Ag/SeO₂/C Avalanche Type Resonant Tunneling Schottky Barriers

Abstract

Herein, the design and characterization of Ag/SeO₂/C avalanche type resonant tunneling devices are reported. Thin pellets of SeO₂ nano-powders pressed under hydraulic pressure of 1.0 MPa which is used as the active material are characterized. They showed tetragonal structure refereeing to space group of $P_{4_{2}mbc}$ and lattice parameters of $a=b=$7.866 $Å$ and $c=$5.336 $Å$. The current-voltage characteristic curves have shown that SeO₂ can perform as active media to produce resonant tunneling diodes when forward biased and as avalanche type diode when reverse biased. The peak to valley current ratios of these diodes reached 18.3. In addition, the impedance spectroscopy measurements have shown that the device works in the low impedance mode when operated in the microwave range of frequency near 1.50 GHz. Negative conductance effect is observed in that frequency domain. The features of the Ag/SeO₂/C nominate them for use as signal amplifiers and microwave oscillators.

Keywords:
Ag/SeO₂/C; tetragonal; microwave cavity; Esaki diodes; negative conductance