Conductivity and Surface Resistivity
An appropriate way to measure the conductivity of Clevios™ is to deposit the material as a thin homogeneous layer on a flat substrate by using deposition techniques such as spin-coating or doctor-blading. The thickness of the layers should be 50 - 500 nm.
The layer thickness can be determined by scratching the film off the substrate with a razor blade and scanning the stylus of a mechanical or optical profile meter across the scratch. Sheet resistance can then be measured with conventional four-point probes.
Alternatively, the sheet resistance can be determined with a multimeter by measuring the impedance between parallel contacts. The contacts can be deposited onto the Clevios™ layer for example with silver paint or by evaporating metals through a shadow mask. In case of simple two-point measurements the resistance of lead-in wires and contacts have to be negligible.
The resistance of high Ohmic Clevios™ P OLED-Types (Clevios™ P AI 4083 and Clevios™ P CH 8000) have to be measured in dry atmosphere, i.e. in a vacuum chamber or in a glove box filled with N2 or Ar to avoid the influence of humidity. In case of Clevios™ P CH 8000 the width between metallic contacts should be small relative to its length (b << a), otherwise the resistance will become too large to be measured properly.