Electrical and dielectric parameters in TiO2-NW/Ge-NW heterostructure MOS device synthesized by glancing angle deposition technique.

This paper reports the catalyst-free coaxial TiO2/Ge-nanowire (NW) heterostructure synthesis using the glancing angle deposition (GLAD) technique integrated into an electron beam evaporator. The frequency and voltage dependence of the capacitance-voltage (C-V) and conductance-voltage (G/ω-V) characteristics of an Ag/TiO2-NW/Ge-NW/Si device over a wide range of frequency (10 kHz-5 MHz) and voltage (- 5 V to + 5 V) at room temperature were investigated. The study established strong dependence on the applied frequency and voltage bias. Both C-V and G/ω-V values showed wide dispersion in depletion region due to interface defect states (Dit) and series resistance (Rs). The C and G/ω value decreases with an increase in applied frequency. The voltage and frequency-dependent Dit and Rs were calculated from the Hill-Coleman and Nicollian-Brews methods, respectively. It is observed that the overall Dit and Rs for the device decrease with an increase in the frequency at different voltages. The dielectric properties such as dielectric constant ([Formula: see text]'), loss ([Formula: see text]″) and loss tangent (tan δ) were determined from the C-V and G/ω-V measurements. It is observed that [Formula: see text]', [Formula: see text]″ decreases with the increase in frequency. Therefore, the proposed MOS structure provides a promising alternative approach to enhance the device capability in the opto-electronics industry.

Scalable Fabrication of Organic Single-Crystalline Wafers for Reproducible TFT Arrays.

Building on significant developments in materials science and printing technologies, organic semiconductors (OSCs) promise an ideal platform for the production of printed electronic circuits. However, whether their unique solution-processing capability can facilitate the reliable mass manufacture of integrated circuits with reasonable areal coverage, and to what extent mass production of solution-processed electronic devices would allow substantial reductions in manufacturing costs, remain controversial. In the present study, we successfully manufactured a 4-inch (c.a. 100 mm) organic single-crystalline wafer via a simple, one-shot printing technique, on which 1,600 organic transistors were integrated and characterized. Owing to their single-crystalline nature, we were able to verify remarkably high reliability and reproducibility, with mobilities up to 10 cm2 V-1 s-1, a near-zero turn-on voltage, and excellent on-off ratio of approximately 107. This work provides a critical milestone in printed electronics, enabling industry-level manufacturing of OSC devices concomitantly with lowered manufacturing costs.