Modeling of single-electron tunneling networks for supersensitive sensors at room temperature

Abstract

Due to their unique properties of ultralow power dissipation and extremely high density, single-electron devices represent the best option for highly sensitive sensors. Despite their excellent performance in capturing subtle electrical signals at cryogenic temperatures, the signal detectability at room temperature or higher is substantially degraded by thermal noise. To reduce such interference from thermal noise at room temperature, the physical dimensions of single-electron devices are conventionally scaled down to below 10 nm, but this leads to great challenges in device fabrication processes. The challenge of retaining superior signal detectability of single-electron devices at room temperature without aggressive scaling is addressed herein. It is proposed that the effects of capacitive and resistive signal coupling between adjacent single-electron devices can be exploited to enhance the signal-to-noise ratio of sensor outputs. A series of efficient coupled networks that shift the peak signal detectability from cryogenic to room temperature are studied. The impacts of the network topology, coupling strength, and bias voltage are investigated. The simulation results reveal that, for given device dimensions, the proposed coupled device network improves the room-temperature signal detectability by 13.2 dB (i.e., an enhancement of 200%) over the uncoupled device array. Moreover, at room temperature, the signal-to-noise ratio of the proposed nonscaled coupled device network is much better than that of aggressively scaled device arrays. These results confirm that efficient coupled networks enable the operation of supersensitive single-electron device sensors at room temperature.