Novel urchin-like In2S3 microspheres constructed with nanoflakes were synthesized via a single-source approach using indium diethyldithiocarbamate as precursor under hydrothermal conditions. In2O3 nanoparticles with the average diameter of 20 nm were obtained by calcining the as-synthesized In2S3 microspheres at 500 degrees C under ambient pressure. The samples were characterized by XRD, IR, TEM, and XPS. The optical properties of In2S3 micro-spheres and In2O3 nanoparticles were also investigated. UV-vis spectra indicate that there exists obvious blue shift compared with the In2S3 and In2O3 bulk materials. PL spectra demonstrate that the as-prepared In2S3 and In2O3 crystallites can emit at 355 and 380 nm, respectively. (c) 2005 Elsevier B.V. All rights reserved.