Optimizing the yield of A-polar GaAs nanowires to achieve defect-free zinc blende structure and enhanced optical functionality

Research output: Contribution to journalArticle

Abstract

Compound semiconductors exhibit an intrinsic polarity, as a consequence of the ionicity of their bonds. Nanowires grow mostly along the (111) direction for energetic reasons. Arsenide and phosphide nanowires grow along (111)B, implying a group V termination of the (111) bilayers. Polarity engineering provides an additional pathway to modulate the structural and optical properties of semiconductor nanowires. In this work, we demonstrate for the first time the growth of Ga-assisted GaAs nanowires with (111)A-polarity, with a yield of up to ∼50%. This goal is achieved by employing highly Ga-rich conditions which enable proper engineering of the energies of A and B-polar surfaces. We also show that A-polarity growth suppresses the stacking disorder along the growth axis. This results in improved optical properties, including the formation of AlGaAs quantum dots with two orders or magnitude higher brightness. Overall, this work provides new grounds for the engineering of nanowire growth directions, crystal quality and optical functionality.

Details

Authors
  • Mahdi Zamani
  • Gözde Tütüncüoglu
  • Sara Martí-Sánchez
  • Luca Francaviglia
  • Lucas Güniat
  • Lea Ghisalberti
  • Heidi Potts
  • Martin Friedl
  • Edoardo Markov
  • Wonjong Kim
  • Jean-Baptiste Leran
  • Vladimir G Dubrovskii
  • Jordi Arbiol
  • Anna Fontcuberta I Morral
External organisations
  • Swiss Federal Institute of Technology
Original languageEnglish
Pages (from-to)17080-17091
Number of pages12
JournalNanoscale
Volume10
Issue number36
Publication statusPublished - 2018 Sep 20
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes