Axially-Resolved Luminescence Properties of Individual ZnSe Nanowires

• Published in: Journal of physical chemistry. C 2012-04, Vol.116 (15), p.8819-8823
• Main Authors: Zhuang, Junping, Liang, Yao, Xiao, X. D, Hark, S. K
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of nanofabrication; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Physics; Quantum wires
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp300051s

We investigated axially resolved near-band-edge (NBE) and deep-level (DL) photoluminescence of individual ZnSe nanowires, using the techniques of two-photon excited luminescence imaging and time-correlated single photon counting, in a laser scanning confocal microscope. While the images of nanowires formed from the NBE luminescence appears to be uniform, a bright tip and a dim tail are observed in the images formed from the DL luminescence. At all locations of the nanowires, the luminescence decays are found to be dominated by a fast process at early time, followed by a slow component later. In addition, we report a flattened “U” shape distribution of the lifetimes along the length of nanowire for the NBE emission, and an elongated “L” shape distribution for the DL emission. Possible explanations for these results, involving carrier recombination dynamics and possibly plasmonic enhancements, are discussed.