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arXiv · 2008.03003

Field emission from AlGaN nanowires with low turn-on field

Filippo Giubileo·Antonio Di Bartolomeo·Yun Zhong·Songrui Zhao·Maurizio Passacantando
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Abstract

We fabricate AlGaN nanowires by molecular beam epitaxy and we investigate their field emission properties by means of an experimental setup using nano-manipulated tungsten tips as electrodes, inside a scanning electron microscope. The tip-shaped anode gives access to local properties and allows collecting electrons emitted from areas as small as 1$μm^2$. The field emission characteristics are analyzed in the framework of Fowler-Nordheim theory and we find a field enhancement factor as high as $β$ = 556 and a minimum turn-on field $E_{turn-on}$ = 17 V/$μ$m for a cathode-anode separation distance d = 500 nm. We show that for increasing separation distance, $E_{turn-on}$ increases up to about 35 V/$μ$m and $β$ decreases to 100 at d = 1600 nm. We also demonstrate the time stability of the field emission current from AlGaN nanowires for several minutes. Finally, we explain the observation of modified slope of the Fowler-Nordheim plots at low fields in terms of non-homogeneous field enhancement factors due to the presence of protruding emitters.

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Filippo Giubileo, Antonio Di Bartolomeo, Yun Zhong, Songrui Zhao, Maurizio Passacantando. 2020-08-07. Field emission from AlGaN nanowires with low turn-on field. https://arxiv.org/abs/2008.03003

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