The Kelvin Probe system allows to precisely measure the Contact Potential Difference (CPD) and to determine the Work Function of conducting and semiconducting material.
The non-contact technique of CPD measurements employs the Probe Tip-oscillating reference electrode made of a golden mesh. The examined sample serves as the second electrode in the circuit. The Work Function value is evaluated indirectly from the measured CPD of the sample referenced to the gold tip.
The Kelvin Probe system may be used in various types of studies of the material surfaces such as: corrosion and photocorrosion process, adsorption/desorption, surface charging, catalytic activity and others. Subsequent CPD measurements in adjustable time intervals allows to monitor the changes in real time. The measurement method is accurate for many types of samples: organic and inorganic semiconductors, solar cells, photoactive materials. During the measurement, the instrument is covered with the Faraday Cage to screen the ambient light and electromagnetic fields.
The Kelvin Probe set consists of:
The Kelvin Probe instrument is equipped with:
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The most important part of the Kelvin Probe instrument is the Probe Tip. The reference electrode is made of Au mesh of 2.5 mm diameter. It provides high signal to noise ratio, even from a distance of 0.5 mm above the sample. Thus, it does not matter if the examined sample surface is rough or polished. The tip oscillations are generated with an electromagnet.
The Probe Tip is the component fully designed and manufactured by Instytut Fotonowy Sp. z o.o.
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The standard Kelvin Probe Set includes two types of sample stands:
The entire instrument is covered with the Faraday Cage, shielding the setup from the ambient light and electromagentic fields.
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Scince measurements of the CPD is often sensitive to environmental factors like temperature, humidity, dust and chemical contaminants, Kelvin Probe may be placed inside the hermetic version of the Faraday Cage with the inert gas flow system.
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The Kelvin Probe is equipped with the Laser barrier system. System automatically detects the sample sub-
strate. Each time the probe approaches the sample being examined, an accurate distance between the sample surface and the Probe Tip is measured with 20 µm precision.
The sample may be illuminated during the measurements from the optical fiber situated above the Probe Tip. The Probe Tip lets the light through. The light at optical fiber input may be provided by the LED Revolver, Xenon Lamp combined with the Monochromator or any other type of the light source desired.
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Several types of liquid lightguides from Lumatec may be used to provide the sample illumination.
CPD values recorded for a Photodiode. The plot represents the response for a saw tooth type light intensity modulation.
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许多材料的特性取决于其表面。其中最重要的表面特性之一就是功函数。
开尔文探针系统可以高精度、高准确度地精确测量不同半导体和导电材料的功函数。
非接触式测量涉及振荡电容器，其中一个电极是试样，另一个是由金网格制成的振荡参比电极。因此，测量值以金的功函数（5.1 eV）为基准。在足够长的积分时间内，测量分辨率可达 0.1 meV。开尔文探针系统可用于各种表面研究，包括腐蚀、吸附/解吸、表面充电、催化活性等。
为方便起见，探头配备了激光指示器和数码显微镜。电动垂直定位系统可使参比电极与试样表面保持相同距离（精度为 10 微米）。可选配 X-Y 定位系统。该系统还配备了宽带光导，可与数字控制单色仪和高压氙弧灯连接。波长范围从 300 纳米到 1000 纳米，可用于连续或脉冲样品照明。这种配置可用于测量表面的功函数和电荷、表面光电电压光谱和其他光物理技术，光电电压分辨率优于 5 mV（积分时间长时为 0.1 mV）。整个系统安装在接地的法拉第笼中，以减少电噪声和杂散光的影响。这种表面光电电压光谱仪是研究光催化剂、有机和无机半导体、太阳能电池及其他光活性材料和器件的重要工具。借助这种开尔文探针/表面光电压光谱仪，还可以实时监测半导体的光腐蚀、光吸附和光催化反应。
该仪器由安装在坚固支架上的振荡金探针、Z 轴电动平台、电子控制单元和法拉第笼组成。
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探头尖端是完全由 Instytut Fotonowy 设计和制造的组件，它提供：
尖端振荡由电磁铁产生。
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由于仪器的不断发展，以下参数可能会发生变化
| Voltage range | -5 V .. 5 V |
| Voltage measurement nominal resolution | 0.15 mV |
| Measurement technology | 2-channel lock-in amplifier |
| Sample holder | translation stage X-Y, manual (default) or motorized |
| X-Y stage stroke | 15 mm x 15 mm |
| Tip type | Au mesh, dia. 2.5 mm |
| Tip Z positioning | motorized Z stage |
| Positioning with respect to a sample | light barrier |
| Tip Z positioning resolution | 10 µm |
| Spectral range for wave guides | 200 nm .. 2000 nm (depending on a waveguide) |
| Liquid waveguides selection (Lumatec) | |
| Auxiliary sensors | humidity and temperature |
| Internal Faraday cage illumination | white LED |
| X-Y positioning aid | laser sample placement indicator |
| PC connectivity | USB 2.0 |
| Size | 40 x 40 x 45 cm |
| Weight | 15 kg |
以下结果来自 Radecka 教授小组（波兰克拉科夫 AGH）。
抗蚀剂样品的表面光电压谱。光电压是根据脉冲照明与金栅参比电极的表面电位变化来测量的。
由于测量是在环境空气中进行的，因此仪器会记录空气湿度和温度。这两个参数可能会影响样品的功函数。
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