Junjie Niu

Arrays of ZnO nanowires fabricated by a simple chemical solution route

A sol–gel process and a nanochannel aluminium template were employed to fabricate an orderly array of ZnO nanowires. The ZnO nanowires, with a hexagonal structure, were identified by means of x-ray diffraction and selected-area electron diffraction. The arrays of ZnO nanowires were characterized by scanning electron microscopy. Transmission electron microscopy (TEM) shows that the diameters of the ZnO nanowires are very uniform, at about 60 nm. Furthermore, high-resolution TEM provides lattice images of {100}, {002} and {101} planes in the nanowires, indicating that the nanowires are well crystallized.

Directional CdS nanowires fabricated by chemical bath deposition

Directional CdS nanowires have been fabricated by using chemical bath deposition (CBD) and porous anodic aluminum oxide (AAO) template. X-ray diffraction and selected area electron diffraction show that the nanowires are hexagonal polycrystalline in nature. Transmission electron microscopy (TEM) reveals that the diameters of nanowires are about 60 nm. Furthermore, the high-resolution TEM illustrates the lattice images of {0 0 2}, {1 0 1} and {1 0 0} planes in the nanowires. The directional growth of nanowires is verified by scanning electron microscopy. It is believed that the ion-by-ion mechanism dictates the CBD of CdS nanowires within the pores of AAO template.

Array-orderly single crystalline silicon nano-wires

Array-orderly single crystal silicon nano-wires (SiNWs) using self-organized nano-holes of anodically oxidized aluminum were fabricated. By field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM), the well-orderly single crystal SiNWs arrays were observed. The interval of the SiNWs is excellent symmetrical and consentaneous. The diameter and the length are around 35 nm and 4 μm, respectively. Furthermore, the energy dispersive X-ray spectroscopy analysis (EDX) indicated that the SiNWs consist of silicon core and silicon oxide sheath mainly. The Raman scattering was also carried out to analyze the structure of the oriented SiNWs. Finally, the growth mechanism of the SiNWs was discussed.

Crystallization and disappearance of defects of the annealed silicon nanowires

The crystallization and the disappearance of the defects and impurity stress of silicon nanowires (SiNWs) after annealing at high temperature (900 °C) have been investigated. The chemical-vapor-deposition (CVD) and alumina template technology were used for the synthesis of the SiNWs. Then transmission electron microscopy (TEM), selected-area electron diffraction (SAED) and photoluminescence (PL) spectra were used to study the crystallization procedure and the disappearance of defects of the SiNWs.

Crystallization and Raman Shift of Array-Orderly Silicon Nanowires after Annealing at High Temperature

Ordered silicon nanowires (SiNWs) with single crystal structure were synthesized using nanochannel-Al2O3 (NCA) and the chemical vapor deposition (CVD) method. Firstly, the SiNWs with nearly amorphous structure were fabricated at 500°C; then the SiNWs with crystalline structure were obtained by annealing an as-received sample at 800°C. The average diameter and length of the SiNWs are 40–70 nm and 10 µm, respectively. The Raman shift related to the crystallization and the amorphous SiNWs was analyzed.

Synthesis of boron and boride compounds nanowire arrays by chemical vapor deposition

Aligned single crystal boron nanowires (BNWs) were fabricated by CVD process in nano-channel Al/sub 2/O/sub 3/ (NCA) substrates at 800/spl deg/C. Using boron nanowires as precursors, arrayed single crystal hexagonal MgB/sub 2/ nanowires were fabricated by reacting BNWs in NCA with Mg vapor in a sealed vacuum quartz tube. And it is indicated that the nanowires had a superconducting transition temperature (T/sub c/) at /spl sim/35 K. Mg/sub 3/B/sub 2/O/sub 6/ nanowires were fabricated in-situ at 950/spl deg/C by reacting Mg, diborane and traces of oxygen. The growth mechanisms of these nanowires have been discussed.

A novel sulfide-assisted growth of silicon nano-wires

A large-scale SiNWs with the diameter of /spl sim/20-30 nm and the length of tens of micrometers formed on silicon substrates using a novel evaporation of sulfides (sulphur and zinc sulfide) at /spl sim/1080/spl deg/C were synthesized; The source of SiNWs came from silicon wafers rather than silane gas as reported before. It was found that the tip of SiNWs contained sulfur, while the other positions of SiNWs did not. It is considered that the decomposition of SiS resulted in the formation of SiNWs. As referring to the oxygen-assisted growth model of SiNWs by evaporation of silicon oxide, a corresponding sulfide-assisted model was suggested.