Integrated Electromagnetic Device with On‐Off Heterointerface for Intelligent Switching Between Wave‐Absorption and Wave‐Transmission

Abstract Intelligent electromagnetic wave absorbers (IEAs) are in high demand due to their dynamic electromagnetic parameters that can adapt to the complex and volatile application environments of the current 5G era. Despite of this, there is currently a lack of research on the convertible electromagnetic wave (EMW) absorption mode (switching between wave‐absorption and wave‐transmission) and their integrated design with external physical stimulations, so that the electromagnetic device will realize intelligent switching in any conditions. In this work, a V 2 C‐VO 2 (M) heterostructure that exhibits a reversible metal–insulator transition at the temperature of 62 °C is fabricated via oxidation of MXene. The heterostructures demonstrate near wave‐transmission characteristics at 25 °C while wave‐absorption behavior with wide effective absorption bandwidth (4.04 GHz) at 70 °C. VO 2 (M) exhibits stronger intrinsic conductivity after phase transition, and the “on‐off” heterostructure between V 2 C and VO 2 lead to poor/strong local conductive network and interfacial polarization in 25/70 °C, thus creating “quantized” dielectric loss. Furthermore, a multilayered electromagnetic functional device is developed to facilitate the absorber's phase transition temperature at a voltage of 17.5 V. This work presents promising opportunities of the V 2 C‐VO 2 (M) heterostructure for various applications, including radar stealth, portable stealth suits, signal regulation, and deicing.