Addition of Cs+ ions to electrolytes utilized with n-type cadmium chalcogenide photoanodes has previously been reported to have major effects on the stability and in some cases the electrochemical output parameters of such cells. The observed behavior has been attributed both to chemical effects occurring in the electrolyte and to semiconductor surface modification based on the adsorption of Cs+ ions. The present study evaluates the effects of Cs+ on n-CdX/ferri-ferrocyanide (X= S, Se) photo- electrochemical cells. Two effects are observed: the intercalation of Cs+ into [CdFe(CN)6] 2- 1- overlayers which are intrinsic to the semiconductor surface, and the specific chemisorption of Cs+ onto CdSe surfaces. The former effect is found to reorganize the overlayer microstructure allowing for enhanced interfacial charge transport, while the latter process leads to unfavorable heterogeneous charge-transfer kinetics.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Chemical Engineering(all)