Structure and Morphology in Diffusion-Driven Growth of Nanowires: The Case of ZnTe

Pamela Rueda-Fonseca (1) , Edith Bellet-Amalric (1) , R. Vigliaturo , Martien den Hertog (2) , Yann Genuist (3) , Régis André (4) , Eric Robin , Alberto Artioli , Petr Stepanov , David Ferrand (4) , Kuntheak Kheng (1) , Serge Tatarenko (4) , Joel Cibert (4)

1 NPSC - Nanophysique et Semiconducteurs
2 NEEL - MRS - Matériaux, Rayonnements, Structure
3 NEEL- EpiCM - Epitaxie et couches minces
4 NEEL - NPSC - Nanophysique et Semiconducteurs

Gold-catalyzed ZnTe nanowires were grown at low temperature by molecular beam epitaxy on a ZnTe(111) B buffer layer, under different II/VI flux ratios, including with CdTe insertions. High-resolution electron microscopy and energy-dispersive X-ray spectroscopy (EDX) gave information about the crystal structure, polarity, and growth mechanisms. We observe, under stoichiometric conditions, the simultaneous presence of zinc-blende and wurtzite nanowires spread homogeneously on the same sample. Wurtzite nanowires are cylinder-shaped with a pyramidal-structured base. Zinc-blende nanowires are cone-shaped with a crater at their base. Both nanowires and substrate show a Te-ended polarity. Te-rich conditions favor zinc-blende nanowires, while Zn-rich suppress nanowire growth. Using a diffusion-driven growth model, we present a criterion for the existence of a crater or a pyramid at the base of the nanowires. The difference in nanowire morphology indicates lateral growth only for zinc-blende nanowires. The role of the direct impinging flux on the nanowire's sidewall is discussed

Domaines: Physique [physics]

Pamela Rueda-Fonseca, Edith Bellet-Amalric, R. Vigliaturo, Martien den Hertog, Yann Genuist, et al.. Structure and Morphology in Diffusion-Driven Growth of Nanowires: The Case of ZnTe. Nano Letters, 2014, 14 (4), pp.1877-1883. ⟨10.1021/nl4046476⟩. ⟨hal-01017404⟩