Structural Changes in a Single GaN Nanowire under Applied Voltage Bias

Sergey Lazarev, Dmitry Dzhigaev, Zhaoxia Bi, Ali Nowzari, Young Yong Kim, Max Rose, Ivan A. Zaluzhnyy, Oleg Yu Gorobtsov, Alexey V. Zozulya, Filip Lenrick, Anders Gustafsson, Anders Mikkelsen, Michael Sprung, Lars Samuelson, Ivan A. Vartanyants

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

GaN nanowires (NWs) are promising building blocks for future optoelectronic devices and nanoelectronics. They exhibit stronger piezoelectric properties than bulk GaN. This phenomena may be crucial for applications of NWs and makes their study highly important. We report on an investigation of the structure evolution of a single GaN NW under an applied voltage bias along polar [0001] crystallographic direction until its mechanical break. The structural changes were investigated using coherent X-ray Bragg diffraction. The three-dimensional (3D) intensity distributions of the NWs without metal contacts, with contacts, and under applied voltage bias in opposite polar directions were analyzed. Coherent X-ray Bragg diffraction revealed the presence of significant bending of the NWs already after metal contacts deposition, which was increased at applied voltage bias. Employing analytical simulations based on elasticity theory and a finite element method (FEM) approach, we developed a 3D model of the NW bending under applied voltage. From this model and our experimental data, we determined the piezoelectric constant of the GaN NW to be about 7.7 pm/V in [0001] crystallographic direction. The ultimate tensile strength of the GaN NW was obtained to be about 1.22 GPa. Our work demonstrates the power of in operando X-ray structural studies of single NWs for their effective design and implementation with desired functional properties.

Original languageEnglish
Pages (from-to)5446-5452
Number of pages7
JournalNano Letters
Volume18
Issue number9
DOIs
Publication statusPublished - 12 Sep 2018

Keywords

  • coherent X-ray Bragg diffraction
  • finite element method
  • GaN nanowires
  • piezoelectric effect

ASJC Scopus subject areas

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

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  • Cite this

    Lazarev, S., Dzhigaev, D., Bi, Z., Nowzari, A., Kim, Y. Y., Rose, M., Zaluzhnyy, I. A., Gorobtsov, O. Y., Zozulya, A. V., Lenrick, F., Gustafsson, A., Mikkelsen, A., Sprung, M., Samuelson, L., & Vartanyants, I. A. (2018). Structural Changes in a Single GaN Nanowire under Applied Voltage Bias. Nano Letters, 18(9), 5446-5452. https://doi.org/10.1021/acs.nanolett.8b01802