Wear-Resisting and Stable 4H-SiC/Cu-Based Tribovoltaic Nanogenerators for Self-Powered Sensing in a Harsh Environment.

Tribovoltaic nanogenerators (TVNGs) are an emerging class of devices for high-entropy energy conversion and mechanical sensing that benefit from their outstanding real-time direct current output characteristics. Here, a self-powered TVNG was fabricated using a small-area 4H-SiC semiconductor wafer and a large-area copper foil. Thus, the cost of materials remains low compared to devices employing large-scale semiconductors. The 4H-SiC/metal-TVNGs (SM-TVNGs) presented here are sensitive to vertical force and sliding velocity, making them appropriate for mechanical sensing. Notably, owing to the modulated bindingtons and surface states, these SM-TVNGs performed well in a harsh environment, namely, in high-temperature and high-humidity conditions. In addition, the SM-TVNGs exhibited an excellent wear-resisting property. On these bases, we designed a self-powered and real-time monitoring device able to estimate the number of staff present in various areas of a deep mining site, a high-temperature and high-humidity environment. This work not only discloses basic physics behind the tribovoltaic effect but also sheds light on possible applications of SM-TVNGs for wear-resisting and stable mechanical sensors in harsh environments.