Growth of II–VI ZnSe/CdSe nanowires for quantum dot luminescence

• Published in: Journal of crystal growth 2013-09, Vol.378, p.233-237
• Main Authors: Bellet-Amalric, E., Elouneg-Jamroz, M., Rueda-Fonseca, P., Bounouar, S., Hertog, M. Den, Bougerol, C., André, R., Genuist, Y., Poizat, J.P., Kheng, K., Cibert, J., Tatarenko, S.
• Format: Article
• Language: English
• Subjects: A1. Growth Models; A1. Transmission electron microscopy; A3. Molecular beam epitaxy; B1. Nanowires; B1. Quantum dots; B2. Semiconducting II–VI material; Cadmium selenides; Condensed Matter; Cross-disciplinary physics: materials science; rheology; Droplets; Exact sciences and technology; Gold; Homogeneity; Intermetallics; Materials Science; Methods of crystal growth; physics of crystal growth; Nanoscale materials and structures: fabrication and characterization; Nanowires; Other topics in nanoscale materials and structures; Physics; Quantum dots; Quantum wires; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Zinc selenides
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2012.10.010

The growth of gold catalyzed ZnSe nanowires, with CdSe insertions, by molecular beam epitaxy is investigated. In situ reflection high energy electron diffraction and ex-situ transmission electron diffraction reveal that both during, the gold dewetting and the nanowire growth, the gold particles remain always in the solid phase. The nanowire growth proceeds by ledge flow at the gold/nanowire interface as observed ex-situ by the presence of two monolayers high steps at the interface. The nanowire diameters present a high homogeneity corresponding to the low dispersion of the gold droplets. Finally, a rather abrupt interface, of less than 1nm thick, is observed between the ZnSe barrier and the CdSe quantum dot allowing a high confinement of the excitons. All the above observations are compatible with a Vapor–Solid–Solid growth mode. ► Gold catalyzed ZnSe nanowires with CdSe insertions where grown by molecular beam epitaxy. ► The gold droplets remain in the solid phase during dewetting and nanowire growth. ► The nanowire growth proceeds by ledge flow at the gold/nanowire interface. ► CdSe quantum dot with abrupt interfaces allow high confinement of excitons. ► The nanowire growth mechanism is compatible with a Vapor–Solid–Solid growth mode.