Wavelength-Emission Tuning of ZnO Nanowire-Based Light-Emitting Diodes by Cu Doping: Experimental and Computational Insights

Authors

  • Oleg Lupan,

    1. Chimie ParisTech, Laboratoire d'Electrochimie, Chimie aux Interfaces et Modélisation pour l'Energie (LECIME), UMR 7575 CNRS, 11 rue P. et M. Curie, 75231 Paris, cedex 05, France
    Current affiliation:
    1. Department of Microelectronics and Semiconductor Devices, Technical University of Moldova, 168 Stefan cel Mare Blvd., Chisinau, MD-2004, Republic of Moldova
    Search for more papers by this author
  • Thierry Pauporté,

    Corresponding author
    1. Chimie ParisTech, Laboratoire d'Electrochimie, Chimie aux Interfaces et Modélisation pour l'Energie (LECIME), UMR 7575 CNRS, 11 rue P. et M. Curie, 75231 Paris, cedex 05, France
    • Chimie ParisTech, Laboratoire d'Electrochimie, Chimie aux Interfaces et Modélisation pour l'Energie (LECIME), UMR 7575 CNRS, 11 rue P. et M. Curie, 75231 Paris, cedex 05, France.
    Search for more papers by this author
  • Tangui Le Bahers,

    1. Chimie ParisTech, Laboratoire d'Electrochimie, Chimie aux Interfaces et Modélisation pour l'Energie (LECIME), UMR 7575 CNRS, 11 rue P. et M. Curie, 75231 Paris, cedex 05, France
    Search for more papers by this author
  • Bruno Viana,

    1. Chimie ParisTech, Laboratoire de Chimie de la Matière Condensée de Paris, UMR 7574, 11 rue P. et M. Curie, 75231 Paris cedex 05, France
    Search for more papers by this author
  • Ilaria Ciofini

    1. Chimie ParisTech, Laboratoire d'Electrochimie, Chimie aux Interfaces et Modélisation pour l'Energie (LECIME), UMR 7575 CNRS, 11 rue P. et M. Curie, 75231 Paris, cedex 05, France
    Search for more papers by this author

Abstract

The band-gap engineering of doped ZnO nanowires is of the utmost importance for tunable light-emitting-diode (LED) applications. A combined experimental and density-functional theory (DFT) study of ZnO doping by copper (Zn2+ substitution by Cu2+) is presented. ZnO:Cu nanowires are epitaxially grown on magnesium-doped p-GaN by electrochemical deposition. The heterojunction is integrated into a LED structure. Efficient charge injection and radiative recombination in the Cu-doped ZnO nanowires are demonstrated. In the devices, the nanowires act as the light emitters. At room temperature, Cu-doped ZnO LEDs exhibit low-threshold emission voltage and electroluminescence emission shifted from the ultraviolet to violet–blue spectral region compared to pure ZnO LEDs. The emission wavelength can be tuned by changing the copper content in the ZnO nanoemitters. The shift is explained by DFT calculations with the appearance of copper d states in the ZnO band-gap and subsequent gap reduction upon doping. The presented data demonstrate the possibility to tune the band-gap of ZnO nanowire emitters by copper doping for nano-LEDs.

Ancillary