Synthesis and photoluminescence of In_2O_3 nanocrystals and submicron crystals from InCl_3·4H_2O and thiourea

摘要

Two routes have been proposed for the synthesis of In_2O_3 powders from InCl_3·4H_2O and thiourea. One route involved a two-step procedure (that is, firstly, In_2S_3 clusters constructed with mainly nanoflakes were synthesized by heating the mixture of InCl_3·4H_2O and thiourea in air from room temperature to 200 ℃, coupled with a subsequent washing treatment; secondly, In_2O_3 was obtained by calcining the In_2S_3 clusters in air at 600 ℃ for 6 h), and the other route was a one-step procedure (that is, In_2O_3 was synthesized directly by calcining the mixture of InCl_3·4H_2O and thiourea in air at 600 ℃ for 6 h). The resultant products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electronic microscope and room temperature photoluminescence (RT-PL) spectra. It was observed that the In_2O_3 nanocrystals obtained via the two-step procedure exhibited PL peaks at about 453 and 471 nm, corresponding to the defeat-related emission; while the In_2O_3 submicron polyhedral crystals obtained via the one-step procedure and In_2O_3 pyramids obtained by calcining the only InCl_3·4H_2O in air at 600 ℃ for 6 h displayed a PL band centered at around 338 nm, corresponding to the band edge emission.