Формирование наноразмерных пленок золота в условиях многократного автооблучения при ионно-лучевом осаждении

Gold films with a thickness of several tens of nanometers were obtained on silicon and quartz substrates by ion-beam deposition – sputtering. It is shown that the predominant lateral growth of nanoscale metal layers along the substrate surface occurs under exposure to the high-energy component of the sputtered atoms flux. The decisive role in the nanometer gold film for-mation is played by the elastic collision of sputtered metal atoms with atoms of the substrate and the growing film. The application of the manifold deposition – sputtering operation allows sup-pressing the grain formation process and obtaining gold films with better characteristics than those with a single deposition.

Experimental Measurement of Sharp THz Absorption Signatures from Nucleic Acid Solutions in Nanofluidic Channels

We report on the room-temperature experimental measurement of THz absorption signatures in aqueous, double-stranded nucleic acid solutions confined to the submicron silica channels on fused quartz substrates using THz frequency-domain (photomixing) spectroscopy. Three sharp (i.e., strong and narrow) signatures, ~10–20 GHz FWHM, are observed in the shortest base pair sample—small interfering, double-stranded (ds) RNA—in the range of 800 GHz to 1.1 THz. Three similar signatures are also observed in a 50-bp dsDNA ladder sample. For a 1-kbp dsDNA ladder sample, the three are still evident, but are broadened and weakened. For a 48.5-kbp sample (λ-DNA), no prominent signatures are observed, but rather a quasi-sinusoidal transmittance spectrum consistent with a substrate etalon effect. The division between sharp signatures and no signatures is consistent with the molecular length being shorter or longer than the persistence length.

Annealing Effect on Seebeck Coefficient of SiGe Thin Films Deposited on Quartz Substrate

Over the past few years, thermoelectrics have gained interest with regard to thermoelectricity interconversion. The improvement in the efficiency of the thermoelectric material at an ambient temperature is the main problem of research. In this work, silicon–germanium (SiGe) thin films, owing to superior properties such as nontoxicity, high stability, and their integrability with silicon technologies, were studied for thermoelectric applications. P-type SiGe thin films were deposited on quartz substrates by DC/RF magnetron sputtering and annealed at three different temperatures for 1 hour. Significant enhancement in the Seebeck coefficient was achieved for the sample annealed at 670 °C. A high power factor of 4.1 μWcm−1K−2 was obtained at room temperature.

Structural and Optical Studies of Lithium Doped Barium Titanate

This study's goals are to fabricate and analyze the microstructure and optical properties of BT and Li-doped BT as the dependence of the Li concentrations (x) of 0.05, 0.1, and 0.15. The thin films of the BT and Li-doped BT have been successfully deposited on the quartz substrates by the sol-gel method. The microstructure and optical features were characterized via XRD and UV-Vis Spectrophotometer, respectively. The XRD patterns exhibit that the lattice parameter and cell volume of the Li-doped films are bigger than that of the BT due to the existence of Li doping in the BT host structure. Additionally, the tetragonality and crystallite size of all films decrease as the more Li number with the BLTO5 has the biggest lattice strain as compared to the others. Meanwhile, the optical characterization reveals that the transmittance spectra increase and the absorption edges shift to the shorter wavelengths as the addition of Li dopant indicating the bandgap values change. In contrast, the refractive index values of the films reduce by the more Li number.

Crystallization Double-Layer Magneto-Active Films for Magnetophotonics

Magneto-optics, magnetophotonics and magnetoplasmonics stay at the edge of scientific interests last years due to their unique features to manage the light and electromagnet field. Bi-substituted iron garnet (Bi:IG) is one of most promising magneto-optical material for these applications in order to its high efficiency in visible and infrared spectra. The possibility to integrate Bi:IG films to silicon semiconductor process leads to creation nanoscale hight performance magneto-optical devices. Bi:IG structures of different composition might be deposited by vacuum deposition on different substrates. The investigation of crystallization process of Bi:IG double-layer films at a different process parameter on gadolinium gallium garnet and fused quartz substrates allowing to determine dependences and suggestions for integration Bi:IG to semiconductor process or multicomponent optical nanostructures.

ANNEALING TEMPERATURES’ EFFECTS ON MICROSTRUCTURE AND OPTICAL PROPERTIES OF Ba0.95Sr0.05TiO3 FILMS

ANNEALING TEMPERATURES’ EFFECTS ON MICROSTRUCTURE AND OPTICAL PROPERTIES OF Ba0.95Sr0.05TiO3 FILMS. Ferroelectric materials, one of which is Barium Strontium Titanate (BST), can be applied for photovoltaic. Ferroelectric films function as the P-type semiconductor in the P-N junction. BST (Ba0.95Sr0.05TiO3) films have been deposited on Pt/Si (111) and quartz substrates via the CSD method prepared by spin coater. The films were annealed at various temperatures of 800 °C, 900 °C, and 1000 °C to observe the annealing temperatures' effects on the microstructure and optical properties of the BST films. From the XRD results, the intensity of diffraction peaks gets higher along with the higher annealing temperature. It thus causes the level of crystallization and the crystal size of the Ba0.95Sr0.05TiO3 films to increase. The morphology results reveal that the grains size of the Ba0.95Sr0.05TiO3 films is getting larger with the higher annealing temperature. The optical properties examined in the Ba0.95Sr0.05TiO3 films include absorbance and bandgap energy values. Values of bandgap energy show a decrease with increasing sintering temperature. The smallest bandgap energy of the Ba0.95Sr0.05TiO3 film is achieved at 1000 °C of 3.20 eV. BST films were annealed at temperature 1000 °C attained from this study can be considered as candidate for a photovoltaic ferroelectric material.

Annealing Studies of Copper Indium Oxide (Cu2In2O5) Thin Films Prepared by RF Magnetron Sputtering

Copper indium oxide (Cu2In2O5) thin films were deposited by the RF magnetron sputtering technique using a Cu2O:In2O3 target. The films were deposited on glass and quartz substrates at room temperature. The films were subsequently annealed at temperatures ranging from 100 to 900 °C in an O2 atmosphere. The X-ray diffraction (XRD) analysis performed on the samples identified the presence of Cu2In2O5 phases along with CuInO2 or In2O3 for the films annealed above 500 °C. An increase in grain size was identified with the increase in annealing temperatures from the XRD analysis. The grain sizes were calculated to vary between 10 and 27 nm in films annealed between 500 and 900 °C. A morphological study performed using SEM further confirmed the crystallization and the grain growth with increasing annealing temperatures. All films displayed high optical transmission of more than 70% in the wavelength region of 500–800 nm. Optical studies carried out on the films indicated a small bandgap change in the range of 3.4–3.6 eV during annealing.

Substrate Temperature-Dependent Structural, Optical, and Electrical Properties of Thermochromic VO2(M) Nanostructured Films Grown by a One-Step Pulsed Laser Deposition Process on Smooth Quartz Substrates

Thermochromic M-phase vanadium dioxide VO2(M) films with different morphologies have been grown directly on smooth fused quartz substrates using low deposition rate pulsed laser deposition without posttreatment. When the substrate temperature was increased in the range 450°C–750°C, better (011) texturization of VO2(M) films was observed along with an enhancement of their crystallinity. Morphology evolved from small-grained and densely packed VO2(M) grains at 450°C to less packed micro/nanowires at 750°C. Mechanisms behind the crystallinity/morphology evolution were discussed and correlated with the effect of the temperature on the diffusion of the adatoms as well as on the V5+ valence states content in VO2(M) films. Resistivity measurements as a function of temperature revealed that the insulator-to-metal transition features of VO2(M) films (i.e., transition temperature (TIMT), resistivity variation (ΔR), hysteresis width (ΔH), and transition sharpness (ΔT)) are strongly dependent on the processing temperature. In terms of optical properties, it was found that the open (i.e., porous) structure of the films achieved at high temperature induced an improvement of their luminous transmittance. Simultaneously, the enhancement of the films crystallinity with the temperature resulted in better IR modulation ability. The present contribution provides a one-step process to control the morphology of VO2(M) films grown on smooth quartz substrates for applications as switches, memory devices, and smart windows.

Fabrication of micro-mechanical planar cantilever beam-mass structures on quartz substrates using an ECDM process

Electrochemical discharge machining (ECDM) processes have been used to realize miniature structures such as micro-channels and micro-holes on non-conductive materials such as quartz and Pyrex for a variety of applications. However, for realizing mechanical/physical sensors, actuators, energy harvesters, and resonators on glass substrates, free-standing devices with movable components such as beam-mass structures and cantilevers are required. There has been a negligible focus on developing miniature glass-based devices with movable components primarily due to the non-linear material removal rate (MRR) of the ECDM processes, requiring continuous measurement, tracking, and maintaining the working gap in the range of a few micrometers during micromachining. A couple of techniques were proposed to address maintaining a constant working gap, however, using costly equipment with complex feedback mechanisms. We report a two-stage experimental approach – without using feedback mechanisms and additional equipment – to realize micro-mechanical planar cantilever beam-mass structures on thick quartz substrates in the present work. In the first stage, the process parameters such as applied voltage, tool travel rate (TTR), and initial working gap ( Wg) are optimized for fabricating broader and deeper micro-channels using needle-shaped tools. In the second stage, using the optimized parameters, an array of micro-channels is fabricated. The cumulative depth, corresponding depth, and the width of each layer of the channels are measured, and this data is utilized for fabricating planar beam-mass structures on quartz substrates. We envisage that the experimental results of the present study would be beneficial for ECDM researchers to fabricate glass-based miniature devices with movable components without using complex tools and equipment.