Triboelectric Junction: A Model for Dynamic Metal-Semiconductor Contacts

TL;DR

This paper introduces the triboelectric junction model to analyze dynamic metal-semiconductor contacts, highlighting how triboelectric effects influence electric output through junction direction and strength.

Contribution

It proposes a new theoretical model for dynamic contacts, linking triboelectric effects to electron affinity and output characteristics, supported by experiments.

Findings

Junction direction determines output polarity

Junction strength influences output amplitude

Electron affinity correlates with standard electrode potential

Abstract

Static metal-semiconductor contacts are classified into Ohmic contacts and Schottky contacts. As for dynamic metal-semiconductor contacts, the in-depth mechanism remains to be studied. We here define a "triboelectric junction" model for analyzing dynamic metal-semiconductor contacts, where a space charge region induced by the triboelectric effect dominates the electron-hole separation process. Through theoretical analysis and experiments, we conclude that the triboelectric junction affects the electric output in two aspects: 1) the junction direction determines the output polarity; 2) the junction strength determines the output amplitude. The junction direction and junction strength are both related to the electron-affinity difference between the contact metal and semiconductor. We find that the standard electrode potential in electrochemistry best describes the electron affinity of a dynamic metal-semiconductor contact.