Field emission of point-electron source Mo_6S_3I_6 nanowires

摘要

The field emission (FE) properties of nanowires made from the recently synthesized nanowire material Mo_6S_3I_6 are reported. A single nanowire was mounted on an indium-coated nickel holder by dielectrophoresis in isopropyl alcohol. A careful activation or conditioning in a vacuum of 10~7 mbar was shown to be indispensable in order to extract relatively stable FE currents in excess of 1 mu A originating from only a few sites at the end of the nanowire. Measurements were performed in an FE microscope with an additional plane mesh, which enables us to record I-U characteristics in diode mode, or to observe the emission patterns in triode mode. With FE currents around 5-1 mA the emitter degrades gradually, and to some extent irreversibly. The degradation mechanism is not a reversal of the instant site build-up.