Laiqiang Luo

Effect of high-energy ball milling on morphology and field emission properties of multi-walled carbon nanotubes

The effects of grinding for different time in a vibrating mill with the mixture of Fe powder and multi-walled carbon nanotubes (MWNTs) were studied. The morphology and structure of as-ground MWNTs were carried out by X-ray diffraction (XRD) and High-resolution transmission electronic microscopy (HRTEM). The results showed that some closed ends of MWNTs were broken while ground for 8 hours, and the rate of broken ends increased with grinding time. The Field emission measurements demonstrated that the turn-on field of the sample decreased from 4.0 to 2.6 V/μm after grinding.

Efficient field emission from porous silicon

Patterned porous silicon (PS) films were fabricated based on hydrogen ion implantation technique and typical electrochemical anodic etching method. The surface morphology and characteristics of the films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscopy (AFM). The efficient field emission with low turn-on field of about 3.5V/μm at current density of 0.1μA/cm2 was obtained. The emission current density from the PS films reached 1mA/cm2 under a applied field of about 12.5V/μm. The experimental results demonstrate that the PS films have great potential applications for flat panel displays.

Bond enhance of hydroxyapatite/silicon layers by introducing a porous silicon interlayer

Hydroxyapatite (HAP) nano-particles obtained by coprecipitate process are deposited on porous silicon substrates, after being annealed, HAP films connected tightly with porous silicon substrates. The resulted samples were investigated by XRD, AFM and SEM.

Field emission behavior of GaN nanoparticles and nanobelts

Gallium nitride (GaN) nanoparticles and nanobelts films are successfully synthesized on Si (111) substrates through ammoniating Ga2O3 thin films deposited by radio frequency magnetron sputtering. X-ray diffraction (XRD), scanning electronic microscope (SEM), transmission electronic microscope (TEM) are carried out to analyze as-synthesized GaN products. The field emission measurements show that the as-synthesized GaN nanoparticles and nanobelts have lower turn-on field of 5.8 and 6.1V/μm at the current density of 0.1μA/cm2, respectively. It is found that the Fowler-Nordheim (FN) plot of nanobelts exhibits nonlinearity. The experimental results demonstrated that there were great potential applications of the GaN nanoparticles and nanobelts for flat panel displays.