Millimeter- and Terahertz-wave stochastic sensors based on reversible insulator-to-metal transition in vanadium dioxide

Abstract

Sensitivity to low-energy photons in phase change materials enables the development of efficient millimeter-wave (mm-wave) and terahertz (THz) detectors. Here, we present the concept of uncooled mm-wave detection based on the sensitivity of IMT threshold voltage to the incident wave by exploiting the characteristics of reversible insulator-to-metal transition (IMT) in Vanadium dioxide (VO2) thin film devices. The detection concept is demonstrated through actuation of biased VO2 2-terminal switches encapsulated in a pair of coupled antennas on a Si/SiO2 substrate. We also study the behavior of VO2 switches interrupting coplanar waveguide (CPW)s. Ultimately, we propose an electromagnetic wave-sensitive voltage-controlled spike generator based on the VO2 switches in an astable circuit. The fabricated sensors show record figs. of merit, such as responsivities of around 66.3 kHz/mW with a low noise equivalent power (NEP) of 20 nW at room temperature, for a footprint of 2.5×10−5 mm2, which can be easily scaled. This solution gives 3 times better responsivity with only 1/10 footprint of the state of the art. However, the footprint is capable of being scaled down to few hundreds of nanometers. The responsivity in static measurements is 76 kV/W in the same circumstances. Based on experimental statistical data measured on robust fabricated devices, we investigate and report stochastic behavior and noise limits of VO2-based spiking sensors that are expected to form a new class of energy efficient transducers. The results highlight the capability of VO2 phase transition to serve for building electromagnetic power sensors, that can be triggered by low energy photons.

Review of the VO2 smart material applications with emphasis on its use for spacecraft thermal control

“…3.17 Vanadium dioxide for sensors Qaderi et al (2021) proposed the VO 2 as sensor for the Millimeter-and Terahertz-wave stochastic sensors, by monitoring and characterizing the VO2 MIT as well as its slope, considering the heating Joule effect of the waves along with the electromagnetic effect.…”