Controllable synthesis of indium oxide nanorod-flowers for high field emission performance

In this paper, indium oxide (In₂O₃) nanomaterials are successfully synthesized on the silicon substrates by hydrothermal method and calcination. By changing the ratio of raw materials, In₂O₃ exhibits three morphologies of nanorods, nanomaces, and nanorod-flowers. Among the three morphologies of In₂O₃ nanomaterials, the nanorod-flowers shaped In₂O₃ shows a strong field emission property, the turn-on electric field as low as 0.97 V/µm and the field enhancement factor β up to 1053. The excellent performance is attributed to the higher length to diameter (L/D) ratio of the emitting tips and the better crystal quality for nanorod-flowers shaped In₂O₃. The authors also show that for the nanorod-flowers shaped In₂O₃, increasing separation distance, the turn-on electric field increases up to about 3.67 V/µm and β decreases to 573 at d = 900 µm. This work provides new insights to design and synthesize nanomaterials with excellent field emission properties.