FLAT-BAND VARIATION OF N-CADMIUM CHALCOGENIDES IN AQUEOUS CYANIDE

Flatband potential, V-fb, measurements of n-CdSe in alkaline ferrocyan ide electrolytes substantiate trends observed for photoelectrochemical open circuit voltage, V-oc, with dissolved cyanide. Similar trends co mprising a negative shift of V-fb and an increase in V-oc with increas ing concentration of cyanide are also observed for an n-CdTe alkaline ferrocyanide photoelectrochemical cell, PEC. Modification of an alkali ne ferro/ferricyanide electrolyte with KCN, in an n-CdSe or n-CdTe PEC , stabilizes the photocurrent, and increases the V-oc by several hundr ed millivolts. In the approach to the high cyanide concentration limit , V-fb for both n-CdSe and n-CdTe in alkaline ferrocyanide approaches a single limiting value of -1.2 V vs ferro/ferricyanide.