The Effect of the Thickness of α-Fe_2O_3 Nanocrystalline Thin Film on the Photocurrent Response

The photoelectrochemistry of α Fe 2O 3 nanocrystalline thin films with different thickness in KCl solution was studied. It is found that the photocurrent response was decreased with the film thinkness. The decrease of photocurrent responses of thicker films is explained in terms of the electric resistance effect and recombination effect. For thinner α Fe 2O 3 film (50 μm) no difference was found for the photocurrent response under frontwall (FW) and backwall (BW) illuminations, while for thicker α Fe 2O 3 film (100 μm) the photocurrent response was larger under BW illumination than that under FW illumination.