Résumé
Understanding and modelling space charge at interfaces is fundamental as they are weak points of any system including layers with different electrical properties. The Thermal Pulse Method (TPM) may allow micronic resolutions near the thermally excited surface, especially if combined with surface temperature measurements. The present work aims to TPM fallbacks for directly measuring electric fields at interfaces of structures containing metallic, semiconducting, and insulating layers. 50 µm to 160 µm-thick polyethylene samples with and without coated semicon layers are used. They are provided with metallic electrodes deposited either directly on the dielectric or on the semicon layers, to act as bolometers for measuring the surface temperature. A dedicated measurement cell allows measurement, separation and amplification of both space charge and bolometric signals. The experimental set-up is detailed, and results obtained on the different type of samples are discussed. They show that the proposed setup and analysis of space charge and temperature responses measured simultaneously at the interface should allow direct measurement of the electric field at metal/insulator interfaces, and, surprisingly, also at metal/semicon interfaces.