Impedance Measurements at the N‐ and P‐Type GaP Single Crystal Electrode

Impedance measurements were made at the dark n‐ and p‐type single crystal electrodes in aqueous indifferent electrolyte solutions as a function of applied voltage and of frequency. The results allow the determination of the flatband potential and hence of the position of the Fermi level and the conduction and valence band edges at the electrode surface. The observed frequency dependence of the capacitance can be attributed to dipole relaxation phenomena in the space‐charge layer of the semiconductor electrode. The influence of preliminary etching on the frequency behavior is discussed.