SeO2 microwires designed as low temperature abrupt microelectronic switches, negative resistance and negative dielectric constant sources

Abstract

Herein, the structural, morphological, compositional, and electrical properties of SeO2 microwires are studied and analyzed. Microwires of SeO2 of dimensions of 460×30×30 (μm)3 are electrically characterized in the temperature range of 17-300 K. SeO2 microwires are observed exhibiting nano-crystalline structure relating to a tetragonal phase. The microwires contained excess oxygen leading to some Se vacancies. The current-voltage characteristics of the microwires displayed temperature dependent abrupt switching property revealing an “ON/OFF” current ratios of ∽90 at threshold voltage of 0.48 V at 300 K. These features of the microwires remained down to 250 K. In addition, the temperature dependent electrical resistivity measurement showed that the microwires perform as a degenerate (metal like) semiconductors with quadratic temperature dependence (ρ(T)∝T2). Moreover, impedance spectra analysis has shown that SeO2 microwires exhibit negative resistance and negative dielectric constant effects in the spectral ranges of 20-1800 MHz. The work here indicate that SeO2 microwires can perform much better than powders in pellets form or in thin film form. The resonance-antiresonance of dielectric constant and abrupt switching properties are accounted as remarkable features of the SeO2 microwires nominating them as abrupt electronic switches and signal amplifiers at workable in microelectronics.