Abstract:
Impedance measurements were used to evaluate the relative band edge positions of single crystal
p-CuInSej electrodes in aqueous 0.1M IQS04
solution by measuring die extrapolated flat-band
potentials, Vf t . We find that Vf t
can be shifted by oxidation and reduction of the electrode surface
and this observation was verified by chopped light current-potentialmeasurements. The surface state
density distribution responsible for this shift was evaluated and found that it islocated at 0.43 eV
above the valence band with a peak density of 3x101 4
eV'1
cm' 2
and it could be removed by
electrochemical reduction