An electrochemical deposition route for obtaining α- Fe ₂O₃ thin films: II. EQCM study and semiconductor properties

The electrochemical formation of hematite (α- Fe2 O3) precursor thin films (oxyhydroxide iron compounds), onto gold substrates in an aqueous solution of Fe(III)+KF+ H2 O2 was investigated in situ using an electrochemical quartz crystal microbalance (EQCM) and voltammetric techniques. Nanostructured α- Fe2 O3 obtained after annealing of oxyhydroxide iron compounds thin films have been prepared onto SnO2 F covered glass substrates through a potential cycling procedure in this electrolytic bath. Photoelectrochemical measurements, carried out in 0.1 M NaOH+0.05 M KI electrolyte at pH 13, show an n-type behavior, a flatband potential of -1.08 V vs saturated mercury/mercury sulfate reference electrode, and an apparent donor density of 1.26× 1019 cm-3 at 1 kHz.