Synthesis and field emission properties of needle-shaped SnO2 nanostructures with rectangular cross-section

Large-scale novel needle-shaped SnO2 nanostructures were produced via a thermal evaporation method and their possible growth mechanism is proposed. The products, which gradually become thinner to form a sharp tip, had preferred growth directions. Efficient and stable field emission is obtained from these SnO2 nanostructures. The current density is up to 3 mA/cm2 at 5.93 V/μm and the fluctuation of FE (field emission) currents is as small as 8% over 2 h. Our results imply that needle-shaped SnO2 nanostructures are promising candidate for FE displays.