Giant piezoelectric size effects in zinc oxide and gallium nitride nanowires. A first principles investigation

Ravi Agrawal, Horacio D. Espinosa

Research output: Contribution to journalArticlepeer-review

219 Scopus citations

Abstract

Nanowires made of materials with noncentrosymmetric crystal structure are under investigation for their piezoelectric properties and suitability as building blocks for next-generation self-powered nanodevices. In this work, we investigate the size dependence of piezoelectric coefficients in nanowires of two such materials - zinc oxide and gallium nitride. Nanowires, oriented along their polar axis, ranging from 0.6 to 2.4 nm in diameter were modeled quantum mechanically. A giant piezoelectric size effect is identified for both GaN and ZnO nanowires. However, GaN exhibits a larger and more extended size dependence than ZnO. The observed size effect is discussed in the context of charge redistribution near the free surfaces leading to changes in local polarization. The study reveals that local changes in polarization and reduction of unit cell volume with respect to bulk values lead to the observed size effect. These results have strong implication in the field of energy harvesting, as piezoelectric voltage output scales with the piezoelectric coefficient.

Original languageEnglish (US)
Pages (from-to)786-790
Number of pages5
JournalNano letters
Volume11
Issue number2
DOIs
StatePublished - Feb 9 2011

Keywords

  • Gallium nitride
  • density functional theory
  • nanowires
  • piezoelectric properties
  • zinc oxide

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Giant piezoelectric size effects in zinc oxide and gallium nitride nanowires. A first principles investigation'. Together they form a unique fingerprint.

Cite this