Phonon-assisted field emission from W18O49 nanowires

Temperature dependence of field emission characteristics of tungsten sub-oxide (W18O49) nanowires was investigated in the range from 143 K to room temperature. It is found that the field emission currents under the same applied electrical field decrease with the decreasing temperature. A two-step process involving the phonon-assisted tunneling from defect states to conduction band was introduced to explain the observed phenomenon. A good agreement between the theoretical and experimental results was achieved. (C) 2013 AIP Publishing LLC.