Synthesis, optical and field emission properties of ZnO microhair-clasps

ZnO microhair-clasps were synthesized on silicon substrate by the vapor-phase transport method at the temperature of 900 °C under atmospheric pressure. The microstructure and morphology of ZnO microhair-clasps were evaluated by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The growth mechanism of the microhair-clasps was investigated. Room temperature photoluminescence spectra of the microhair-clasps showed a weak UV emission band centering at about 388 nm and wide green emissions around 525 nm. Field emission measurements demonstrated that the microhair-clasps with many sharp tips of several nanometers in curvature radius possessed good performance with a turn-on field of ∼1.5 V/μm and a threshold field of ∼4.3 V/μm.