Improved photoelectrochemical response of haematite by high energy Ag9+ ions irradiation

Haematite (alpha-Fe2O3) thin films deposited on a conducting glass substrate were irradiated with 120MeV Ag9+ ions with increasing ion fluences. Their structural evolution was determined by x-ray diffraction and Raman spectroscopy. The irradiation of the samples of alpha-Fe2O3 was found to be effective in improving its photoelectrochemical response. The film irradiated at a fluence of 1 x 10(13) ions cm(-2) showed a significantly higher photocurrent density than the unirradiated alpha-Fe2O3. This effect is correlated with the transition from the alpha-Fe2O3 to the Fe3O4 phase and the reduction in grain size that were observed on irradiation with Ag9+ ions. The measured flatband potential and donor density of the sample were also maximum at a fluence of 1 x 10(13) ions cm(-2).