Kelvin probe techniques are used to measure the work functions of materials. They have been successfully applied in surface science for decades, usually under UHV conditions. It is employed to study the adsorption of molecule surfaces or reconstruction processes of single-crystal surfaces. Both of which cause a change in the surface or dipole potential.
What is the Kelvin probe technique?
The Kelvin Probe technique is a
non-contact, non-destructive method that measures the change in the contact
potential difference (CPD) between the sample and the electrode using a
vibrating reference electrode.
The work
function difference between the tip and sample is produced using the
conventional Kelvin probe. Lord
Kelvin, a renowned Scottish scientist, proposed the Kelvin method in 1861.
Typically, the tip is calibrated against a reference surface, such as gold.
However, KP Technology is the only company that offers absolute Kelvin probes.
To generate absolute work function values, this combines the Einstein Photoelectric
Effect with the Kelvin technique (in eV).
Specifications of Kelvin probe
Because the topmost 1 - 3 layers of atoms or molecules define the WF of a surface, the Kelvin probe is one of the most sensitive surface analysis techniques available. KP Technology systems have an extremely high wf resolution of 1 - 3 meV. This is currently the highest achieved by any commercial device.
It does not make
physical contact with the surface.
Instead, an electrical connection is made to another part of the sample
or sample holder.
A head unit with
a voice coil driving system and an inbuilt amplifier suspended above a sample
is the physical form of a Kelvin Probe.
The sample and
the vibrating tip combine to create a capacitor with a perfect, or
parallel-plate shape. Electric charge is pushed around the external detecting
circuit as the tip vibrates. Both the potential across the capacitor and the
capacitor spacing can be determined to very high resolution. It can be done by
carefully controlling the tip potential and automatically capturing and
analyzing the resulting waveform.
Kelvin probes for Semiconductor surfaces
The Kelvin probe is the only method for
accurately measuring the Fermi level on semiconductor surfaces, including
organic (polymer) and inorganic (Si, Ge, CdS, etc.) semiconductor surfaces.
White or monochromatic light illumination alters the Fermi level, causing
energy band shifts that can be utilized to describe the interface and bulk
defect states. These processes are known as Surface Photovoltage (SPV) and
Surface Photovoltage Spectroscopy (SPS).
KP Technology can provide our systems with the necessary software and
add-ons.
Equip-Test- Ultimate destination for all interface
solutions
Equip-Test is a
worldwide manufacturer of test probes and fixture kits for a variety of
applications. Our primary product line consists of test probes, test fixture
kits, customized ICT, functional test fixtures, and integrated ICT with
function testing capabilities. We make significant investments in research and
development, internal laboratories, and high-tech manufacturing plants. If you
have any concerns, our knowledgeable staff will be happy to assist you. Visit
our official website today if you are looking for interface solutions or probe
test tools. You can also get a quote by calling +36-29/550-940.
