Low-Temperature Preparation of Ag-Doped ZnO Nanowire Arrays, DFT Study, and Application to Light-Emitting Diode.

Doping ZnO nanowires (NWs) by group IB elements is an important challenge for integrating nanostructures into functional devices with better and tuned performances. The growth of Ag-doped ZnO NWs by electrodeposition at 90 °C using a chloride bath and molecular oxygen precursor is reported. Ag acts as an electrocatalyst for the deposition and influences the nucleation and growth of the structures. The silver atomic concentration in the wires is controlled by the additive concentration in the deposition bath and a content up to 3.7 atomic % is reported. XRD analysis shows that the integration of silver enlarges the lattice parameters of ZnO. The optical measurements also show that the direct optical bandgap of ZnO is reduced by silver doping. The bandgap shift and lattice expansion are explained by first principle calculations using the density functional theory (DFT) on the silver impurity integration as an interstitial (Ag(i)) and as a substitute of zinc atom (Ag(Zn)) in the crystal lattice. They notably indicate that Ag(Zn) doping forms an impurity band because of Ag 4d and O 2p orbital interactions, shifting the Fermi level toward the valence band. At least, Ag-doped ZnO vertically aligned nanowire arrays have been epitaxially grown on GaN(001) substrate. The heterostructure has been inserted in a light emitting device. UV-blue light emission has been achieved with a low emission threshold of 5 V and a tunable red-shifted emission spectrum related to the bandgap reduction induced by silver doping of the ZnO emitter material.

[1]  O. Nur,et al.  Tuning the emission of ZnO nanorods based light emitting diodes using Ag doping , 2014 .

[2]  S. Chang,et al.  Doped ZnO 1D nanostructures: synthesis, properties, and photodetector application. , 2014, Small.

[3]  T. Pauporté.  Preparation of ZnO Nanorods and Nanowires by Wet Chemistry , 2014 .

[4]  C. Reynolds,et al.  Progress in ZnO Acceptor Doping: What Is the Best Strategy? , 2014 .

[5]  T. Pauporté,et al.  Effects of Oxide Nanoparticle Size and Shape on Electronic Structure, Charge Transport, and Recombination in Dye-Sensitized Solar Cell Photoelectrodes , 2014 .

[6]  Thierry Gacoin,et al.  Controlled Mixed Violet−Blue−Red Electroluminescence from Eu:Nano-Phosphors/ZnO-Nanowires/p‑GaN Light-Emitting Diodes , 2013 .

[7]  D. He,et al.  Preparation and characterization of electrodeposited Ag-doped ZnO inverse opals with a smooth surface , 2013, Journal of Porous Materials.

[8]  Donglin Li,et al.  Stable p-type ZnO films dual-doped with silver and nitrogen , 2013 .

[9]  Oleg Lupan,et al.  ighly sensitive and selective hydrogen single-nanowire nanosensor , 2012 .

[10]  J. Cui,et al.  Mechanism of Ag Doping in ZnO Nanowires by Electrodeposition: Experimental and Theoretical Insights , 2012 .

[11]  Xiaodong Zhang,et al.  Electronic structure and optical transition in heavy metal doped ZnO by first-principle calculations , 2012 .

[12]  Bruno Viana,et al.  Electrodeposition of Cu-doped ZnO nanowire arrays and heterojunction formation with p-GaN for color tunable light emitting diode applications , 2011 .

[13]  Ilaria Ciofini,et al.  Wavelength‐Emission Tuning of ZnO Nanowire‐Based Light‐Emitting Diodes by Cu Doping: Experimental and Computational Insights , 2011 .

[14]  T. Pauporté,et al.  From nanowires to hierarchical structures of template-free electrodeposited ZnO for efficient dye-sensitized solar cells , 2011 .

[15]  Ilaria Ciofini,et al.  High Aspect Ratio Ternary Zn1–xCdxO Nanowires by Electrodeposition for Light-Emitting Diode Applications , 2011 .

[16]  M. Aida,et al.  In doped ZnO thin films , 2011 .

[17]  Xian Zhao,et al.  Structural, Electronic, and Optical Properties of Ag-Doped ZnO Nanowires: First Principles Study , 2011 .

[18]  W. Cheng,et al.  Density Functional Theory Simulations of Structures and Properties for Ag-Doped ZnO Nanotubes , 2011 .

[19]  B. Viana,et al.  Low-Temperature Growth of ZnO Nanowire Arrays on p-Silicon (111) for Visible-Light-Emitting Diode Fabrication , 2010 .

[20]  Thierry Pauporté,et al.  Low‐Voltage UV‐Electroluminescence from ZnO‐Nanowire Array/p‐GaN Light‐Emitting Diodes , 2010, Advanced materials.

[21]  V. Ursaki,et al.  Epitaxial Electrodeposition of ZnO Nanowire Arrays on p-GaN for Efficient UV-Light-Emitting Diode Fabrication , 2010 .

[22]  Alfons Schulte,et al.  Synthesis and Characterization of Ag- or Sb-Doped ZnO Nanorods by a Facile Hydrothermal Route , 2010 .

[23]  C. Shan,et al.  Influence of oxygen/argon ratio on structural, electrical and optical properties of Ag-doped ZnO thin films , 2010 .

[24]  Jingbiao Cui,et al.  Electrochemical Route to p-Type Doping of ZnO Nanowires , 2010 .

[25]  T. Pauporté,et al.  Well-Aligned ZnO Nanowire Arrays Prepared by Seed-Layer-Free Electrodeposition and Their Cassie−Wenzel Transition after Hydrophobization , 2010 .

[26]  Shuyi Ma,et al.  A comparative study of the microstructures and optical properties of Cu- and Ag-doped ZnO thin films , 2009 .

[27]  Anderson Janotti,et al.  Fundamentals of zinc oxide as a semiconductor , 2009 .

[28]  I. Ciofini,et al.  Modeling ZnO phases using a periodic approach: from bulk to surface and beyond. , 2009, The Journal of chemical physics.

[29]  Do Yun Kim,et al.  Investigation of p-type behavior in Ag-doped ZnO thin films by E-beam evaporation , 2009 .

[30]  D. Lincot,et al.  Mechanistic study of ZnO nanorod array electrodeposition , 2008 .

[31]  Y. Zou,et al.  Correlation between electrical, optical properties and Ag2+ centers of ZnO:Ag thin films , 2008 .

[32]  D. R. Sahu,et al.  Studies on the properties of sputter-deposited Ag-doped ZnO films , 2007, Microelectron. J..

[33]  O. Lytvyn,et al.  Fabrication and properties of ZnO:Cu and ZnO:Ag thin films , 2007 .

[34]  A. M. Fox,et al.  Magneto-optical and transport studies of ZnO-based dilute magnetic semiconductors , 2007 .

[35]  Yanfa Yan,et al.  Doping of ZnO by group-IB elements , 2006 .

[36]  Bixia Lin,et al.  Enhancement of ultraviolet emissions from ZnO films by Ag doping , 2006 .

[37]  Sang Yeol Lee,et al.  Structural, electrical, and optical properties of p-type ZnO thin films with Ag dopant , 2006 .

[38]  D. Lincot,et al.  Oxygen reduction reaction on electrodeposited zinc oxide electrodes in KCl solution at 70 ◦ C , 2006 .

[39]  Hadis Morkoç,et al.  Ferromagnetism of ZnO and GaN: A Review , 2005 .

[40]  H. Morkoç,et al.  A COMPREHENSIVE REVIEW OF ZNO MATERIALS AND DEVICES , 2005 .

[41]  S. Jeong,et al.  Structural and optical properties of silver-doped zinc oxide sputtered films , 2005 .

[42]  A. MacDonald,et al.  Ferromagnetic semiconductors: moving beyond (Ga,Mn)As , 2005, cond-mat/0503185.

[43]  Yang Yang,et al.  The characteristics and photocatalytic activities of silver doped ZnO nanocrystallites , 2004 .

[44]  Charles M. Lieber,et al.  Growth of nanowire superlattice structures for nanoscale photonics and electronics , 2002, Nature.

[45]  B. Meyer,et al.  Valence-band ordering and magneto-optic exciton fine structure in ZnO , 2002 .

[46]  Daniel Lincot,et al.  Heteroepitaxial electrodeposition of zinc oxide films on gallium nitride , 1999 .

[47]  V. Barone,et al.  Toward reliable density functional methods without adjustable parameters: The PBE0 model , 1999 .