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

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.