ABSTRACT
Adding halides to the electrolyte, the shift of bands under illumina
tion and thereby the photocurrent onset potential decreased in accordance
with the change in the redoxpotential of the halide couple used. The results
can only be understood in terms of Fermi level pinning by the redox couple
about 0.5 to 0.8 V below the Fermi level of the semiconductor. This is
Ktthne (1987). This means, however, that hole transfer is always connected
with an energy loss of more than 0.5 eV. In addition the question arises,
whether the semiconductor/metal Schottky junction which acts as a pure solid
state device, should really be immersed directly into the electrolyte.
