Determination of electric potential difference using the Kelvin probe, i.e. vibrating capacitor technique, is one of the most sensitive measuring procedures in surface physics. Periodic modulation of distance between electrodes leads to changes in capacitance, thereby causing current to flow through the external circuit. The procedure of contactless, non-destructive determination of contact potential difference between an electrically conductive vibrating reference electrode and an electrically conductive sample is based on precise control measurement of Kelvin current flowing through a capacitor. The present research is devoted to creation of a new low-cost miniaturised measurement system to determine potential difference in real time and at high measurement resolution. Furthermore, using the electrode of a reference probe, the Kelvin method leads to both the indirect measurement of an electronic work function, or a contact potential of sample, and of a surface potential for insulator type samples.
In the article, the first part of the research, i.e., the basic principles and prerequisites for establishment of such a measurement system are considered.
evaluated by a Shimadzu X-ray diffractometer, model XD-D1 with CuK α radiation target, λ = 1.5418 Å, operated at 40 kV and 30 mA in a wide range of Bragg’s angles (2θ = 5° to 90°). Film morphology was studied using an atomic force microscope, AFM, Agilent type, AFM 5500, USA. AFM is a powerful tool to obtain high resolution maps of surface potential distribution on conducting and non-conducting samples. Contactpotentialdifference better than 0.1 mV and the lateral dimension (≤50 nm) were obtained for the samples under investigation. A conventional hot-probe experiment