An improved electrochemical cell for the characterization of silicon/electrolyte interfaces

Abstract

An electrochemical cell was made of a Teflon tube which was tightly pressed on the surface of a silicon wafer. The Teflon/silicon contact was tight enough to prevent any infiltration of solution, because it was observed that confined electrolyte was a source of irreproducibility. The device was enclosed within a black polyvinyl box which protected the sample against room light but allowed irradiation with a controlled light intensity. The cell was fed under argon pressure with a thoroughly degassed electrolyte, and the whole volume inside was maintained under argon atmosphere. This cell permitted very stable and reliable rest potential measurement and current–potential diagrams. The method proved useful in the study of the influence of light irradiation and of dissolved oxygen or metal ions trace impurities in the electrolyte.