Field Emission from Different Si-Based Nanostructures

Field Emission from Different Si-Based Nanostructures 

It is well known that nanotubes and nanowires with sharp tips are promising materials for application as cold cathode field emission devices. We have investigated the field emission of different nanowire structures. The first is from SiNWS. SiNWs exhibit well-behaved and robust field emission fitting a Fowler-Nordheim (FN) plot. The turn-on field for SiNWs, which is needed to achieve a current density of 0.01 mA cm , was 15 V p.m [26]. The field emission characteristics may be improved by further optimization, such as oriented growth or reducing the oxide shell, and may be promising for applications. 

The second example of field emission of Si-based nanowires is that of B-doped Si nanochains [80]. The SiNCs were attached onto a Mo substrate by a conductive carbon film. The anode-sample separation ranges from 120 to 220 pm. The turn-on field was 6 V pm and smaller than that (15 V pm ) for the SiNWs. The field-emission characteristics of the SiNCs were analyzed according to the FN theory [81]. All the FN curves with different anode-sample separations fall in nearly the same region and have similar Y intercepts, showing that the SiNCs are uniformly distributed. A stability test showed no obvious degradation of current density and the fluctuation was within +15%, indicating that the B-doped SiNCs are a promising material for field emission applications. 

Inset Fowler—Nordheim plot. The linearity of these curves indicates that the emission of the oriented SiC nanowires agrees with the properties expected for field emission [68]. 

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