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Amorphous ZrO2 and YSZ thin films with controlled microstructures were fabricated using PLD with an ArF excimer laser at room temperature, so as to attain high proton conductivity without the use of high temperature annealing. The density of the film was largely modulated from 5.9 to 1.6 g cm−3 by varying the PO2 condition during deposition. In the resulting relatively porous thin films, proton conductivity increased rapidly near room temperature with an activation energy as large as −2.5 eV, reaching 6.66 × 10−4 S cm−1 for ZrO2 and 1.38 × 10−4 S cm−1 for YSZ thin films. The proton conductivity obtained in this study was higher than that exhibited by polycrystalline YSZ pellets (∼10−5 S cm−1), even though the employed thin films were amorphous. To date, such high proton conductivity has been achieved only with polycrystalline YSZ thin films, which require the use of a high temperature annealing process. These results indicate that the origin of the high proton conductivity is attributed to variations in porosity and the local structure around Zr atoms which are controlled by the PO2 levels. The present study evidences that a solid electrolyte thin film with high proton conductivity can be fabricated at room temperature throughout the fabrication process, which in turn expands the applicability of proton-conducting solid electrolytes to a wide range of electrochemical devices. [ABSTRACT FROM AUTHOR]

To realize the continuous development of information and communication equipment, it is also important to develop devices with new operating principles that overcome the functional and performance limitations of conventional electronics devices, such as transistors made of semiconductor materials. One group of devices that hold this promise is nanoionics devices that operate by using local ion transport and electrochemical reaction in solids. A number of nanoionics devices that control nanoelectrochemical phenomena through the use of ionic nanoarchitectonics have been created. Here the use of ionic nanoarchitectonics to locally control ion transport and electrochemical reactions through the use of ion conductors or mixed conductors as device materials is described. Further, the structures of nanoionics devices created by using the nanoarchitectonics, as well as their various electrical, magnetic and optical functionalities are introduced. It is expected that such nanoionics devices will complement conventional electronics devices, and make possible the further development of information and communication technologies. [ABSTRACT FROM AUTHOR]

We investigated the effects of relative humidity (RH) in the ambient atmosphere on the resistive switching behavior of a polyethylene oxide (PEO)-based atomic switch. Current–voltage, cyclic voltammetry, and electrochemical impedance measurements were carried out on a Ag/Ag salt-included PEO/Pt device at various RH levels. It was found that the operation voltages decreased in magnitude as the RH levels increased. This behavior was explained by enhanced Ag oxidation rates at the anode, which are facilitated by counter reactions of absorbed water molecules at the cathode. Increased Ag+ ion conductivity also contributes to the decreased operation voltages at higher RH levels, which may originate from a lowering of water molecule interactions with ether groups in the polymer chains. The results show that water molecules play a crucial role in determining the switching behavior and operation voltages of polymer-based atomic switches. [ABSTRACT FROM AUTHOR]

The electric double layer (EDL) effect at solid electrolyte/electrode interfaces has been a key topic in many energy and nanoelectronics applications (e.g., all-solid-state Li+ batteries and memristors). However, its characterization remains difficult in comparison with liquid electrolytes. Herein, we use a novel method to show that the EDL effect, and its suppression at solid electrolyte/electronic material interfaces, can be characterized on the basis of the electric conduction characteristics of hydrogenated diamond(H-diamond)-based EDL transistors (EDLTs). Whereas H-diamond-based EDLT with a Li-Si-Zr-O Li+ solid electrolyte showed EDL-induced hole density modulation over a range of up to three orders of magnitude, EDLT with a Li-La-Ti-O (LLTO) Li+ solid electrolyte showed negligible enhancement, which indicates strong suppression of the EDL effect. Such suppression is attributed to charge neutralization in the LLTO, which is due to variation in the valence state of the Ti ions present. The method described is useful for quantitatively evaluating the EDL effect in various solid electrolytes. The effect of the electric double layer with solid electrolytes remains hard to characterize. In this study, the authors show how to evaluate the electric double layer effect with various lithium solid electrolytes using a hydrogenated diamond-based transistor. [ABSTRACT FROM AUTHOR]

Scandium (Sc) and yttrium (Y) co-doped ZrO2 (ScYSZ) thin films were prepared on a SiO2-Si substrate via pulsed laser deposition (PLD) method. In order to obtain good quality thin films with the desired microstructure, various oxygen partial pressures ( P O 2 ) from 0.01 Pa to 10 Pa and substrate temperatures (Ts) from 25 °C to 800 °C were investigated. X-ray diffraction (XRD) patterns results showed that amorphous ScYSZ thin films were formed at room substrate temperature while cubic polycrystalline thin films were obtained at higher substrate temperatures (Ts = 200 °C, 400 °C, 600 °C, 800 °C). Raman spectra revealed a distinct Raman shift at around 600 cm−1 supporting a cubic phase. However, a transition from cubic to tetragonal phase can be observed with increasing oxygen partial pressure. Photoemission spectroscopy (PES) spectra suggested supporting analysis that more oxygen vacancies in the lattice can be observed for samples deposited at lower oxygen partial pressures resulting in a cubic structure with higher dopant cation binding energies as compared to the tetragonal structure observed at higher oxygen partial pressure. On the other hand, dense morphologies can be obtained at lower   P O 2 (0.01 Pa and 0.1 Pa) while more porous morphologies can be obtained at higher P O 2 (1.0 Pa and 10 Pa). [ABSTRACT FROM AUTHOR]