Photoelectrochemical properties of semiconductor diamond

The photoelectrochemical behaviour of an electrode made of synthetic diamond has been studied for the first time. The photocurrent, differential capacity and dark current vs. potential curves have been measured on semiconductor diamond polycrystalline films on a tungsten substrate in contact with aqueous electrolyte solutions. The photoelectrochemical behaviour of diamond on the whole is described by means of a model of photogeneration and separation of charges in the depletion layer in the semiconductor. The flat-band potential has been measured with reference to surface pretreatment and solution composition. The purely surface effects have been shown to play an important role in the electrochemical behaviour of semiconductor diamond.