title: Nanoscale Characterization of Carrier Dynamic and Surface Passivation in InGaN/GaN Multiple Quantum Wells on GaN Nanorods.
abstract: Using advanced two-photon excitation confocal microscopy, associated with time-resolved spectroscopy, we characterize InGaN/GaN multiple quantum wells on nanorod heterostructures and demonstrate the passivation effect of a KOH treatment. High-quality InGaN/GaN nanorods were fabricated using nanosphere lithography as a candidate material for light-emitting diode devices. The depth- and time-resolved characterization at the nanoscale provides detailed carrier dynamic analysis helpful for understanding the optical properties. The nanoscale spatially resolved images of InGaN quantum well and defects were acquired simultaneously. We demonstrate that nanorod etching improves light extraction efficiency, and a proper KOH treatment has been found to reduce the surface defects efficiently and enhance the luminescence. The optical characterization techniques provide depth-resolved and time-resolved carrier dynamics with nanoscale spatially resolved mapping, which is crucial for a comprehensive and thorough understanding of nanostructured materials and provides novel insight into the improvement of materials fabrication and applications.
authors: Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, UNSW Australia , Sydney 2052, Australia.
authors: Weijian
authors: W
authors: Chen
authors: Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, UNSW Australia , Sydney 2052, Australia.|Centre for Micro-Photonics, Swinburne University of Technology , Melbourne 3122, Australia.
authors: Xiaoming
authors: X
authors: Wen
authors: Max Planck Institute for the Science of Light, Günther-Scharowsky-Str. 1/Bau 24, 91058 Erlangen, Germany.|Institute of Optics, Information and Photonics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Staudtstr. 7/B2, 91058 Erlangen, Germany.
authors: Michael
authors: M
authors: Latzel
authors: Max Planck Institute for the Science of Light, Günther-Scharowsky-Str. 1/Bau 24, 91058 Erlangen, Germany.
authors: Martin
authors: M
authors: Heilmann
authors: Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, UNSW Australia , Sydney 2052, Australia.
authors: Jianfeng
authors: J
authors: Yang
authors: Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, UNSW Australia , Sydney 2052, Australia.
authors: Xi
authors: X
authors: Dai
authors: Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, UNSW Australia , Sydney 2052, Australia.
authors: Shujuan
authors: S
authors: Huang
authors: Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, UNSW Australia , Sydney 2052, Australia.
authors: Santosh
authors: S
authors: Shrestha
authors: Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, UNSW Australia , Sydney 2052, Australia.
authors: Robert
authors: R
authors: Patterson
authors: Max Planck Institute for the Science of Light, Günther-Scharowsky-Str. 1/Bau 24, 91058 Erlangen, Germany.|Institute of Nanoarchitectures for Energy Conversion, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Hahn-Meitner-Platz 1, 14109 Berlin, Germany.|Department of Physics, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany.
authors: Silke
authors: S
authors: Christiansen
authors: Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, UNSW Australia , Sydney 2052, Australia.
authors: Gavin
authors: G
authors: Conibeer
keywords: GaN; multiple quantum well; nanorods; nanoscale optical characterization; surface passivation; two-photon excitation