hollow nanostructure; nanomaterials; beta-Fe2O3; band gap energy; surfaces; light reflection; BAND-GAP ENERGIES; THIN-FILMS; OPTICAL-PROPERTIES; SPRAY-PYROLYSIS; GAMMA-FE2O3; TIO2
ELSEVIER SCIENCE BV
MATERIALS LETTERS, v. 62, No. 17-18, Page. 2664-2666
The effect of hollow structure on the optoelectronic properties of β-Fe2O3 hollow nanoparticles (HNPs) was determined. Spectrophotometry showed that the optical transmittance of the β-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 δ-Al2O3 HNPs. In addition, β-Fe2O3 HNPs had a band gap (1.86 eV) between amorphous (1.73 eV) and polycrystalline (1.97 eV) β-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.