Abstract
The additional capacitance, observed under illumination of the 
electrode in aqueous electrolyte, was measured as a function of the electrode potential, the measuring frequency, and the light intensity. Simple relationships were found between the peak maximum, the frequency, and the light intensity, and interpreted on the basis of a model in which electron hole recombination through surface states was assumed. The information concerning the surface‐state characteristics, obtainable from such measurements, is discussed.