Effect of sintering temperature on structural and optical properties of indium(III) oxide nanoparticles prepared with Triton X-100 by hydrothermal method

Indium(III) hydroxide (In(OH)(3)) powders prepared via Triton X-100 mediated hydrothermal method was sintered at different temperatures (400, 500 and 600 degrees C) to yield indium(III) oxide nanoparticles (In2O3 NPs). Thermal studies of In(OH)(3) confirmed complete conversion to In2O3 around 400 degrees C. Powder X-ray diffraction (XRD) pattern of sintered In2O3 nanoparticles revealed the formation of phase pure cubic In2O3. The crystallite size of In2O3 NPs was increased from 12 to 26 nm upon increasing the sintering temperature from 400 degrees C to 600 degrees C, while the percentage crystallinity was increased up to 90% after sintering at 600 degrees C. A red shift in the band gap energy was observed with increasing sintering temperature due to the larger size of sintered In2O3 NPs. Room temperature photoluminescence spectra of the indium oxide nanoparticles showed both near band and excitonic emission of In2O3 due to oxygen vacancies. (C) 2014 Published by Elsevier B.V.