Anomalous temperature dependence of field emission from W18O49 nanowires caused by surface states and field penetration

Abstract

In this paper, we studied how field emission from thermally evaporated W18O49 nanowires depended on temperature. As the temperature changed from 300 K to 723 K, we found anomalous changes in emission current. Below an applied field of ∼12.5 V μm−1, the emission current tended to increase with rising temperature, while above 12.5 V μm−1 the current depended less on temperature in the range of 573–723 K. Furthermore, at high temperatures, we found the Fowler-Nordheim plots of these nanowires to be nonlinear. We believe that the anomalous behavior is associated with surface states at low fields and field penetration at high fields.

Noise Modeling in Field Emission and Evaluation of the Nano-Receiver in Terms of Temperature

“…As described in Section II, the temperature dependence can be discussed based on this law. This point has been demonstrated with various emitters, including W 18 O 49 nanowires [38], VO 2 nanogap emitters [39], SiC@SiO 2 @graphene nanoarray [35] and WS 2 nanosheets [43]. Because our developed model originates from the general model of the Fowler-Nordheim equation, and the obtained exponential trend agrees with the result in the literature, a similar discussion is possible for other types of field emitters.…”

“…In the past several decades, the general The associate editor coordinating the review of this manuscript and approving it for publication was Emrecan Demirors. theory has been discussed in the literatures, e.g., [31], [32], and experimental demonstrations have been provided for various types of emitters, including thermally grown SiO 2 emitters [33], carbon-based emitters [34]- [37], and W 18 O 49 nanowires [38]. As the temperature increases, the obtained current is enhanced.…”

Change in crystalline structure of W18O49nanowires induced by X-ray irradiation and its effects on field emission

“…Excellent eld emission performance, including low turn-on eld, high current density, good stability, and high uniformity, has been reported for various one-dimensional tungsten oxide nanomaterials. [19][20][21][22][23][24][25][26][27][28][29] For example, in 2003, Li et al reported that W 18 O 49 nanotubes and nanowires can be prepared by heating tungsten foil under vacuum conditions and investigated their eld emission properties; the turn-on eld was only 2.6 MV m À1 . 19 Zhou et al used two thermal evaporation processes to grow W 18 O 49 nanotips; stable eld emission with uctuation of 2.0% at an emission current of 1200 mA over 13 hours and a low turn-on eld of 2.0 MV m À1 were obtained.…”

“…22 On the other hand, improvements in the eld mission performance of tungsten oxide nanomaterials have also been studied, such as tuning the ratio of WO 2 and WO 2.9 , 24 electric treatment, 25 and plasma treatment. 26 The effect of environment temperature 27,28 and atomic oxygen exposure 29 on the eld emission properties of tungsten oxide nanowires have also been reported in attempts to determine the emission mechanism of metal oxide eld emitters.…”

Band-to-Band Tunneling-Dominated Thermo-Enhanced Field Electron Emission from p-Si/ZnO Nanoemitters

“…The thermo-enhanced field emission demonstrations so far are all based on the interband or intraband defect state excitation mechanisms. The field emission current from a metal or n-doped semiconductor thermo-enhanced emitter is less temperature sensitive due to the weak dependence of free electron density on temperature , unless electron trap centers are introduced. , However, the quantity of electron trap centers is difficult to control. Gas adsorption can also influence the thermo-enhanced field emission properties, but this factor is still unpredictable.…”