CHEMICAL REACTIONS OF ELECTRONS AND HOLES AT ZNO/ELECTROLYTE-SOLUTION INTERFACE

Measurements of minority-carrier currents and space-charge capacitance at a semiconductor electrode are used to provide information regarding chemical reaction steps that occur at the electrode surface. In particular, it is shown how minority-carrier reactions on the zinc oxide surface may lead to current doubling. Use of this observation to study hole reactivity of reducing agents and to study free radical reactions is discussed, and preliminary observations are furnished. Reactions of majority carriers can be interpreted by capacitance measurements if the reactions are irreversible and first order in the concentration of carriers at the surface. The use of these capacitance measurements to study the electron reactivity of chemicals on the zinc oxide surface is discussed. © 1968.