Situ growth of self-assembled and single In2O3 nanosheets on the surface of indium grains

Self-assembled In2O3 nanosheet networks and flowerlike nanoarchitectures, as well as single In2O3 nanosheets, have been grown in situ on indium substrate by heating indium grains at 900-950 degrees C under the flow of O-2 in the presence of a small quantity of P2O5. The as-synthesized In2O3 nanosheets were characterized by transmission electron microscopy, scanning electron microscopy, and Raman spectrum. It was found that the In2O3 nanosheets were single crystals with body-centered cubic structure and dimensions of about 0.5-3 mu m. A possible mechanism for the In2O3 nanosheet growth was also proposed on the basis of the results of the present and previous works. This mechanism not only can explain all the experimental observations but also helps to clarify the growth mechanism of other nanostructures in the gas phase. A strong and narrow photoluminescent (PL) peak at 428 nm was observed from the nanosheets, which is attributed to radiative recombination between an electron on an oxygen vacancy and a hole on an indium-oxygen vacancy center in the In2O3 nanosheets.