LIGAND, CATION AND SPECIATION EFFECTS ON N-CDSE ([KFE(CN)6](3-/2-)) PHOTOELECTROCHEMISTRY/

Electrolyte modification is shown to have a substantial effect on the understanding and optimization of n-CdSe/ferricyanide photoelectrochem ical solar cells. A series of pentacyanoferrate(II) complexes, [Fe(CN) 5L]3- aqueous are prepared (L = CN-, NH3, (CH3)2SO, H2O, NO+, NO2- and Fe(CN)53-), and their substantial variation in photoelectrochemical a ctivities at n-CdSe are correlated to their spectral and electrochemic al properties. Investigation into ferro/ferricyanide speciation showed that in the alkaline pH region where ferrocyanides are most photoelec troactive, monocation ferrocyanide and ferricyanide species dominate, MFe(CN)63-/2-. These cation derivatives (M = Mg2+, Ca2+, Li+, Na+, K+, Cs+, NH4+) are varied, and the potassium derivative was shown to resu lt in both high photopotentials and facile kinetics.