Structure and enhanced field emission properties of cone-shaped Zn-doped SnO2 nanorod arrays on copper foil

• The cone-shaped Zn–SnO2 nanorod arrays are hydrothermally synthesized.
• The Zn doping play an important role in tuning the morphology of SnO2 nanorods.
• The structural and FE properties of cone-like Zn–SnO2 nanorod arrays are studied.

Single crystal Zn-doped SnO2 (Zn–SnO2) nanorods with cone-shaped tips (~25 nm) on copper foil were synthesized by an organic-free hydrothermal method. The effects of the Zn doping on the morphology, microstructure and field-emission (FE) properties of Zn–SnO2 were investigated. It is found that the Zn doping play an important role in tuning the morphology and size of the SnO2 nanorods. The turn-on fields of SnO2 and Zn–SnO2 nanorods were 3.16 and 2.37 V/μm, and field enhancement factors (β) were 960 and 3352, respectively. The enhanced FE property is due to the tapered structures of nanorods with sharp tips and the weak screening effect, and the better electrical contact between conductive copper substrate and field emitters.