KP Technology APS04

Equipment: APS04 
Technique: Ambient Pressure Photoemission Spectroscopy System
Acquisition year: 2022
Responsible: Emmanuel Kymakis /   

Description: The APS04 system combines two different techniques: Ambient pressure Photoemission Spectroscopy (APS) (absolute work function Φ/IE/HOMO) and high-resolution Kelvin Probe KP. APS + KP allows both the Fermi-level and valance band maximum/HOMO level of semiconductors to be rapidly determined. The APS system allows total photoelectron yield to be measured as a function of a tuneable DUV source. A second tuneable Visible/IR source is used to perform DC and AC white light Surface Photovoltage (SPV), and Surface Photovoltage Spectroscopy (SPS) measurements allowing Eg to be determined. Finally using the scanning Kelvin probe (SKP) the sample work function and surface topography can be mapped up to 50 x 50 mm2.


  • Measurement Principle Photoelectric Effect: Energy Range 3.4 – 7 eV, Repeatability Precision 0.05 eV
  • Work Function resolution 1-3 mV (2mm), 5-8 meV (50 μm)
  • Maximum Sample Size 50 x 50 mm (2 x 2 inches
  • Automatic Measurement of surface potential, DC-SPV.
  • Relative Humidity Control Relative humidity chamber 25-80%
  • Relative Humidity Resolution 1%
  • Sample Temperature Control: RT-250oC