Controlled growth of hematite (α-Fe2O3) nanorod array on fluorine doped tin oxide: Synthesis and photoelectrochemical properties

Hematite nanorods were grown on fluorine doped tin oxide (FTO) substrates by hydrothermal means utilizing urea as a pH regulating agent. XRD for nanorods revealed pure hematite phase after annealing at 500 degrees C for 30 min with preferential orientation in the [110] direction. Electrochemical impedance spectroscopy was carried out to investigate the electrical properties. Using Mott-Schottky analysis, charge carrier density was estimated to be 5.62 x 10(19) cm(-3) in the hematite nanorod array. Among the nanostructures, the n-type hematite nanorod array showed the best conversion efficiency among the samples studied in a two electrode photoelectrochemical cell. Photocurrent measurements versus light intensity were performed to investigate the device performance and the limiting factors to the performance were attributed to the short diffusion length of minority charge carriers. (C) 2011 Elsevier B.V. All rights reserved.