Sensitive THz Detection by Using Thermoresistive Effect in 2D Vanadium Dioxide

The thermoresistive effect is widely utilized in thermal sensors due to its simplicity in implementation and adaptability across a broad range of applications and spectral regions. However, the practical performance of thermoresistive materials is often hindered by hysteresis and nonlinearity in their temperature response, primarily due to metal-insulator transitions (MITs). Here, we show that single-crystalline, two-dimensional (2D) vanadium dioxide in its bronze phase (VO₂(B)) exhibits a hysteresis-free and highly linear thermoresistive response and can serve as an effective material for sensitive THz detection. The suppression of the metal-insulator transition (MIT) in 2D VO₂(B) is likely associated with the inhibition of vanadium-vanadium dimerization. Due to the suppressed MIT, 2D devices display an electrical conductivity (4.24 × 10^-3 Ω·cm) and a TCR (∼4.0%/K). In addition, a THz microbolometer based on 2D VO₂(B) exhibits a noise equivalent power of 722 pW/√Hz and a response time of ∼109 μs at room temperature. These results indicate the potential of 2D VO₂(B) for high-performance thermal detection applications.