  We consider the factors that affect the photoactivity of silicon electrodes
for the water-splitting reaction using a self-consistent continuum solvation
(SCCS) model of the solid-liquid interface. This model allows us to calculate
the charge-voltage response, Schottky barriers, and surface stability of
different terminations while accounting for the interactions between the
charge-pinning centers at the surface and the depletion region of the
semiconductor. We predict that the most stable oxidized surface does not have a
favorable Schottky barrier, which further explains the low solar-to-hydrogen
performance of passivated silicon electrodes.
