SE) were integrated into a single instrument. The new tool combines the high sensitivity of GCI with the spectroscopic capabilities of SE. This approach allows quantification with complex optical models supported by SE and accurate...

Plasmon-enhanced in situ spectroscopic ellipsometry was realized using the Kretschmann geometry. A 10-μL flow cell was designed for multi-channel measurements using a semi-cylindrical lens. Dual-channel monitoring of the layer formation of different organic structures has been demonstrated on titania nanoparticle thin films supported by gold. Compl...

This paper suggests the evaluation of morphological parameters of porous silicon layers (PSL) using spectroscopic ellipsometry from UV to mid-infrared optical range. PSL were prepared by electrochemical etching of monocrystalline silicon wafers in hydrofluoric acid-based electrolyte. Measuring with an optical and an infrared ellipsometer with a wid...