Boron nanotubes (BNTs) have been theoretically proposed to have metallic properties whether they are in armchair or zigzag structure, so they have attracted much interest from researchers. However, their real properties have been not understood until now because they are hard to synthesize. In this paper, we have successfully fabricated a large quantity of boron nanotubes, which may provide a way to master their electric and field emission (FE) properties. Study on individual boron nanotubes shows that BNTs have metallic properties with an averaged conductivity of 40 Ω⁻¹cm⁻¹. Moreover, individual BNTs can sustain a high current of about 80 μA and their current density can reach 2.04 × 10¹¹ A m⁻², which is very close to those of CNTs. They are also incorporated into prototype luminescent tube devices for the first time and exhibit high luminescent efficiency and stability, which suggests that BNTs have a promising future in the FE area.

Strong photoluminescence (PL) is observed in nanostructured crystalline tungsten oxide thin films that are prepared by thermal evaporation. Two kinds of films are investigated—one made of nanoparticles and another of nanowires. At room temperature, strong PL emissions at ultraviolet-visible and blue regions are found in both of the films. Compared with the complete absence of emission of bulk phase tungsten oxide powder under the same excitation conditions, our results clearly demonstrate the quantum-confinement-effect-induced photoluminescence in nanostructured tungsten oxides.