In₂O₃ Nanocrystals with a Tunable Size in the Range of 4−10 nm: One-Step Synthesis, Characterization, and Optical Properties

Nearly monodispersed indium oxide (In 2 O 3 ) nanocrystals with tunable sizes of <10 nm were prepared by a one-pot solvothermal route using indium oleate as the precursor. The nanocrystals were characterized by transmission electron microscopy (TEM), high-resolution TEM, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric techniques. A kinetically controlled hydrolysis of indium oleate based on the water deficiency in the system was attributed to the time-dependent crystal growth, in which a heterogeneous nucleation and growth of new In 2 O 3 onto the preformed nuclei were carried out. A weak quantum confinement effect of In 2 O 3 nanoparticles resulting from the small crystal size was observed in UV spectra, and three photoluminescence emission peaks occurring in the visible region were detected as well.