A novel double-layer graphene-MXene film and its applications

In the operational amplifier circuits, the precise control of output voltage with ultra-high precision is often necessary. To achieve high accuracy and adjustable output voltage, an innovative approach combining a double-layer graphene-MXene film with a conventional operational amplifier (op-amp) circuit is proposed for the first time. In this work, double-layer graphene-MXene films were prepared using a simple mixed solution coating technique. By mixing the Ti3C2Tx dispersion (MXene) with a graphene oxide (GO) aqueous solution at a volume ratio of 1:10, the film exhibits a high resistance value. The resistance value decreases significantly with an increase in pressure. The microstructure and morphology are characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The graphene-MXene film has a nanocomposite structure in which MXene replaces the carbon atoms in the graphene in an amorphous form, ensuring doping stability. The high defect density and thickness of the film make it have high resistance characteristics. The double-layer graphene-MXene film is applied in the common emitter amplification circuit and the subtraction circuit, respectively. In the common emission amplification circuit, the gain can vary between 1.30 and 1.64. In the subtraction circuit, the output voltage can vary between 2.29 V and 2.43 V with good linearity. Additionally, the response time and recovery time of this film are both less than 40 ms. The hysteresis error and repeatability error are both less than 0.3%. Therefore, the double-layer graphene-MXene films have a wide prospect in amplification circuits and subtraction circuits.