On the piezoelectric potential of gallium nitride nanotubes

J Zhang and SA Meguid, NANO ENERGY, 12, 322-330 (2015).

DOI: 10.1016/j.nanoen.2014.12.036

The piezoelectric potential of strained intrinsic gallium nitride (GaN) nanotubes (NTs) has been studied analytically and numerically. The material properties used are obtained from molecular dynamics simulations (MDSs) and found to depend on the temperature and the NT's wall thickness. A novel core-surface model is developed to explain the size-dependent phenomenon and also used to predict the material properties for large-scale structures, where MDSs are not feasible. The obtained results show that GaN NTs can generate a much higher piezoelectric potential than their nanowire (NW) counterparts due to distinct material and geometric properties of NTs. This observation is not only limit for the present intrinsic structures but also can be expected for the as-grown structures. The influence of material and geometric properties becomes more significant for NTs with smaller radius or wall thickness-to-radius ratio and may enhance the piezoelectric potential by up to ten times for intrinsic NTs. However, the temperature is found to have no significant influence on the improvement of the piezoelectric potential of NTs. The observed improved piezoelectric potential in GaN NTs together with some other advantages of NTs, such as more efficient surface functionalization, suggests that the GaN NT can be a better candidate for the building blocks in piezotronic nanodevices compared with the most commonly used NWs. (C) 2014 Elsevier Ltd. All rights reserved.

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