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The crystalline structure and electrical response of La-doped HfO2-ZrO2 thin films of which processing temperature did not exceed 400 °C were examined, where the La-doping concentration was varied from zero to ≈2 mol. %. The film structure and associated properties were found to vary sensitively with the minute variation in the La-concentration, where the ferroelectric response at low La-concentration (<≈1 mol. %) gradually became antiferroelectric-like for La-concentration >≈1 mol. %, which was accompanied by a significant increase in dielectric permittivity. La-doping was found to be very effective in inhibiting the monoclinic phase formation and in decreasing the leakage current. Notably, the high coercive field, which was one of the most significant problems in this material system, could be decreased by ∼35% at the most promising La-concentration of 0.7 mol. %. As a result, a highly promising field cycling endurance up to 1011 cycles could be secured while maintaining a high remnant polarization value (≥25 μC/cm2). This is one of the best results in this field of the authors' knowledge. [ABSTRACT FROM AUTHOR]

The influence of La content on the ferroelectric properties of HfO2-ZrO2 thin films was examined for integrated electrostatic supercapacitor applications. A transition from ferroelectric to antiferroelectric-like behavior, accompanied by a significant increase of energy storage density value and efficiency, was observed with the increasing La concentration in La-doped HfO2-ZrO2-based capacitor structures, where the processing temperature remained below 400 °C. The combination of high energy storage density value (≈50 J/cm3) with high efficiency (70%) was obtained for the film with the highest La content (2.0 mol. %). The 2.0 mol. % La-doped HfO2-ZrO2-based capacitor structures were field cycled up to 109 times and were found to provide >40 J/cm3 energy storage density along with up to 80% efficiency. Moreover, the high thermal stability of such capacitors was confirmed. The founded property combination makes the La-doped HfO2-ZrO2 thin films suitable for integrated energy storage and pulse-power devices. [ABSTRACT FROM AUTHOR]

Noble transition metal dichalcogenides (TMDCs) such as PtS2 and PtSe2 show significant potential in a wide range of optoelectronic and photonic applications. Noble TMDCs, unlike standard TMDCs such as MoS2 and WS2, operate in the ultrawide spectral range from ultraviolet to mid-infrared wavelengths; however, their properties remain largely unexplored. Here, we measured the broadband (245–3300 nm) optical constants of ultrathin PtS2 and PtSe2 films to eliminate this gap and provide a foundation for optoelectronic device simulation. We discovered their broadband absorption and high refractive index both theoretically and experimentally. Based on first-principle calculations, we also predicted their giant out-of-plane optical anisotropy for monocrystals. As a practical illustration of the obtained optical properties, we demonstrated surface plasmon resonance biosensors with PtS2 or PtSe2 functional layers, which dramatically improves sensor sensitivity by 60 and 30%, respectively. [ABSTRACT FROM AUTHOR]

A mild N2O plasma treatment technique (low power and low substrate temperature) for carbon materials' (including graphite and carbon nanotubes) functionalization followed by subsequent high-k dielectric atomic layer deposition (ALD) was developed. It was shown that N2O plasma carbon functionalization leads to the formation of epoxide and carboxylic groups on the carbon surface which act as active centers for ALD and, as a result, conformal and uniform Al2O3 and TixAl1-xOy films' growth occurred on the carbon surfaces. It was shown that the electrical properties of multinary TixAl1-xOy oxides are more promising in comparison to single Al2O3 oxide. Some electrical properties of the TixAl1-xOy films observed were a high dielectric constant ∼19, low leakage current density (<3 × 10-5 A/cm2 at 1 MV/cm), and high breakdown field (∼5.5 MV/cm). [ABSTRACT FROM AUTHOR]

Сombining the sol–gel method and pen plotter printing, using the hydrolytically active heteroligand complex [Co(C 5 H 7 O 2) 2-x (C 4 H 9 O) x as a component of a new functional ink, Co 3 O 4 thin films were produced on the surface of substrates of various types. The influence of synthesis conditions and print modes on the microstructure, optical, electrophysical and sensor properties of planar nanomaterials was comprehensively studied. The optical band gap energies associated with charge transfer for transitions O2-→Co3+ and O2-→Co2+ of the obtained thin films were evaluated. Using Kelvin probe force microscopy and impedance spectroscopy, the electrophysical characteristics (the electronic work function of the film surface, the temperature dependence of electrical conductivity, and the activation energy of electrical conductivity) of the obtained Co 3 O 4 films were determined. The sensitivity of printed cobalt(II, III) oxide thin films with respect to various gases (Н 2 , СН 4 , СО and NO 2) was studied. It was established that the obtained samples demonstrated the highest sensor response when detecting CO and NO 2 in the operating temperature range of 150–200°С. The prospects of the proposed synthesis method and printing technology when forming Co 3 O 4 thin-film nanostructures to create electrodes of supercapacitors and receptor components of resistive CO and NO 2 gas sensors were shown. Image 1 • A technology for pen plotter printing of Co 3 O 4 thin films using [Co(C 5 H 7 O 2) 2-x (C 4 H 9 O) x as a precursor has been developed. • The influence of print settings on the microstructure and optical properties of the produced films has been studied. • Electrophysical properties of the Co 3 O 4 films have been studied by impedance spectroscopy and Kelvin probe force microscopy. • The sensor properties of printed Co 3 O 4 thin films have been studied when detecting CO and NO 2. [ABSTRACT FROM AUTHOR]