Quantitative measurement of the surface charge density

TL;DR

This paper introduces a novel method for quantifying surface charge density on dielectric materials by measuring electrostatic interactions at large tip-sample distances, calibrated with a pyroelectric sample.

Contribution

It presents a new measurement technique for surface charge density that operates at large distances and uses temperature-controlled calibration with pyroelectric materials.

Findings

Successfully measured surface charge density on lithium niobate

Calibrated the method using pyroelectric samples

Demonstrated the technique under ambient conditions

Abstract

We present a method of measuring the charge density on dielectric surfaces. Similar to electrostatic force microscopy we record the electrostatic interaction between the probe and the sample surface, but at large tip-sample distances. For calibration we use a pyroelectric sample which allows us to alter the surface charge density by a known amount via a controlled temperature change. For proof of principle we determined the surface charge density under ambient conditions of ferroelectric lithium niobate.