Nonadiabatic quantum dynamics of tribovoltaic effects at sliding metal-semiconductor interfaces

TL;DR

This paper develops a quantum mechanical model to explain how electric voltage is generated at sliding metal-semiconductor interfaces, highlighting the role of local temperature and bandgap in electron-hole pair creation and voltage generation.

Contribution

It introduces a two-band Anderson-Holstein model with surface hopping to quantitatively simulate tribovoltaic effects at sliding interfaces, linking temperature, bandgap, and voltage.

Findings

Higher local temperatures increase electron-hole generation.

Electric voltage exhibits a turnover as a function of bandgap.

The model aligns with experimental observations.

Abstract

Recent experiments observe electric current generation at a sliding metal-semiconductor interfaces. Here, we present a detailed theoretical study on how electric voltage is generated at such a sliding interface. Our study is based on a two-band Anderson-Holstein model, and we solve the coupled electron-phonon dynamics using a surface hopping method. We show that the high local temperature induced by mechanic motion at the interfaces could lead to electron-hole pair generation through electron-phonon couplings. We quantify the efficiency of electron-hole generation as well as electric voltage as a function of local temperatures and semiconductor bandgaps. We find that increasing the local temperatures can lead to higher electron-hole generations and electric voltage. Furthermore, we find that there is a turnover for the electric voltage as a function of the bandgap. Such an observation is in agreement with the experimental results. Our study offers a theoretical framework to understand tribovoltaic effects from a quantum mechanical point of view, and our approach can be used to quantitively simulate realistic sliding metal-semiconductor junctions.