RECOMBINATION AND CHARGE-TRANSFER AT THE ILLUMINATED N-CDTE ELECTROLYTE INTERFACE - SIMPLIFIED KINETIC-MODEL

In relation to the growing interest in photo-electrochemical solar cells, many efforts have been made, during recent years, to describe the behavior of the illuminated semiconductor/electrolyte junction. The experimental behavior of the illuminated n-cadmium telluride/aqueous electrolyte interface is presented with a precise analysis of the electrical impedance in an acidic medium. Band edge shifts and the photocurrent onset position are observed to depend strongly on the pH value. They are interpreted by considering mainly the kinetics of the different reactions at the interface. An analytical model is then developed allowing the fitting of both current-voltage and impedance curves. The equivalent circuit derived from the model explains the origin and the variation of the recombination resistance observed experimentally.