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Two-dimensional (2D) metallic transition metal dichalcogenides (TMDs) exhibit fascinating quantum effects, such as charge-density-wave (CDW) and weak antilocalization (WAL) effect. Herein, low temperature synthesis of 1T phase VSe

Two-dimensional (2D) metallic transition metal dichalcogenides (TMDs) exhibit fascinating quantum effects, such as charge-density-wave (CDW) and weak antilocalization (WAL) effect. Herein, low temperature synthesis of 1T phase VSe2 single crystals with thickness ranging from 3 to 41 nm by chemical vapor deposition (CVD) is reported. The VSe2 shows a decreasing phase transition temperature of the CDW when the thickness is decreased. Moreover, low-temperature magnetotransport measurements demonstrate a linear positive and non-saturating magnetoresistance (MR) of 35% from a 35 nm thick VSe2 at 15 T and 2 K due to CDW induce mobility fluctuations. Surprisingly, Kohler's rule analysis of the MR reveals the non-applicability of Kohler's rule for temperature above 50 K indicating that the MR behavior cannot be described in terms of semiclassical transport on a single Fermi surface with a single scattering time. Furthermore, WAL effect is observed in the 4.2 nm thick VSe2 at low magnetic fields at 2 K, revealing the contribution of the quantum interference effect at the 2D limit. The phase coherence length [Formula: see text] and spin-orbit scattering length [Formula: see text] were determined to be 73 nm and 18 nm at 2 K, respectively. Our work opens new avenues to study the fundamental quantum phenomena in CVD-deposited TMDs.

The secondary electron emission (SEE) of ZnO-coated carbon nanotubes (CNTs) was measured using a biasing technique in a scanning electron microscope. The SEE yield of the ZnO-coated CNTs is higher than that of the ZnO film deposited on Si substrates. Direct observation of the variation in SEE from tip-end and non-CNT positions was demonstrated. Local measurement reveals that the SEE yield at the tip-end of the ZnO-coated CNTs is much higher than that of non-CNT positions. The enhancement of SEE is attributed to the strong local field generated at the tip of the CNTs.

We report the synthesis of aligned wurtzite InN nanofingers by the ion-beam assisted filtered cathodic vacuum arc technique. InN nanofingers exhibit a polycrystalline structure. Photoluminescence (PL) and field emission properties of the InN nanofingers were studied. The PL emission peak was centred at ~1.1 eV with a full width at half maximum of 105 meV. The field emission characteristic was observed from the InN nanofingers with turn-on field of 9.7 V µm−1 at a current density of 10 µA cm−2. The formation of InN nanofingers was attributed to the Volmer–Weber growth mode.

The electron field emission from zinc oxide (ZnO) nanoneedles on flexible plastic substrates is reported. ZnO thin films were first deposited on plastic substrates at 200 °C using a filtered cathodic vacuum arc technique; the films were then bombarded by Ar+ ion. After ion beam irradiation, high-density ZnO nanoneedle arrays were selectively formed on the thin films. The average diameter and length of the ZnO nanoneedles is around 100 and 700 nm respectively. Field emission measurement showed a fairly low threshold voltage of 4.1 V µm−1 with a current density of 1 µA cm−2. The emission current density can be as high as 1 mA cm−2 at 9.6 V µm−1. The result establishes a method of fabricating a flexible field emitter, which should find practical applications in vacuum electronic devices.

Carbon nanotubes (CNTs) and zirconium carbide (ZrC) composite films were directly grown on Zr–Fe coated glass by chemical vapour deposition. The Zr–Fe film not only acts as a catalyst to facilitate the nanotube growth, but also offers a template to form the ZrC phase. The Zr content in the Zr–Fe bimetallic catalyst can influence the carbon production rate so as to grow long CNTs, yielding a high aspect ratio. In comparison with CNTs grown on a pure Fe catalyst, the composite film promotes the growth of sparse and long nanotubes. Field emission measurements revealed that the composite film exhibits a relatively low turn-on field of 3.2 V µm−1.

In this study, the use of flexographic printing was investigated for low cost, high volume production of devices incorporating nanowires through the printing of zinc acetate precursors on a substrate used to form zinc oxide (ZnO) seeds for the growth of nanowires using a hydrothermal growth technique. The printing of precursors allows the selective area growth of ZnO nanowires, which has implications in high-yield production of devices incorporating ZnO nanowires. The work presented here achieved printed line widths of

Copper-doped AlN (AlN:Cu) nanorods were grown on catalyst-free Si substrates by chemical vapour deposition. The AlN:Cu nanorods exhibited the wurtzite structure with a growth direction along the c-axis. Ferromagnetic ordering of the AlN:Cu nanorods was observed at room temperature by an alternating gradient magnetometer. The spontaneous magnetization and the coercivity of the AlN:Cu nanorods are about 0.38?emu?cm?3 and 100?Oe, respectively. The results reveal that Cu is a potential nonmagnetic dopant for AlN.