The worm-like AlN nanowires are fabricated by the plasma-enhanced chemical vapor deposition(PECVD)on Si substrates through using Al powder and N2 as precursors,CaF2 as fluxing medium,Au as catalyst,respectively.The as...The worm-like AlN nanowires are fabricated by the plasma-enhanced chemical vapor deposition(PECVD)on Si substrates through using Al powder and N2 as precursors,CaF2 as fluxing medium,Au as catalyst,respectively.The as-grown worm-like AlN nanowires each have a polycrystalline and hexagonal wurtzite structure.Their diameters are about 300 nm,and the lengths are over 10μm.The growth mechanism of worm-like AlN nanowires is discussed.Hydrogen plasma plays a very important role in forming the polycrystalline structure and rough surfaces of worm-like AlN nanowires.The worm-like AlN nanowires exhibit an excellent field-emission(FE)property with a low turn-on field of 4.5 V/μm at a current density of 0.01 mA/cm^(2) and low threshold field of 9.9 V/μm at 1 mA/cm^(2).The emission current densities of worm-like AlN nanowires each have a good stability.The enhanced FE properties of worm-like AlN nanowires may be due to their polycrystalline and rough structure with nanosize and high aspect ratio.The excellent FE properties of worm-like AlN nanowires can be explained by a grain boundary conduction mechanism.The results demonstrate that the worm-like AlN nanowires prepared by the proposed simple and the PECVD method possesses the potential applications in photoelectric and field-emission devices.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11774017 and 51761135129).
文摘The worm-like AlN nanowires are fabricated by the plasma-enhanced chemical vapor deposition(PECVD)on Si substrates through using Al powder and N2 as precursors,CaF2 as fluxing medium,Au as catalyst,respectively.The as-grown worm-like AlN nanowires each have a polycrystalline and hexagonal wurtzite structure.Their diameters are about 300 nm,and the lengths are over 10μm.The growth mechanism of worm-like AlN nanowires is discussed.Hydrogen plasma plays a very important role in forming the polycrystalline structure and rough surfaces of worm-like AlN nanowires.The worm-like AlN nanowires exhibit an excellent field-emission(FE)property with a low turn-on field of 4.5 V/μm at a current density of 0.01 mA/cm^(2) and low threshold field of 9.9 V/μm at 1 mA/cm^(2).The emission current densities of worm-like AlN nanowires each have a good stability.The enhanced FE properties of worm-like AlN nanowires may be due to their polycrystalline and rough structure with nanosize and high aspect ratio.The excellent FE properties of worm-like AlN nanowires can be explained by a grain boundary conduction mechanism.The results demonstrate that the worm-like AlN nanowires prepared by the proposed simple and the PECVD method possesses the potential applications in photoelectric and field-emission devices.
