Influence of organic material and sample parameters on the surface potential in Kelvin probe measurements

Abstract

Scanning Kelvin probe is a method for material surface studies. It is used to determine the work function of metals. In the case of organic semiconductors, the measured surface potential is considered to be the Fermi level of the material which has been shown in some cases. But in most papers, the surface potential dependence on the metal electrode or film thickness was observed. Material properties and their influence on the measured surface potential and its relation to the Fermi level previously have not been systematically studied. In this work, the surface potential was measured for different materials-metal, organic dielectric material, and organic semiconductors. In most of the cases, the obtained surface potential was dependent on the metal electrode work function. This dependence decreased with the increase in electrical conductivity of the material. Several materials were chosen for studies where sample thickness was varied. Results showed that for most of the studied semiconductors the sample thickness of around 1.5-2 µm was required to obtain surface potential values which do not depend on the electrode work function.

Spray‐Coated Inorganic Lead‐Free Double Perovskite Cs2AgBiBr6 Based Large‐Scale Triboelectric Nanogenerator for Enhanced Energy Harvesting

“…Concurrently, the ultimate trend of spin-coated and sprayed CABB TENG assembled with same polymer is identical as PTFE, suggesting that the characteristics of sprayed films' output are better than spin-coated one where surface properties like surface potential and roughness affect 𝜖 r [63] and W f . [64] Long-term ceaseless test in all inorganic lead-free double perovskite CABB TENG output characteristics is presented in Figure 5a. After >900 s of continuous experiment, both spin-coated and sprayed CABB TENG with a mechanical frequency of 0.25 Hz demonstrate superior stability without any voltage attenuation.…”

“…Concurrently, the ultimate trend of spin‐coated and sprayed CABB TENG assembled with same polymer is identical as PTFE, suggesting that the characteristics of sprayed films’ output are better than spin‐coated one where surface properties like surface potential and roughness affect ε r [ 63 ] and W f . [ 64 ]…”

Exploration of a micro multi-electrode technology applied in an air arc heater

“…Therefore, the work function difference between the LWF phase and copper plays an important role in determining the arc-attraction ability of the LWF phase. The work function difference is equal to the surface potential difference [28,35]. The surface potentials of the prepared alloys were measured by Kelvin probe force microscopy, which was operated in open air.…”