Enhanced field emission properties of IrO2 coated carbon nanotube bundle arrays

In order to enhance field emission (FE) property of carbon nanotubes (CNTs), IrO
₂
nanocrystals (NCs) were coated on the patterned CNT bundle arrays via reactive RF magnetron sputtering. The properties of IrO
₂
/CNTs composites were characterized by field-emission scanning electron microscopy and transmission electron microscopy. Based on the combined effects of geometrical structure of IrO
₂
/CNTs composites, and the natural conductor and enhanced resistance to oxidation properties of IrO
₂
, a low turn-on field of 0.7 V/¿m at a current density of 0.1 ¿A/cm
²
, a low threshold field of 2.3 V/¿m at a current density of 1 mA/cm
²
, a high field enhancement factor of 4 × 10
⁵
, and a long-term stability have been achieved for the IrO
₂
coated patterned CNT bundle arrays.