Field effect nanogenerator operated by sliding gates

Abstract

Controlling the motion of charge carriers in semiconductor materials is a fundamental strategy for achieving many functional devices, which is typically achieved by applying an external voltage source. Herein, using the electrostatic potential generated by a triboelectric material taken as a sliding “gate”, a functional current is generated across a semiconductor channel when the gate is moving in parallel to the dielectric surface. Systematic studies verify that the motion of the electrified “gate” induces the regional and dynamical doping of the semiconductor channel, thereby driving the carrier transport without applying an external voltage. This sliding-gated generator achieves mechanoelectric energy conversion based on the coupled triboelectrification effect and electrostatic field effect and is therefore termed as a field effect nanogenerator (FENG). It can output electrical currents with a waveform that follows well with the sliding speed of the gate, which makes it different from conventional induction-based triboelectric nanogenerators with instantaneous outputs. Moreover, it can yield 3 times higher averaged power density than that of a sliding-mode triboelectric nanogenerator. In addition, a rotary FENG is designed for practically viable direct-current generation. This work presents an undiscovered strategy for carrier manipulation in semiconductors, demonstrating a promising mechanoelectric energy conversion mechanism and a practical self-powered device.