Field emission from cone-like single crystalline indium tin oxide nanorods

Cone-like indium tin oxide (ITO) nanorods were synthesized on Au-coated Si wafers via a carbon thermal reduction vapor transport method. Scanning electron microscopy, X-ray diffraction, and transmission electron microscopy investigations show that these cone-like structured samples present a high-purity single-crystalline cubic bixbyite structure. Field emission characteristics of the ITO nanorods were measured. A low turn-on voltage for driving a current density of 0.1 μA/cm2 is about 3.8 V/μm. A relatively stable emission current was obtained at current density of ∼0.12 mA/cm2 without any degradation in emission for 20 h. The field enhancement factor (γ) was determined to be ∼1140 for ITO nanorods, which is comparable to those of carbon nanotubes.