Monolayer Oxidized‐MXene Piezo‐Resonators with Single Resonant Peak by Interior Schottky Effect

Nanoelectromechanical systems (NEMS) of 2D nanomaterials are potent exploration devices for high‐sensitive mechanical coupling, mass testing, and biosensing. Nevertheless, the internal interference from the multiple resonant states easily causes the deviation and overlap of the target signal. Here, an oxidized‐MXene resonant system performs the unique response peak at the fundamental frequency f0,1 of 3.37 ± 0.04 MHz within the ultrawide frequency up to 400 MHz, due to the ferroelectric‐conductive structure. This unique resonant peak can effectively avoid the dispute of indistinguishable vibratal states. The resonator exhibits advanced performances with a large dynamic range of 70.41 ± 0.15 dB and low thermomechanical motion spectral density of 669 fmHz$669\;\frac{{{\rm{fm}}}}{{\sqrt {{\rm{Hz}}} }}$ . The molecular sensing mechanisms of the oxidized‐MXene system are systematically studied to achieve repeatable detection with high mass resolution (low to 8.00 ± 0.01 × 10‐19 g). These consequences can afford potential guidelines for the NEMS devices in terms of the credible and legible sensors for ultra‐accurate and interference‐free measurements.