Individual GaN nanowires exhibit strong piezoelectricity in 3D

Majid Minary-Jolandan, Rodrigo A. Bernal, Irma Kuljanishvili, Victor Parpoil, Horacio D. Espinosa

Research output: Contribution to journalArticlepeer-review

111 Scopus citations

Abstract

Semiconductor GaN NWs are promising components in next generation nano- and optoelectronic systems. In addition to their direct band gap, they exhibit piezoelectricity, which renders them particularly attractive in energy harvesting applications for self-powered devices. Nanowires are often considered as one-dimensional nanostructures; however, the electromechanical coupling leads to a third rank tensor that for wurtzite crystals (GaN NWs) possesses three independent coefficients, d 33, d 13, and d 15. Therefore, the full piezoelectric characterization of individual GaN NWs requires application of electric fields in different directions and measurements of associated displacements on the order of several picometers. In this Letter, we present an experimental approach based on scanning probe microscopy to directly quantify the three-dimensional piezoelectric response of individual GaN NWs. Experimental results reveal that GaN NWs exhibit strong piezoelectricity in three dimensions, with up to six times the effect in bulk. Based on finite element modeling, this finding has major implication on the design of energy harvesting systems exhibiting unprecedented levels of power density production. The presented method is applicable to other piezoelectric NW materials as well as wires manufactured along different crystallographic orientations.

Original languageEnglish (US)
Pages (from-to)970-976
Number of pages7
JournalNano Letters
Volume12
Issue number2
DOIs
StatePublished - Feb 8 2012
Externally publishedYes

Keywords

  • GaN NWs
  • nanogenerators
  • Piezoelectricity
  • piezoresponse force microscopy
  • scanning probe microscopy

ASJC Scopus subject areas

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

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