LIV. Effect of Redox Couple, Doping level, and Metal Type on the Electrochemical and Photoelectrochemical Behavior of Silicide-Coated n-Type Silicon Photoelectrodes

The surface potentials of silicide-coated n-type silicon photoelectrodes as functions of the potential of solution redox couples and the bias potential show that the Fermi level of these photoelectrodes is strongly pinned at the silicide/Si interface. The built-in potential barrier is consistent with the constancy in the photovoltage observed in solutions containing various reversible couples with redox potentials spanning a range larger than the bandgap of silicon. The performance of these photoelectrodes depends strongly on the metal, the charge transfer kinetics at the silicide/solution interface, and the doping density of silicon substrate.