Tribovoltaic performance of the Schottky contact between metal and PZT ceramic

Abstract

The sliding contact between a metal or semiconductor with another semiconductor can lead to a new charge generation mechanism known as the tribovoltaic effect. This effect has several advantage over the more common triboelectric effect, such as a higher rate of charge transfer and the ability to produce a direct current (DC) output directly via the junction interface. During operation, the junction interface produces a built-in electric field. In this study, we investigate the tribovoltaic effect on sliding between copper and unpoled lead zirconate titanate (PZT) ceramic. It was found that the contact between the metal and semiconducting oxide ceramic leads to the Schottky junction effect, which can effectively drive frictionally excited charges to an external load. By increasing the applied stress to PZT, we observed different current-voltage characteristic curves. The proposed electronic band behavior determines the electrical output direction in the tribovoltaic nanogenerator (TVNG). This direction depends on the built-in electric fields formed at the junction. The performance of the TVNG was tested in both series and parallel connections, observing clearly improved electrical outputs for both. The proposed TVNG can efficiently power small electronic devices, such as LEDs, and charge capacitors in a short period of time. This work expands the understanding of unconventional transport mechanisms through the Schottky contact of PZT and metal, and provides fundamental knowledge for the future development of tribovoltaic devices. © 2024 Elsevier Ltd and Techna Group S.r.l.