Tribovoltaic Nanogenerators Based on MXene-Silicon Heterojunctions for Highly Stable Self-Powered Speed, Displacement, Tension, Oscillation Angle, and Vibration Sensors

Tribovoltaic nanogenerators (TVNGs), an emerging high-entropy energy harvesting technique, present great features such as low matching resistance, high current density, and continuous output performance. Here, an MXene layer and a semiconducting silicon wafer are assembled into a tribovoltaic nanogenerator (named MS-TVNG). The output peak current of the MS-TVNG reaches up to 22 mu A for a P-type (0.1-0.5 omega cm) silicon wafer under a normal force of 4.56 N and a sliding speed of 2 m s(-1). Owing to the unique metal characteristics of the MXene layer, the performance is superior to those previously reported TVNGs using traditional metals. The layered structure of MXene endows the real-time MS-TVNG with outstanding wear-resistance and stable output properties. The performance of the MS-TVNG can be tuned by the doping type and concentration of the silicon wafer, as well as by the pressure and the relative sliding speed between two friction surfaces. The MS-TVNG has proven to be a solid foundation for high-performance self-powered speed sensors and has excellent potentials for applications in displacement, tension, oscillation angle, and vibration detection.

Automated summary

Tribovoltaic nanogenerators (TVNGs) are a new energy harvesting technique with great features. The MS-TVNG, assembled with an MXene layer and a semiconducting silicon wafer, provides high peak current and has wear-resistance and stable output properties.