Optoelectronic properties of β-Fe2O3 hollow nanoparticles

The effect of hollow structure on the optoelectronic properties of beta-Fe2O3 hollow nanoparticles (HNPs) was determined. Spectrophotometry showed that the optical transmittance of the beta-Fe2O3 HNPs was less than 40% in the visible-light region. This opaqueness was suggested to be an optical characteristic, commonly found in the authors' previous studies of TiO2 and delta-Al2O3 HNPs. In addition, beta-Fe2O3 HNPs had a band gap (1.86 eV) between amorphous (1.73 eV) and polycrystalline (1.97 eV) beta-Fe2O3 thin films, which was a 5-7 nm thick shell that embraced an intermediate volume of the crystal phase, in-between the two thin films. (C) 2008 Elsevier B.V. All rights reserved.