Influence of dissolved oxygen on intensity modulated photocurrent spectroscopy (IMPS) at a silicon-hydrofluoric acid interface

The kinetic parameters of the cathodic reaction in a silicon-hydrofluoric a cid system were measured using intensity modulated photocurrent spectroscop y (IMPS). The values and the potential dependences of the measured paramete rs were found to depend upon the concentration of dissolved oxygen. This is one of the reasons why photoelectrochemical measurements in this system ha ve sometimes given poorly reproducible results. The effects of the presence of dissolved oxygen are discussed by considering the surface states and th e relative energy levels of redox potentials in solution. (C) 2000 Elsevier Science Ltd. All rights reserved.