Quantifying work function using kelvin probe systems

Quantifying the work function of materials is a major component of research dedicated to developing in vacuo electrical devices with high current density at low operating temperatures. These devices are regularly composites of more than one material and understanding the roles that the individual components play in determining the overall work function is at the frontier of this research [1]. The work function characterization technique outlined here is analysis using a Kelvin Probe System, which yields the opportunity to quantify a material's work function through measuring contact potential difference (CPD) or through surface photovoltage spectroscopy (SPS). In this paper, these separate techniques are outlined and experimental data is given for W and Ba, two elements of interest in device development.