The Kelvin probe is a non-contact, non-destructive vibrating capacitor device used to measure the work function (WF) of conducting materials or surface potential (SP) of semiconductor or insulating surfaces. This system from KP Technology offers a WF resolution of 1-3 meV. The high-resolution 3-axis translation stage allows performing 50 x 50 mm 2D scans. The Kelvin probe is set up inside a Faraday and light enclosure to prevent from unwanted electromagnetic interferences.
For semiconductor surfaces, both organic (Polymer) and inorganic (Si, Ge, CdS, etc), the Kelvin probe can measure changes in Fermi level, caused by illumination with white or monochromatic light, and resulting in energy band shifts. This technique is called Surface Photovoltage Spectroscopy (SPS). The SPS030 and SPS040 packages include a motorized monochromator with a wavelength range of 400 to 800 nm. They allow for variable intensity and variable frequency measurements as well as AC or DC photovoltage measurement options.