Metal‐Gallium Arsenide Based Tribovoltaic Nanogenerators and its Application for High‐Precision Self‐Powered Displacement Sensors

Triboelectric nanogenerators (TENGs) based on metal and semiconductors have attracted great interest due to their direct-current (DC) output characteristics and better integration with an integrated circuit. In order to increase the DC output performance, a new type of metal-gallium arsenide tribovoltaic nanogenerator (MG-TVNG) is developed. The DC output characteristics of gallium arsenide-based and silicon-based devices are compared by a conductive atomic force microscope (CAFM), and the output of gallium arsenide-based devices is dozens of times higher than that of silicon-based devices, which verifies the influence of physical factors such as carrier mobility and surface state density on the tribovoltaic effect. The current density of 28.3 A m(-2) can be obtained when using a single metal probe to slide on p-type gallium arsenide, outperforming previously reported silicon TVNGs. The effects of operating parameters such as sliding velocity and load pressure on the output of the MG-TVNG are further characterized. An MG-TVNG-based micro/nano grid displacement sensor is also successfully demonstrated and shows good potential in microscale displacement detecting.