Electrostatic potential measurement at the Pt/TiO${}_2$ interface using electron holography

Abstract

The interface of Pt/TiO${}_2$ plays an essential role in device engineering and chemical reactions. Here, we report the electrostatic potential distribution of a Pt/TiO${}_2$ interface by electron holography. The decrease of the electrostatic potential exists at TiO${}_2$ in the vicinity of the interface, indicating the presence of negative charge due to electron transfer from TiO${}_2$ and Pt. The decrease of the electrostatic potential can be understood in the difference in work functions between Pt and TiO${}_2$. This study reveals the interplay between Pt and TiO${}_2$ and the usefulness of electron holography for probing the potential in nanoscale interfaces.