Charge storage in SnO_2 nanoparticles: A method and mechanism for charge writing/erasing

摘要

In this work, we present and explain evidence of a charge confinement phenomena exhibited by SnO_2 nanoparticles. By applying a voltage pulse from the scanning tunneling microscope (STM) tip or momentarily increasing the gap voltage, charged features can be written on the surface. The voltage dependence of the apparent height of the features, and current imaging tunneling spectroscopy experiments, supports the charge confinement theory put forward. This is substantiated by a numerical model illustrating how charge is confined in individual nanoparticles, and is used to explain the observations of STM experiments.