Field-Emission Characteristics of Zinc Oxide Nanowires Using Low-Temperature Supercritical Carbon Dioxide Fluid Method

Single-crystalline ZnO nanowires (NWs) were directly grown on Zn/glass substrates by using a low-temperature (i.e., 40
^°
C) supercritical carbon dioxide (SCCO
₂
) fluid method. The optical, physical, and field-emission (FE) characteristics of the SCCO
₂
-synthesized ZnO nanostructures are systematically investigated. ZnO NWs exhibited the low turn-on field of 3.16 V/μm at a current density of 10 μA/cm
²
and a low threshold field of 4.38 V/μm at a current density of 1 mA/cm
²
. The current fluctuation of ZnO emitters was less than 8% at 5.3 V/μm in 12 h. The excellent FE properties of SCCO
₂
-synthesized ZnO emitters at low temperature make them a superior candidate for FE-based display devices.